Study guide · General Building (B) · Framing and Structural Components
Framing and Structural: The Rules the Exam Asks For
About 36 minutes · 6 sections
What this guide covers
The orientation told you which chapters own which assemblies. This guide is the layer under it: the numbers, triggers, and limits the exam actually tests in framing. How much of a stud you can cut. How far apart the anchor bolts go. When a ridge is a beam. What a stair riser may measure. Two out of three framing questions cite a code section. This guide carries every one of those sections at the grain the questions test, plus the arithmetic the other third runs on.
Key terms
- Cripple wall
- A framed wall running from the top of the foundation to the underside of the first-story floor framing.
- Braced wall line
- A straight line through the plan that stands for where wall bracing resists sideways loads.
- Bearing partition
- An interior wall that carries load from above. Joists under one that runs parallel to them must be sized for it.
- Guard
- A barrier at the open side of a walking surface that keeps people from falling off the edge.
The rules the exam tests
16 rules · 8 minSubfloor and wall framing
Frame cripple walls over 4 feet with studs sized for an additional story.
A cripple wall is a framed wall running from the top of the foundation to the underside of the first-story floor framing above grade plane. Frame foundation cripple walls with studs no smaller than the studs above, and set them on continuous foundations. Where the wall exceeds 4 feet in height, use the stud size required for an additional story.
On the job
The definition itself comes from the code's definitions chapter; this section carries the duties. The exam tests the definition, the same-size-or-larger stud rule, and the number the rule turns on: the 4-foot height that bumps stud size up a story.
Exact wording
A cripple wall is a framed wall running from the top of the foundation to the underside of the first-story floor framing above grade plane. Foundation cripple walls must be framed of studs no smaller than the studs above, must sit on continuous foundations, and where they exceed 4 feet in height must use the stud size required for an additional story.
Residential Code § r602.9
Continuously sheathe any exterior cripple wall with studs under 14 inches.
Measure the stud height of an exterior cripple wall. If it is less than 14 inches, sheathe one side continuously with wood structural panels fastened to both plates per the fastening schedule, or frame the wall of solid blocking.
On the job
Short cripple walls are the weak story in an earthquake; the code answers with sheathing or solid blocking at the 14-inch line — the neighbor figure to the 4-foot rule.
Exact wording
Exterior cripple walls with a stud height less than 14 inches must be continuously sheathed on one side with wood structural panels fastened to both plates per the fastening schedule, or built of solid blocking.
Residential Code § r602.9
You count the whole cripple wall as an additional story when any segment exceeds 48 inches.
Measure each segment's height along the braced wall line. Where every segment along that line is 48 inches or less, the cripple walls may be redesignated as a first-story wall for bracing.
On the job
This is where the 4-foot cripple-wall number bites. R602.9 sizes the studs past 4 feet; R602.10 makes the wall a story for bracing past 48 inches — one tall segment converts the whole line.
Exact wording
For wall bracing, a cripple wall counts by its height. Where every cripple wall segment along a braced wall line is 48 inches or less, the cripple walls may be redesignated as a first-story wall. Where any segment exceeds 48 inches, the entire cripple wall counts as an additional story.
Residential Code § r602.10
Size the joists under a bearing partition that runs parallel to them.
Where double joists are spread apart for piping or vents, solid-block them full depth with lumber at least 2 inches nominal, spaced no more than 4 feet on center. A bearing partition running across the joists may not be offset from its supporting girder, wall, or partition by more than the joist depth, unless you size those joists for the added load.
On the job
A wall parallel to the joists loads one line of framing instead of many. The rule is size: the joists must be adequate for the load, and doubling is one way to get there, not the requirement. The 4-foot blocking spacing and the one-joist-depth offset are the neighbor figures.
Exact wording
Joists under a bearing partition that runs parallel to them must be sized to carry the load. Where double joists are spread apart for piping or vents, they must be solid-blocked full depth with lumber at least 2 inches nominal, spaced not more than 4 feet on center. A bearing partition running across the joists may not be offset from its supporting girder, wall, or partition by more than the joist depth unless the joists are sized for the added load.
Residential Code § r502.4
Stagger your top plate end joints at least 24 inches.
Cap wood stud walls with a double top plate that laps at corners and at intersections with bearing partitions. That lap is what makes the plate a continuous tie. Keep end joints offset at least 24 inches; the joints need not land over studs. Plates must be at least 2 inches nominal thick and as wide as the studs. You may use a single top plate instead only where it is tied at corners, at intersections, and at in-line splices per the code's splice table, and the rafters or joists are centered over the studs within 1 inch.
On the job
The 24-inch joint offset is the tested number. The overlap at corners is why the double plate works as a continuous tie.
Exact wording
Wood stud walls are capped with a double top plate that overlaps at corners and at intersections with bearing partitions. End joints in the top plates must be offset at least 24 inches, joints need not land over studs, and plates must be at least 2 inches nominal thick and as wide as the studs. A single top plate is permitted as an alternative only where it is tied at corners, intersections, and in-line splices per the code's splice table and the rafters or joists are centered over the studs within 1 inch.
Residential Code § r602.3.2
If you cut over half a top plate's width, fasten a metal tie across it.
In an exterior or interior bearing wall, if piping or ductwork cuts, drills, or notches the top plate by more than 50 percent of its width, fasten a galvanized metal tie at least 0.054 inch thick (16 gage) and 1-1/2 inches wide across the plate on each side of the opening. Use at least eight 10d nails at least 1-1/2 inches long at each side, or equivalent. The tie must extend at least 6 inches past the opening. You skip the tie only where wood structural panel sheathing covers that whole side of the wall at the notch.
On the job
The trigger is the 50-percent cut; the repair is the strap with its eight nails and 6-inch reach. The sheathing exception is the qualifier that flips an answer.
Exact wording
Where piping or ductwork in an exterior or interior bearing wall requires cutting, drilling, or notching the top plate by more than 50 percent of its width, a galvanized metal tie at least 0.054 inch thick (16 gage) and 1-1/2 inches wide must be fastened across the plate on each side of the opening with at least eight 10d nails at least 1-1/2 inches long at each side, or equivalent, extending at least 6 inches past the opening — unless the whole side of the wall at the notch is covered by wood structural panel sheathing.
Residential Code § r602.6.1
Notch a stud in a bearing wall no deeper than 25 percent of its depth.
An approved stud shoe installed per its manufacturer's instructions is the only exception to both the notching and boring limits. The 25 percent cap covers exterior walls and bearing partitions. Nonbearing partitions allow 40 percent of a single stud's depth.
On the job
Two percentages, sorted by whether the wall bears — the exam asks for the bearing-wall number and offers the nonbearing one as the distractor.
Exact wording
A stud in an exterior wall or bearing partition may not be notched deeper than 25 percent of its depth; a stud in a nonbearing partition, not deeper than 40 percent of a single stud's depth. The one exception to both the notching and boring limits is an approved stud shoe installed per its manufacturer's instructions.
Residential Code § r602.6
Bore a stud no deeper than 60 percent of its depth.
Measure that 60 percent on the stud's depth, and keep the hole edge at least 5/8 inch from the stud edge. Never bore in the same section as a cut or notch. In an exterior wall or bearing partition, a hole over 40 percent of the depth requires a doubled stud, and no more than two successive doubled studs may be bored that way.
On the job
Boring has its own numbers — 60 percent, 5/8 inch, and the 40-percent line that forces a doubled stud — distinct from the notching percentages next to them.
Exact wording
A bored hole in a stud may not exceed 60 percent of the stud depth, its edge must stay at least 5/8 inch from the stud's edge, and it may not sit in the same section as a cut or notch. In an exterior wall or bearing partition, a hole over 40 percent of the depth requires the stud to be doubled, and no more than two successive doubled studs may be bored that way.
Residential Code § r602.6
Support each header end with one or more .
The header tables also allow approved framing anchors in place of jack studs. End-nail the full-height stud beside each header end to the header. For exterior-wall headers, the table sets the minimum number of full-height studs at each end by header span, wind speed, and exposure category.
On the job
The exam tests what carries a header's end: the jack stud, or an approved anchor in its place. The full-height count is the table's job, not memory's.
Exact wording
Headers must be supported at each end by one or more jack studs, or by approved framing anchors per the header tables. The full-height stud next to each end of the header is end-nailed to the header, and the minimum number of full-height studs at each end of an exterior-wall header is set by table according to the header span and the wind speed and exposure category.
Residential Code § r602.7.5
Never notch a solid-lumber joist, rafter, or beam in the middle third of its span.
The same limits apply to joists, rafters, and beams alike. No notch may be deeper than one-sixth of the member's depth or longer than one-third of the depth. End notches may be no deeper than one-fourth of the depth. Bored holes may be no larger than one-third of the depth, and they must stay at least 2 inches from the top or bottom edge, from any other hole, and from any notch. Do not notch the tension side of a member nominal 4 inches or thicker except at the ends.
On the job
Every fraction here is exam material: one-sixth, one-third, one-fourth, and the 2-inch clearances. The middle-third ban is the reason — bending stress peaks at mid-span.
Exact wording
Notches in solid-lumber joists, rafters, and beams may not exceed one-sixth of the member's depth, may not be longer than one-third of the depth, and may not be located in the middle third of the span. End notches may not exceed one-fourth of the depth. Bored holes may not exceed one-third of the depth and must stay at least 2 inches from the top or bottom edge, from any other hole, and from any notch. Members nominal 4 inches or thicker may not be notched on the tension side except at the ends.
Residential Code § r502.8.1
You fireblock concealed stud spaces horizontally at least every 10 feet.
In combustible construction, cuts off concealed draft openings. In wood-framed construction you fireblock concealed stud spaces vertically at ceiling and floor levels, and horizontally no more than 10 feet apart; where concealed vertical and horizontal spaces interconnect, such as soffits, drop ceilings, and cove ceilings; in concealed spaces between stair stringers at the top and bottom of the run; and around vents, pipes, ducts, cables, and wires at ceiling and floor level. Use approved material that resists the free passage of flame and products of combustion. Loose-fill insulation is not a fireblock unless it has been tested for that use. Except at those penetrations, use one of the listed materials: 2-inch nominal lumber, two layers of 1-inch lumber, wood structural panel, particleboard, 1/2-inch gypsum board, 1/4-inch cement board, or batts of mineral wool or glass fiber held in place.
On the job
The 10-foot horizontal interval and the named locations are what the exam asks. Fireblocking stops movement between spaces; draftstopping subdivides one big space — two different jobs.
Exact wording
In combustible construction, fireblocking cuts off concealed draft openings. In wood-framed construction it is required in concealed stud spaces vertically at ceiling and floor levels and horizontally at intervals not exceeding 10 feet; at interconnections between concealed vertical and horizontal spaces such as soffits, drop ceilings, and cove ceilings; in concealed spaces between stair stringers at the top and bottom of the run; and around vents, pipes, ducts, cables, and wires at ceiling and floor level, filled with an approved material that resists the free passage of flame and products of combustion. Loose-fill insulation is not a fireblock unless it has been tested for that use. Except at those penetrations, fireblocking is one of the code's listed materials: 2-inch nominal lumber, two layers of 1-inch, wood structural panel, particleboard, 1/2-inch gypsum board, 1/4-inch cement board, or batts of mineral wool or glass fiber held in place.
Residential Code § r302.11
a concealed floor-ceiling space into areas of no more than 1,000 square feet.
Draftstops are required in combustible construction where usable space sits both above and below the concealed floor-ceiling space, and they must divide it into approximately equal areas, none over 1,000 square feet. In an assembly enclosed by a floor above and a ceiling below, draftstopping is required where the ceiling is suspended under the floor framing, or where the floor framing is open-web truss or perforated members. Use at least 1/2-inch gypsum board, 3/8-inch wood structural panels, or other approved materials, adequately supported and installed parallel to the floor framing unless the building official approves otherwise.
On the job
The 1,000-square-foot limit is the tested figure; the two triggering conditions and the 1/2-inch and 3/8-inch material minimums are its neighbors.
Exact wording
In combustible construction where there is usable space both above and below a concealed floor-ceiling space, draftstops must divide that concealed space so no area exceeds 1,000 square feet, in approximately equal areas. In an assembly enclosed by a floor above and a ceiling below, draftstopping is required where the ceiling is suspended under the floor framing or where the floor framing is open-web truss or perforated members. Draftstopping materials are at least 1/2-inch gypsum board, 3/8-inch wood structural panels, or other approved materials, adequately supported, installed parallel to the floor framing unless the building official approves otherwise.
Residential Code § r302.12
The rim joist runs on edge across the cut ends of the floor joists.
The rim joist is also called the , and it is fastened along the outer edge of a wood-framed floor platform. It closes the joist ends, holds the joists upright, and gives the wall plate above a continuous bearing.
On the job
The rim joist is the member the deck ledger bolts to and the wall sits on — the exam names it by position.
Exact wording
The rim joist, also called the band joist, is set on edge along the outer edge of a wood-framed floor platform and fastened across the cut ends of the joists; it closes the joist ends, holds them upright, and gives the wall plate above a continuous bearing.
Standard trade practice
Cripple studs fill the space above a header and below a window's rough sill.
Cripple studs are cut studs. They run from the header up to the top plate, and from the bottom plate up to a window's rough sill. That keeps stud spacing continuous through the opening, so sheathing and finish have backing.
On the job
Cripple studs sit above headers and below sills; a cripple wall is a different thing — a short foundation wall under the first floor.
Exact wording
Cripple studs are the cut studs that fill the space between a header and the top plate, and the space between the bottom plate and the rough sill below a window; they keep the stud spacing continuous through the opening so sheathing and finish have backing.
Standard trade practice
Mark the stud locations on the top and bottom plates at the same time.
When you lay out a wall, cut both plates to length, then hold them together edge to edge for the marking. One set of marks across the pair gives matching top and bottom layouts, so every stud stands plumb.
On the job
One set of marks across both plates cannot disagree.
Exact wording
When laying out a wall, the top and bottom plates are cut to length, held together edge to edge, and the stud locations are marked across both at the same time, so the top and bottom layouts match exactly and the studs stand plumb.
Standard trade practice
Set every floor joist crown up. A joist set crown down sags deeper under load.
The crown is the slight upward bow along one edge of a solid-sawn joist. Sight down the edge to find it, then set that bow up so the subfloor, finish floor, and live load push it down toward level instead of deepening a sag.
On the job
Lumber is rarely straight; a consistent crown up lets the load flatten the floor.
Exact wording
Solid-sawn floor joists with a slight crown along one edge are sighted and installed crown up, so the weight of the subfloor, the finish floor, and the live load pushes the bow down toward level rather than deepening a sag.
Standard trade practice
Take away
9 rules · 4 minRoof framing
Make your ridge board at least 1-inch nominal thick and as deep as the rafter cut.
A ridge board only connects opposing rafters. Make it at least 1 inch nominal thick and at least as deep as the rafter's cut end. Where ceiling joists or do not provide the continuous ties across the structure that the code requires, the ridge must instead sit on a wall, or be a ridge beam designed by accepted engineering practice and supported at each end by a wall or column.
On the job
The exam splits the board from the beam. A board is a nailing surface with two dimensional minimums. Whenever nothing ties the rafters' feet together, the ridge must gain support: from a wall below, or from a designed ridge beam carried at each end by a wall or column.
Exact wording
A ridge board that connects opposing rafters must be at least 1 inch nominal thick and at least as deep as the cut end of the rafter. Where ceiling joists or rafter ties do not provide the continuous ties across the structure that the rafter-connection section requires, the ridge must instead be supported by a wall or by a ridge beam designed by accepted engineering practice and supported at each end by a wall or column.
Residential Code § r802.3
Install in the upper third of the attic space.
Where collar ties connect opposing rafters, use stock at least 1 inch by 4 inches nominal and space them no more than 4 feet on center. You may use ridge straps instead: at least 1-1/4 inch by 20 gage, nailed to the top edge of each rafter with at least three 10d common nails, and the closest nail at least 2-3/8 inches from the rafter's end.
On the job
Upper third, 1x4 minimum, 4 feet on center — all three are testable. The ridge-strap substitute is the qualifier the exam likes to test in reverse.
Exact wording
Where collar ties connect opposing rafters, they go in the upper third of the attic space, must be at least 1 inch by 4 inches nominal, and are spaced not more than 4 feet on center. Ridge straps may replace collar ties: at least 1-1/4 inch by 20 gage, nailed to the top edge of each rafter with at least three 10d common nails, the closest nail at least 2-3/8 inches from the rafter's end.
Residential Code § r802.4.6
You need a designed ridge beam when parallel ceiling joists sit above the bottom third.
Three cases decide what holds the rafter feet together. Parallel ceiling joists in the bottom third of the rafter height are the continuous tie themselves — install them per the code's figure and fasten them to the rafters per the heel-joint table. Non-parallel ceiling joists give you a choice: tie the rafters across the structure with rafter ties, or design the ridge as a beam.
On the job
Rafters push the walls outward at the plate. The exam tests which condition gets which remedy: low parallel joists tie the building themselves; high parallel joists force a ridge beam with no rafter-tie option; non-parallel joists allow rafter ties or a ridge beam.
Exact wording
Three cases decide what holds the rafter feet together. Where ceiling joists run parallel to the rafters and sit in the bottom third of the rafter height, they are installed per the code's figure and fastened to the rafters per the heel-joint table, and they provide the continuous tie. Where parallel ceiling joists sit above the bottom third, the ridge must be designed as a beam. Where the ceiling joists do not run parallel to the rafters, the rafters must be tied across the structure with rafter ties, or the ridge must be designed as a beam.
Residential Code § r802.5.2
Space your wood rafter ties no more than 24 inches on center.
Install wood rafter ties per the rafter and ceiling-joist connection table. Each tie is at least 2 inches by 4 inches, and 24 inches on center is the maximum spacing. Or use another approved rafter-tie method.
On the job
2x4 and 24 inches on center are the numbers; note the contrast with collar ties at 1x4 and 4 feet.
Exact wording
Wood rafter ties must be at least 2 inches by 4 inches, installed per the rafter and ceiling-joist connection table at a maximum of 24 inches on center; other approved rafter-tie methods are permitted.
Residential Code § r802.5.2.2
Nail the lap per the heel-joint table where ceiling joists form the continuous tie.
Lap ceiling joists at least 3 inches, or butt them over a bearing partition or beam. Toenail them to the bearing member. Butted joists carrying the continuous tie across the building need a connection of equivalent capacity.
On the job
The 3-inch lap is the neighbor figure to the tie rule: joists only tie the building if their lap carries the load through.
Exact wording
Ceiling joists are lapped at least 3 inches, or butted over bearing partitions or beams, and toenailed to the bearing member. Where the ceiling joists provide the continuous tie across the building, lapped joists are nailed together per the heel-joint table and butted joists are tied with a connection of equivalent capacity.
Residential Code § r802.5.2
You need a registered design professional's approval before you cut or drill any truss member.
Every truss member is designed as part of one engineered assembly, so notching, splicing, or altering a member in any way also requires a registered design professional's approval. Adding load beyond the truss's design load — HVAC equipment or a water heater — is not permitted without verification that the truss can carry it.
On the job
Every truss member is designed; the exam tests that a field cut needs an engineer's approval, and that added equipment needs verification.
Exact wording
Truss members may not be cut, notched, drilled, spliced, or otherwise altered in any way without the approval of a registered design professional. Alterations that add load beyond the truss's design load — HVAC equipment or a water heater, for example — are not permitted without verification that the truss can carry the added load.
Residential Code § r802.10.4
A valley rafter carries the shortened rafters at an inside corner.
Where two roof planes meet at an inside corner, the valley rafter is the sloped framing member running from the wall plate up to the ridge. The shortened rafters on each side are valley jacks, cut to bear on it.
On the job
Hip at the outside corner, valley at the inside corner: both carry jack rafters, and the exam asks which is which.
Exact wording
A valley rafter is the sloped framing member at the inside corner where two roof planes meet; it runs from the wall plate at the corner up to the ridge, and the shortened rafters on each side of the valley — the valley jacks — are cut to bear on it.
Standard trade practice
Fit the first common rafter before you mark any of the others.
Cut the first common rafter to the figured length. Set it at the ridge and plate to check that the plumb cut, seat cut, and overhang land where they should. Once it fits, mark all the other rafters from that pattern.
On the job
One test fit catches a layout error before it is cut twenty times.
Exact wording
After the first common rafter is laid out and cut from the figured length, it is set in place at the ridge and plate to check that the plumb cut, seat cut, and overhang land where they should; once it fits, that rafter becomes the pattern from which all the others are marked.
Standard trade practice
Shorten each common rafter by half the ridge board's thickness.
The two opposing rafters and the ridge board together have to fill the span, so each rafter loses its share. Take that deduction at right angles to the plumb cut — the vertical cut face where the rafter meets the ridge — so the cut slides straight back.
On the job
The deduction is made square to the plumb line, not along the rafter's edge, so the cut slides back parallel to the mark.
Exact wording
When common rafters butt into a ridge board, each rafter is shortened by half the ridge thickness, measured at right angles to the ridge plumb cut, so the two opposing rafters and the ridge board together fill the span.
Standard trade practice
Take away
9 rules · 7 minSeismic hardware
You anchor sill plates with bolts no more than 6 feet on center.
Bolt sill plates on continuous foundations, and sole plates at exterior walls and interior on monolithic slabs, using bolts at least 1/2 inch in diameter. Space them no more than 6 feet on center, embed each at least 7 inches into the concrete or grouted masonry, and set each in the middle third of the plate's width with a nut and washer tightened. Approved anchors or straps spaced to give equivalent anchorage are permitted instead.
On the job
Three tested numbers in one sentence — 1/2 inch, 6 feet, 7 inches — plus the middle-third placement. The exam asks for each of them separately.
Exact wording
Wood sill plates on continuous foundations, and wood sole plates at exterior walls and at interior braced wall panels on monolithic slabs, are anchored with anchor bolts at least 1/2 inch in diameter, spaced not more than 6 feet on center, extending at least 7 inches into the concrete or grouted masonry, and located in the middle third of the plate's width, each with a nut and washer tightened. Approved anchors or straps spaced to give equivalent anchorage are permitted.
Residential Code § r403.1.6
Put two anchor bolts in every plate piece. Keep one within 12 inches of each end.
A plate piece is one individual length of sill or sole plate. The bolt near each end must also sit at least seven bolt diameters back from that end. Two exceptions: a wall 24 inches or shorter connecting offset braced wall panels takes one bolt in the center third of the plate, and a wall 12 inches or shorter needs no anchor bolts. Fasten each of those short walls to the adjacent panels at the corners per the fastening schedule.
On the job
Two per piece and 12 inches from the ends are the figures the exam tests most; the seven-diameter minimum is the neighbor that keeps the end bolt from splitting the plate.
Exact wording
Every plate section gets at least two anchor bolts, with one bolt located not more than 12 inches, and not less than seven bolt diameters, from each end of the plate section. Two short-wall exceptions: a wall 24 inches or shorter connecting offset braced wall panels needs one bolt in the center third of the plate, and one 12 inches or shorter may go without anchor bolts, each attached to the adjacent panels at the corners per the fastening schedule.
Residential Code § r403.1.6
Use a on every anchor bolt along a required braced wall line.
In Seismic Design Categories D0, D1, and D2 — and in wood light-frame townhouses in Category C — wood light-frame foundation anchorage adds two requirements. The first is plate washers, per the braced-wall section, on all anchor bolts along required braced wall lines, except where approved anchor straps are used. The second applies only to buildings over two stories: space the anchor bolts no more than 4 feet apart. The same 6-foot spacing and 12-inch end distance also extend to interior braced wall plates and interior bearing wall sole plates on continuous foundations.
On the job
California's seismic categories add the plate washer and tighten spacing to 4 feet on taller buildings — the qualifiers the exam attaches to the base rule.
Exact wording
For wood light-frame structures in Seismic Design Categories D0, D1, and D2 (and wood light-frame townhouses in C), foundation anchorage adds two things: plate washers per the braced-wall section on all anchor bolts along required braced wall lines, except where approved anchor straps are used; and a maximum bolt spacing of 4 feet for buildings over two stories. The same 6-foot spacing and 12-inch end distance also extend to interior braced-wall plates and interior bearing-wall sole plates on continuous foundations.
Residential Code § r403.1.6
In D, bolt sill plates down with 3-by-3 plate washers.
Along braced wall lines, use anchor bolts at least 1/2 inch in diameter, each with a steel plate washer between the sill plate and the nut. Or use approved load-rated anchor straps spaced to give equivalent anchorage. Plate washers are at least 0.229 inch by 3 inches by 3 inches. You may diagonally slot the hole up to 3/16 inch wider than the bolt and up to 1-3/4 inches long, only if a standard cut washer sits between the plate washer and the nut.
On the job
The 3-by-3 plate washer is the tested spec: it spreads the bolt's load so the sill does not split when the wall is pushed sideways.
Exact wording
In Seismic Design Category D, sill plates along braced wall lines are anchored with at least 1/2-inch anchor bolts with steel plate washers between the plate and the nut, or with approved load-rated anchor straps spaced to give equivalent anchorage. Plate washers are at least 0.229 inch by 3 inches by 3 inches; the hole may be diagonally slotted up to 3/16 inch wider than the bolt and up to 1-3/4 inches long if a standard cut washer sits between the plate washer and the nut.
Building Code § 2308.7.1.1
ACI 318 governs every anchor in concrete. Adhesive and screw anchors are included.
Anchor to concrete under ACI 318, as supplemented by Section 1905 of the Building Code's concrete chapter. It covers cast-in bolts and post-installed anchors: expansion, undercut, screw, and adhesive.
On the job
The exam tests that anchors are a designed system under one standard, ACI 318, and which anchor types the rule reaches. This much governs every job; the qualification and proof-test rules that follow are OSHPD-only.
Exact wording
Anchoring to concrete follows ACI 318 as supplemented in Section 1905 of the Building Code's concrete chapter. It covers cast-in bolts and post-installed expansion, undercut, screw, and adhesive anchors.
Building Code § 1901.3
On hospital work you proof test every structural post-installed anchor. Ordinary houses are outside these rules.
A proof test loads the installed anchor and holds the load 15 seconds with no discernible movement. Under the OSHPD 1R, 2, and 5 provisions, qualified mechanical and adhesive anchors are deemed to comply, and a removed mechanical anchor may not be reset. Test 100 percent of structural post-installed anchors, except sill plate or bottom track bolting, where 10 percent are tested. Run tests unconfined, with the frame kept back 1.5 times the embedment; adhesive anchors may be tested confined when the approved documents show concrete breakout does not control. If any anchor fails, test all of that type until twenty in a row pass. These provisions cover hospital and health-facility work, never an ordinary house or commercial job.
On the job
The 10-percent figure is in the code and a question can carry it, but only inside the OSHPD scope. The exam trap is mapping it onto an epoxy sill-bolt retrofit on a house, where it does not apply. Scope first, figure second.
Exact wording
For hospital and health-facility work only — the OSHPD 1R, 2, and 5 provisions — post-installed anchors also get proof tests. These rules do not govern an ordinary house or commercial job. Under them, qualified mechanical and adhesive anchors are deemed to comply, a removed mechanical anchor may not be reset, and structural post-installed anchors are 100 percent proof tested, except sill plate or bottom track bolting, where 10 percent are tested. Tests run unconfined, with the frame kept back 1.5 times the embedment, holding the load 15 seconds with no discernible movement; adhesive anchors may test confined when the approved documents show concrete breakout does not control. If any anchor fails, all of that type are tested until twenty in a row pass.
Building Code § 1901.3
You design and build wood-frame shear walls to SDPWS even when panels are stapled.
SDPWS is the AWC Special Design Provisions for Wind and Seismic, a lateral-design standard. The code also gives three staple shear tables you may use. For wind design, you may raise the wood-panel and fiberboard staple tables 40 percent.
On the job
The exam asks which standard a shear wall follows. The answer is SDPWS, a lateral-design standard, not a panel standard. The staple tables are a permission the code adds beside it.
Exact wording
Wood-frame shear walls are designed and built to AWC SDPWS, the Special Design Provisions for Wind and Seismic. Where panels are stapled instead of nailed, SDPWS still governs, and the code's three staple shear tables may be used. The wood-panel and fiberboard staple tables may be raised 40 percent for wind design.
Building Code § 2306.3
Back every panel edge with framing to use the staple shear table values.
Back every panel edge with 2-inch nominal or wider framing, and fasten at the tabulated spacing along every panel edge. On intermediate framing, space fasteners 6 inches on center for 3/8-inch and 7/16-inch panels on studs 24 inches on center, and 12 inches on center otherwise. Where edge fasteners are 2 inches on center, framing at adjoining panel edges must be 3-inch nominal or wider. In Seismic Design Categories D, E, and F where shear values exceed 350 pounds per foot, framing receiving edge fastening from abutting panels must be a single 3x member or two 2x members fastened together. Staples on wood structural panels need at least a 7/16-inch crown, set parallel to the framing; staples for gypsum or wire lath need a 3/4-inch crown. The wood-panel table is written for Douglas Fir-Larch or Southern Pine framing; for other species, read the Structural I row and multiply by 0.82 when specific gravity is 0.42 or more, or by 0.65 for all others. Multiply wood-panel values by 0.63 for normal load duration and by 0.56 for permanent. Cut gypsum and lath values 25 percent for normal loading; those rows assume studs 16 inches on center unless the row says 24. ASCE 7 Section 12.2.1 limits seismic use of gypsum and lath shear walls.
On the job
Edge fastening means every panel edge, each landing on framing — the tested fact, stated in the notes to the staple tables. The 3x framing rule is a trigger, not a baseline: it fires at 2-inch edge spacing, or above 350 pounds per foot in Seismic Design Categories D, E, and F.
Exact wording
The staple shear tables come with conditions. Panel edges are backed by 2-inch nominal or wider framing, and fasteners run at the tabulated spacing along every panel edge. Along intermediate framing the spacing is 6 inches on center for 3/8-inch and 7/16-inch panels on studs 24 inches on center, and 12 inches otherwise. Where edge fasteners are 2 inches on center, framing at adjoining panel edges must be 3 inches nominal or wider. In Seismic Design Categories D, E, and F where shear values exceed 350 pounds per foot, framing receiving edge fastening from abutting panels must be a single 3x member or two 2x members fastened together. Staples on wood structural panels need at least a 7/16-inch crown, set parallel to the framing; staples for gypsum or wire lath need a 3/4-inch crown. The wood-panel table is written for Douglas Fir-Larch or Southern Pine framing; for other species, read the Structural I row and multiply by 0.82 (specific gravity 0.42 or more) or 0.65 (all others). The wood-panel table's values are multiplied by 0.63 for normal and 0.56 for permanent load duration; the gypsum and lath table's values are cut 25 percent for normal loading and assume studs at 16 inches on center unless the row says 24. Seismic use of gypsum and lath shear walls is limited by ASCE 7 Section 12.2.1.
Building Code § 2306.3
You can start a braced wall panel up to 10 feet from the line's end.
A ties a braced wall panel's edge stud down to the foundation or framing below. That 10-foot offset is allowed in Seismic Design Categories D0 through D2 for the wood-structural-panel, brick-veneer wood-structural-panel (detached one- and two-family dwellings only, in D0 through D2), and continuous-sheathing methods — but not structural fiberboard, which Method CS-SFB bars in D0 through D2. It works only if each end of the braced wall line has one of two things: a panel at least 24 inches wide of those same methods on each side of the building corner, or an 1,800-pound hold-down device fastened to the edge stud of the panel closest to the corner and to the foundation or framing below. Method ABW, the alternate braced wall, takes its hold-down forces from Table R602.10.6.1; the portal frame methods follow their own construction sections.
On the job
The exam tests what a hold-down is and where it goes; the 1,800-pound end-condition device is the figure the code states, in the seismic categories and methods it attaches it to.
Exact wording
A hold-down device ties the stud at the edge of a braced wall panel down to the foundation or framing below. In Seismic Design Categories D0 through D2, a braced wall panel of the wood-structural-panel, brick-veneer wood-structural-panel (in D0 through D2, detached one- and two-family dwellings only), or continuous-sheathing methods (not structural fiberboard, which Method CS-SFB bars in D0 through D2) may begin up to 10 feet from the end of its braced wall line if each end meets one of two conditions: a panel at least 24 inches wide of the named methods on each side of the building corner, or an 1,800-pound hold-down device fastened to the edge stud of the panel closest to the corner and to the foundation or framing below. Method ABW, the alternate braced wall, takes its hold-down forces from Table R602.10.6.1; the portal frame methods take their requirements from their own construction sections.
Residential Code § r602.10
Take away
5 rules · 3 minSiding and stucco
Apply three coats of cement plaster over metal lath. Over masonry you use two.
Apply cement plaster per ASTM C926. Over metal or wire lath use at least three coats; over masonry, concrete, treated or decay-resistant wood, or gypsum backing, at least two. Where the surface is completely covered or concealed, two coats work if total thickness meets the table. Keep each coat moist 48 hours before the next, unless installed per ASTM C926. On two-coat work, the finish coat waits seven days after the first coat; on three-coat work, the second coat waits 48 hours.
On the job
Three coats over lath, two over masonry — the tested pair. The code also sets the clock between coats: 48 hours moist, seven days before a two-coat finish, 48 hours before a three-coat second coat.
Exact wording
Cement plaster is applied per ASTM C926. Over metal lath or wire lath it must be at least three coats; over masonry, concrete, treated or decay-resistant wood, or gypsum backing, at least two coats. Where the plaster surface is completely covered or concealed, two coats suffice if the total thickness meets the table. Each coat stays moist for 48 hours before the next, unless the work is installed per ASTM C926. The finish coat of two-coat plaster waits seven days after the first coat; the second coat of three-coat plaster waits 48 hours.
Residential Code § r703.7
Set the at least 4 inches above earth or 2 inches above paving.
On exterior stud walls, install a corrosion-resistant weep screed of at least 0.019 inch (No. 26 gage) or plastic, with a vertical attachment flange at least 3-1/2 inches, at or below the foundation plate line. Keep it at least 4 inches above earth or 2 inches above paved areas, and let trapped water drain out. Lap the over the flange; the lath covers the flange and stops there.
On the job
The 4-inch and 2-inch clearances and the lap order — barrier over the flange, lath stopping on it — are what the exam tests.
Exact wording
A corrosion-resistant weep screed of at least 0.019 inch (No. 26 gage) or plastic, with a vertical attachment flange of at least 3-1/2 inches, is required at or below the foundation plate line on exterior stud walls. It sits at least 4 inches above earth or 2 inches above paved areas and must let trapped water drain out. The water-resistive barrier laps the attachment flange, and the exterior lath covers and stops on the flange.
Residential Code § r703.7.2
Run two layers of 10-minute paper behind stucco. Use one 60-minute layer only with a separation.
Outside the marine climate zones the code's table names, you have two routes behind stucco. The first option: two layers of 10-minute Grade D paper, or the equal of two layers of the Type I barrier standard, installed as separate continuous planes, with flashing installed per the flashing section and directed to drain to the barrier between the layers. The second option: one layer of 60-minute Grade D paper, or the equal of one layer of the Type II barrier standard, separated from the stucco by foam sheathing, another non-water-absorbing layer, or a drainage space or means of drainage meeting the code's drainage section, with that flashing directed to the barrier's exterior side.
On the job
Both options comply. The 60-minute single layer is compliant only WITH one of the listed separations: foam sheathing, another non-absorbing layer, or a drainage space or means of drainage. That is where a question turns.
Exact wording
Outside the marine climate zones the code's table names, the water-resistive barrier behind stucco is either two layers of 10-minute Grade D paper (or equal to two layers of the Type I barrier standard), installed as separate continuous planes, with flashing installed per the flashing section and meant to drain to the barrier directed between the layers; or one layer of 60-minute Grade D paper (or equal to one layer of the Type II standard) separated from the stucco by foam sheathing, another non-water-absorbing layer, or a drainage space or means of drainage meeting the code's drainage section, with such flashing directed to the barrier's exterior side.
Residential Code § r703.7.3.1
Press the scratch coat into the lath so it keys. Flatten the wall later.
Over metal lath, cement plaster goes on in three coats. Press the first — the scratch coat — into the lath so it keys through the mesh. Score it horizontally so the brown coat bonds. Brown straightens the wall; finish gives texture.
On the job
Each coat has one job, and the scratch coat's is the mechanical bond to the lath.
Exact wording
Over metal lath, cement plaster is applied in three coats, and the first is the scratch coat: pressed into the lath so the plaster keys through the mesh, then scored horizontally so the brown coat can bond to it; the brown coat straightens the wall and the finish coat gives the texture.
Standard trade practice
Run self-furring expanded metal lath across the studs with the cups facing up.
The cups are the small dimples in the mesh, facing up so plaster keys behind the lath. Each sheet's long dimension runs across several studs or other supports, tying them together, and you fasten it at every support.
On the job
Across the supports and cups up: the sheet bridges the studs and the plaster hooks over the mesh instead of sliding off it.
Exact wording
Self-furring expanded metal lath is hung with its long dimension running across the studs or other supports, so each sheet ties several supports together and is fastened at every one, and with the small cups formed in the mesh facing up, so the plaster pushed into the mesh keys behind it.
Standard trade practice
Take away
10 rules · 5 minDecks and stairs
In preservative-treated wood, use only corrosion-resistant fasteners, nuts, and washers.
The acceptable fastener materials are hot-dipped zinc-coated galvanized steel, stainless steel, silicon bronze, or copper; staples must be stainless steel. Connector coatings follow the manufacturer's recommendations, and with none, at least ASTM A653 type G185 galvanized steel. Exceptions: steel bolts 1/2 inch or larger; fasteners other than nails, staples, and timber rivets may be mechanically deposited zinc-coated steel of at least ASTM B695 Class 55; and plain carbon steel fasteners are allowed in SBX/DOT or zinc-borate treated wood in interior, dry environments.
On the job
Treated lumber's chemicals eat plain steel; the exam tests the fastener list and the G185 minimum, with the 1/2-inch-bolt exception as the qualifier.
Exact wording
Fasteners for preservative-treated wood, nuts and washers included, must be hot-dipped zinc-coated galvanized steel, stainless steel, silicon bronze, or copper; staples must be stainless steel. Connector coatings follow the manufacturer's recommendations, and absent those, at least ASTM A653 type G185 galvanized steel. The exceptions: steel bolts 1/2 inch or larger; fasteners other than nails, staples, and timber rivets may be mechanically deposited zinc-coated steel of at least ASTM B695 Class 55; and plain carbon steel fasteners are allowed in SBX/DOT or zinc-borate treated wood in interior, dry environments.
Residential Code § r304.3.1
Use a 2x8 or larger treated deck ledger fastened to the .
Use No. 2 or better pressure-treated Southern pine, incised treated hem-fir, or naturally durable decay-resistant wood, in a 2x8 or larger nominal size. The ledger may carry no concentrated loads from beams or girders and may not be supported on stone or masonry veneer. Fasten it to a band joist — 2-inch solid-sawn spruce-pine-fir or better, or a 1-inch engineered rim board — that bears fully on the primary structure. Where you fasten per the connection table, the fasteners meet the deck fastener section: 1/2-inch lag screws or bolts at that table's spacing, placed per the placement table and figures. Predrill lag holes 1/2 inch through the ledger and any sheathing, and 5/16 to 3/8 inch through the band joist.
On the job
The ledger carries the whole inboard edge of the deck. The exam tests the 2x8 minimum, the veneer prohibition, and the lag-screw predrill.
Exact wording
Deck ledgers are at least 2x8 nominal, No. 2 or better pressure-treated Southern pine, incised treated hem-fir, or decay-resistant naturally durable wood. They may not carry concentrated loads from beams or girders and may not be supported on stone or masonry veneer. Ledgers fasten to a band joist — 2-inch solid-sawn spruce-pine-fir or better, or a 1-inch engineered rim board — that bears fully on the primary structure. Where fastened per the connection table, the fasteners meet the deck fastener section and follow the placement table and figures: 1/2-inch lag screws or bolts at the table's spacing, with lag holes predrilled 1/2 inch through the ledger and any sheathing and 5/16 to 3/8 inch through the band joist.
Residential Code § r507.9
You must transfer deck lateral loads to the ground through tension devices.
The load may instead go to a structure that can carry it to the ground. Either install at least two hold-down tension devices per deck, within 24 inches of each end, each with an allowable stress design capacity of at least 1,500 pounds, or install hold-down devices at four or more locations at 750 pounds each.
On the job
Ledger bolts carry vertical load; the lateral load gets its own connection. The exam tests the two devices at 1,500 pounds within 24 inches of the ends.
Exact wording
Deck lateral loads must be transferred to the ground or to a structure that can carry them there. Under the first figure path, hold-down tension devices go in at least two locations per deck, within 24 inches of each end, each with an allowable stress design capacity of at least 1,500 pounds; under the second, at least four locations at 750 pounds each.
Residential Code § r507.9.2
Keep every riser in one flight within 3/8 inch of the others.
A flight is the run of steps between two landings. No riser may exceed 7-3/4 inches, measured vertically between the leading edges of adjacent treads. Each tread must be at least 10 inches deep, measured horizontally between the vertical planes of the foremost projections of adjacent treads, and the greatest tread in the flight may not exceed the smallest by more than 3/8 inch either. A nosing's radius may not exceed 9/16 inch, or its bevel 1/2 inch. Nosings must project between 3/4 inch and 1-1/4 inches, except where the tread is 11 inches or deeper; at open risers the projection may exceed 1-1/4 inches. Measure all of this without carpets, rugs, or runners. Spiral stairways and winder treads follow their own rules.
On the job
7-3/4, 3/8, and 10 are the three numbers the exam tests most in this section, and uniformity is the rule behind the riser-count arithmetic.
Exact wording
Riser height may not exceed 7-3/4 inches, measured vertically between the leading edges of adjacent treads, and the greatest riser in a flight may not exceed the smallest by more than 3/8 inch. Tread depth must be at least 10 inches, measured horizontally between the vertical planes of the foremost projections of adjacent treads, with the same 3/8-inch uniformity rule. The nosing's radius may not exceed 9/16 inch, or its bevel 1/2 inch. A nosing must project between 3/4 inch and 1-1/4 inches, except where the tread is 11 inches or deeper; at open risers the projection may exceed 1-1/4 inches. Dimensions are measured exclusive of carpets, rugs, or runners. Spiral stairways and winder treads follow their own rules.
Residential Code § r318.7.5
Open-riser openings more than 30 inches above the floor must not pass a 4-inch sphere.
Spiral stairways are the exception: the opening between adjacent treads is not limited. On other stairways, an open-riser opening more than 30 inches vertically above the floor or grade below may not pass a 4-inch-diameter sphere.
On the job
The 30-inch height and the 4-inch sphere recur across guards and stairs; the spiral exception is the qualifier.
Exact wording
At open risers, openings located more than 30 inches vertically above the floor or grade below may not pass a 4-inch-diameter sphere; the opening between adjacent treads is not limited on spiral stairways.
Residential Code § r318.7.5
Install a handrail on any flight with four or more risers. One side is enough.
Count risers, not treads: a riser is the vertical face between two treads, and a flight is the steps between landings. Four or more risers in one flight require a handrail on at least one side; both sides also comply.
On the job
Four is the line, and one side satisfies it — the exam tests both halves.
Exact wording
A handrail is required on at least one side of each flight of stairs with four or more risers.
Residential Code § r318.7.8
Install a guard if the drop exceeds 30 inches within 36 inches of the edge.
The requirement covers open-sided floors, stairs, ramps, and landings. Measure the 30 inches vertically at any point within 36 inches horizontally of the open edge, down to the floor or grade below. Insect screening is not a guard.
On the job
The trigger is measured within 36 inches of the edge, not at the edge — the slope rule the exam hides in the numbers.
Exact wording
Guards are required at open-sided walking surfaces — floors, stairs, ramps, and landings — located more than 30 inches above the floor or grade below, measured vertically at any point within 36 inches horizontally of the edge of the open side. Insect screening is not a guard.
Residential Code § r321.1.1
Build required guards at least 42 inches high. Stair guards may stop at 34 inches.
Measure guard height vertically above the walking surface, or above the line connecting the stair nosings, at open-sided stairs, porches, balconies, and landings. California requires at least 42 inches, not the lower height in other codes or older editions. On the open sides of stairs a guard may be as low as 34 inches from the nosing line, and where its top serves as the handrail, keep it between 34 and 38 inches from that line.
On the job
42 inches is California's number, higher than the model code's — a favorite exam distinction — with the 34-inch stair allowance as the qualifier.
Exact wording
Required guards at open-sided walking surfaces, including stairs, porches, balconies, and landings, must be at least 42 inches high, measured vertically above the walking surface or the line connecting the nosings. The exam tests California's number: a lower guard height remembered from another code or an older edition is the wrong answer here. Guards on the open sides of stairs may be at least 34 inches from the nosing line, and where the guard's top serves as the handrail it must be between 34 and 38 inches from that line.
Residential Code § r321.1.2
Guard openings must stop a 4-inch sphere. Open stair sides allow a 4-3/8-inch sphere.
Openings in a required guard count from the walking surface up to the required guard height; each must stop a 4-inch sphere. On the open sides of stairs the limit is a 4-3/8-inch sphere, and the triangular opening formed by the riser, tread, and bottom rail may not pass a 6-inch sphere.
On the job
4 inches is the tested figure; 4-3/8 and 6 are the stair exceptions the exam uses as distractors.
Exact wording
Required guards may not have openings from the walking surface to the required guard height that pass a 4-inch-diameter sphere. On the open sides of stairs the limit is a 4-3/8-inch sphere, and the triangular opening formed by the riser, tread, and bottom rail may not pass a 6-inch sphere.
Residential Code § r321.1.3
Measure total rise for a stairway from finished floor to finished floor.
If floor finishes go down after the stairs are built, add their thickness in — because riser height is measured between the surfaces people walk on, and the code allows only a small variation between risers in a flight.
On the job
A stair laid out subfloor to subfloor and then finished with tile below and hardwood above ends with two risers off by the finish thicknesses.
Exact wording
Total rise for a stairway is measured between the finished walking surfaces — finished floor at the bottom to finished floor at the top — with the thickness of any floor finishes laid after the stairs are built added in, because riser height is measured between the surfaces people walk on and the code allows only a small variation between risers in a flight.
Standard trade practice
Take away
6 rules · 2 minFraming arithmetic
Round the stair riser count up. Rounding down puts every riser over the maximum.
Divide the total rise by the maximum riser height allowed, then round up to the next whole riser. Divide the total rise by that count for the actual riser height. With 108 inches of total rise and a 7-3/4-inch (7.75) maximum: 108 ÷ 7.75 = 13.9, so 14 risers at 7.71 inches each.
On the job
Rounding down leaves every riser over the cap; the exam's stair problems turn on rounding the right direction.
Exact wording
To lay out a stair, divide the total rise by the maximum riser allowed and round UP to the next whole riser; then divide the total rise by that count for the actual riser height. For 108 inches of rise at a 7-3/4-inch cap: 108 ÷ 7.75 = 13.9, so 14 risers at 7.71 inches each.
Standard trade practice
A common rafter's line length is the hypotenuse of its rise and run.
On a gable roof, run is half the span, and rise is run × ( ÷ 12): line length is the square root of rise squared plus run squared. A 32-foot span at 9-in-12 gives run 16 feet, rise 12 feet, length 20 feet. Add overhang to the run when you work out the length to the fascia, but take the ridge-board deduction off at layout.
On the job
The exam gives span and slope and asks for length, or gives run and slope and asks for rise — the same triangle from three sides.
Exact wording
A common rafter's line length is the hypotenuse of its rise and run. Run is half the span on a gable roof; rise is run × (unit rise ÷ 12); length is the square root of rise squared plus run squared. A 32-foot span at 9-in-12: run 16 feet, rise 12 feet, length 20 feet. Overhang adds to the run when the length is figured to the fascia; the ridge-board deduction comes off at layout.
Standard trade practice
Calculate board feet from nominal thickness times nominal width times length in feet divided by 12.
Thickness and width are nominal inches — a 2x4 counts as a full 2 by 4 — and length is in feet. Divide by 12 per piece, then multiply by the piece count. Forty 2x6s at 10 feet are 400 board feet.
On the job
Nominal dimensions, not actual — the trap the exam sets in the numbers.
Exact wording
Board feet equal nominal thickness in inches × nominal width in inches × length in feet ÷ 12, per piece, times the piece count. Forty 2x6s at 10 feet are 400 board feet.
Standard trade practice
On a straight wall, add one stud to the number of spaces you count.
Spaces are the bays between studs. Convert the wall length to inches and divide by the on-center spacing for the number of spaces: 32 feet is 384 inches, 384 ÷ 16 = 24 spaces, so 25 layout studs. Corners, intersections, jacks, and cripples are counted on top.
On the job
The plus-one is what the exam checks; the extras are what a bid checks.
Exact wording
For a straight wall, convert the length to inches, divide by the on-center spacing for the number of spaces, and add one stud to close the run: 32 feet is 384 inches, 384 ÷ 16 = 24 spaces, 25 layout studs. Corners, intersections, jacks, and cripples are counted on top.
Standard trade practice
A hip rafter runs the diagonal of the square the common run makes.
The common run is the horizontal distance one common rafter covers, and it forms the side of a square. The hip crosses that square on the diagonal, so its horizontal run is the common run times the square root of two. Its line length is the hypotenuse of that diagonal run and the rise. Add overhang separately.
On the job
On a 24-foot building at 6 in 12, the common run is 12 feet, the hip run is 16.97 feet, and the hip is 18.00 feet long.
Exact wording
A hip rafter runs on the diagonal of the square formed by the common run, so its horizontal run is the common run times the square root of two, and its line length is the hypotenuse of that diagonal run and the rise; overhang is added separately.
Standard trade practice
You estimate stucco by the square yard.
Take the gross wall area in square feet, subtract the window and door openings, then divide by 9. That is your net square yards. Add any waste your estimate carries on top of that.
On the job
A 60-by-8 wall with two 3-by-4 windows and a 3-by-8 door is 432 net square feet, or 48 square yards.
Exact wording
Stucco is estimated by the square yard: gross wall area in square feet minus the openings, divided by 9, plus any waste the estimate carries.
Standard trade practice
Take away
Important numbers to know
Where people go wrong
Sounds right: " and are the same thing."
Where’s the catch?
Sounds right: "A ridge board carries the roof."
Where’s the catch?
Sounds right: "The 30-inch guard rule is measured at the edge of the deck."
Where’s the catch?
Sounds right: "A 36-inch guard is fine — that is what the model code says."
Where’s the catch?
Sounds right: " and draftstopping are the same material in the same places."
Where’s the catch?
Sounds right: "Any notch under half the joist depth is fine."
Where’s the catch?
Sounds right: "Round the riser count down so the stair has fewer steps."
Where’s the catch?
Sounds right: "A 40-percent hole in a bearing-wall stud is fine — 40 is under the 60-percent limit."
Where’s the catch?
Sounds right: "Board feet use the actual dressed size."
Where’s the catch?
Sounds right: "A cripple wall is never a story."
Where’s the catch?
Glossary
Every term this guide defines, in one place. Each is also defined where it first appears.
- Band joist
- The joist that closes the edge of the floor framing. A deck ledger fastens to it, so its size and material are limited.
- Braced wall panel
- A full-height section of wall built to resist in-plane shear through its framing, sheathing, and anchors.
- Collar tie
- A horizontal member in the upper third of the attic that ties opposing rafters together near the ridge.
- Draftstop
- A material that divides a large concealed floor-ceiling space into smaller ones so fire and smoke cannot travel the whole cavity.
- Fireblocking
- Material that cuts off concealed draft openings between spaces — at floor and ceiling lines, at soffits, and around pipes and ducts.
- Hold-down
- A connector that ties the end stud of a braced wall panel down to the foundation or the framing below, against uplift.
- Jack stud
- The shorter stud under each end of a header that carries the header's end down to the plate. Also called a trimmer.
- Plate washer
- A square steel washer under the anchor-bolt nut that spreads the load over the sill plate so the plate does not split.
- Rafter tie
- A horizontal member at the rafters' lower ends that keeps the walls from spreading when ceiling joists do not do that job.
- Ridge board vs. ridge beam
- A ridge board only connects opposing rafters. A ridge beam is structure: it carries the rafters' upper ends and needs support at each end.
- Seismic Design Category (SDC)
- A classification a building gets from its occupancy and the severity of the design earthquake at its site. D0 through D2 are the high-seismic categories most of California falls in.
- Unit rise
- The inches of rise for every 12 inches of run on a roof — the slope, written as 6-in-12 or 9-in-12.
- Water-resistive barrier (WRB)
- The building paper or wrap behind the exterior covering that keeps water off the sheathing and framing.
- Weep screed
- A perforated metal or plastic strip at the base of a stucco wall that stops the plaster and lets trapped water drain out.
Keep going
- Practice questions for General Building (B) — Framing and Structural Components is 20% of the exam.
- Job scenario: The Deck That Left the House
- Also in Framing and Structural Components: Framing and Structural Components: The Load Path, by the Book
- Every number on one page — this guide’s figures alongside every other General Building (B) guide’s.
Test yourself: 12 questions for this guide
A paid account adds more ways to practice and prepare: study questions after every chapter, practice questions for every topic, timed practice exams, and job scenarios drawn from real jobs. A free account gets you one timed practice exam and saves your progress across devices. Here is one of this guide's questions:
An electrician wants to bore a stud right where a plumber already notched it. Allowed?
AnswerNo. A bored hole may not be in the same section of the stud as a cut or notch, and its edge stays at least 5/8 inch from the stud's edge.
Residential Code § r602.6
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