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Wood Framing
Wall and Ceiling Framing
Question | Answer |
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Name the five (5) systems used for wood frame construction. | a) western platform framing b) balloon framing c) post and beam d) pole frame e) structural insulated panels |
What is the distinguishing feature of western platform framing? | Floors and walls are constructed separately, with the completed floor becoming the working platform. |
What acts as firestops in platform framing? | wall plates |
What is the disadvantage of using solid lumber joists in platform framing? | Shrinkage occurs in the width of the floor joists. |
In balloon framing, how high do the wall studs extend in a two-storey building? | Each stud is toenailed to the sill plate and is continuous from the sill plate to the roof rafters. |
How are floors supported in balloon framing? | The main floor rests on the foundation mud sill. Upper floors are nailed to the side of studs and rest on a let in ribbon. |
What is the major advantage of balloon framing? | Fewer problems associated with shrinkage. |
Why can framing members in post and beam construction be spaced further apart? | Larger framing members can carry larger loads. |
Why is thicker roof sheathing required for post and beam construction? | Roof framing is spaced farther apart, so thicker sheathing is needed to reduce deflection. |
What is the interior and exterior finish attached to in post and beam construction? | Stud walls are erected between posts to create backing for interior and exterior finishes. |
What function do the poles serve in pole construction? | The poles act as the building foundation. |
What is the maximum allowable moisture content for framing lumber? | 19%. |
In the platform system, which framing member is used to support loads that occur over openings in walls? | Lintels |
In balloon framing, how are roof and floor loads transferred to the foundation? | Roof loads transfer to wall studs. Upper storey floor loads transfer to the studs by a let-in ribbon. The studs then transfer the loads to the foundation. |
What factors are used to determine the minimum allowable stud size for a building? | supported load, stud spacing, interior or exterior wall height, unsupported height |
What is the purpose of trimmer or jack studs? | carry the load from the lintel to the foundation |
What is the minimum end bearing for a lintel? | 38mm |
Where are cripple studs placed in a wall frame? | above and below wall openings. |
What is commonly used to provide anchorage and backing where two walls intersect? | L stud, U stud or ladder |
Blueprints show a section view of a conventionally framed wall. The ceiling height is 97 1/8" What length of stud is needed? | 97 1/8 - 3 wall plates (4 1/2) = 92 5/8 |
If there are irregularities in the floor frame, how far may the wall plates overhang the floor? | 1/3 the width of the plate |
Why is it desirable to have the wall studs occur directly over the floor joists? | better load transfer and eliminates problems for sub trades |
Why are door and window rough openings larger than the finished size? | insulation and leveling |
What is the first step in laying out rough openings? | find the centre |
What determines the length of the trimmer? | the height between the bottom plate to lintel |
What determines the length of the rough sill? | the width of the R/O |
What are two alternatives to an L post where a partition intersects a wall? | a) u post b) ladder |
If wall studs are laid out 16" o.c, what is the measurement to the edge of the first stud? | 15 3/4" |
When laying out regular studs, what must be done where a rough opening occurs? | mark out studs that fall in R/O as cripples |
According to the National Building Code, what length and quantity of nails are needed to end nail wall plates and studs together? | 2 nails, 82mm long |
When assembling the wall frame, what is done to the studs prior to placing them? | crown the studs up |
What is usually done with cap plates at corners and partition intersections? | cap plates are lapped |
Once the wall frame is assembled, what must be done before sheathing is applied? | wall must be squared to eliminate racking |
How is sheathing started if a long side wall is framed first? | sheathing must be flush |
On short side walls, the sheathing should project past the framing by how much? | sheathing should project the thickness of the wall |
What is the nailing pattern for applying wall sheathing? | 150 o.c spacing for edges and 300 o.c spacing in the field |
After an exterior wall is erected, what is done to the sole plate? | align w/chalk line start from one end and straighten |
What are some distinguishing features of a rake wall? | sloped top plate and studs cut at an angle |
When building interior walls, what problem may result if all the short partitions are erected first? | no or little space left for long walls |
What is a non-loadbearing partition? | supports no load other than itself |
If a non-loadbearing wall runs parallel to the floor joists, how must it be supported? | blocking every 1.2 meters or another joist running under the wall |
If the partitions have an insulated ceiling above them what must be placed between the top and cap plates during assembly? | 400mm strip of polyethylene |
What method is used to straighten the top wall? | string line and feeler blocks |
What is the best way to secure the bottoms of wall braces? | nail a block to the floor joists |
If a stud in a load bearing wall must be notched, how much solid lumber must be left? | at least 2/3 the width of the framing member must be intact |
Why would a plumbing wall be constructed out of 2X6 rather than 2X4 studs? | to accommodate plumbing drains and vent stacks |
What may be used to provide anchorage for a stair handrail? | backing or blocking |
What is a girth? | a framing member used to stiffen walls (ie. blocking) |
When framing walls, what consideration must be made for the application of drywall? | sufficient backing |
Why is a 400mm strip of polyethylene placed between the top and cap plates and the exterior wall partitions? | continuous vapor barrier |
What is the main purpose of ceiling joists? | tie exterior walls together and resist outward pressure |
How should ceiling joists be fastened to the wall plates? | 2 toe nails, 82mm long |
Identify three ways in which ceiling joists can meet on top of an interior bearing wall. | a) butted and cleated b) lapped c) lapped w/blocking between |
How is joist layout affected when joists are lapped over an interior wall? | on center spacing is offset |
What must be done to the outside ends of ceiling joists? | ends must be cut 10mm shy of rafters @ the same angle |
What are stub joists? | perpendicular ceiling framing members used in place of the end joist where hip rafters interfere with standard layout |
According to the National Building Code, what is the minimum size of an attic access required in a single family home? | 0.32m² no side shorter than 500mm |
What must be done to the joists if an opening in the ceiling is wider than two joist spaces? | must be doubled on either side of the opening |
Where would a flush beam be required? | in open areas where there is no bearing for a load |
What is a strongback? | 2x4 and 2x6 fastened together to form an L that runs perpendicular to joists, reducing deflection and maintaining set spacing |
When can a single top plate be used? | joists or rafters bear directly over or within 50mm of the edge of wall studs |
In a load bearing wall, what is used when there is a joint in a single top plate? | metal strap or plate at least 75mm x 150mm |
What is the maximum set spacing allowable by code? | 24" o.c |
Up to how much shrinkage is to be expected per floor in platform framing? | 12mm |
What is a common material used for roof sheathing in post and beam construction? | 1 1/2" tongue and groove |
Two methods for pole construction. | a) cut poles at elevation of the floor b) leave the poles full length |
What are some components of a structurally insulated panel system? | OSB, polyurethane, framing, interior skin (thermal barrier) |
Where does the most shrinkage occur in lumber? | across the width, then the thickness |
Studs used for loadbearing walls must be at least what grade? | Stud, Standard or No.2 |
Studs used for non-loadbearing walls may be what grade? | Stud, Utility or No.3 |
What is the difference in load transfer when using trusses compared to convention lumber? | truss systems often transfer all loads to the exterior walls and have a larger span, conventional lumber has a smaller span which increases the number of interior partitions |
What is a major problem in platform framing in high wind or earthquake prone areas? | pony walls have very little resistance to lateral loads which can create a hinge effect |
On load bearing walls, if no sheathing is used or does not provide lateral support, what additional support is required? | let in bracing, running 45 degrees from top of wall to bottom of stud, at least 1x4 material |
What is the purpose of a cap plate? | extra lateral strength and allow rafters to transfer loads with minimal deflection |
What is the minimum stud size? | 2X3 |
When the span of a lintel is over 3m, how much bearing does each end need? | 76mm |
What direction are walls typically laid out from? | left to right from the street view |
When constructing a ladder to receive a partition wall, what is the minimum spacing of each framing member? | min. 600mm o.c |
How big is the gap left between rows of wall sheathing? | 2mm |
How should a wall be fastened to the floor system in platform framing? | 82mm nails at least 400mm o.c fastened into joists or blocking |
How far can a loadbearing wall that carries only framed ceiling loads be from it's support below? | 900mm |
How far can a loadbearing wall supporting a floor load be from it's support? | 600mm |
How much material can be left after notching or drilling into a non loadbearing stud? | 40mm |
What framing member sits directly above the wall studs? | rafter or truss |
What framing member sits adjacent to the wall studs? | ceiling joist |