CARPENTRY STANDARDS – ROUGH
(Rough Carpentry, Lumber & Truss)
Framing or rough carpentry provides the skeletal structure which includes fabrication of wood portions of the floor systems, exterior walls, interior partitions and roof which are built on and supported by the foundation.
The exterior wall framing is designed to support the vertical load from the floors and roof and to resist lateral loads resulting from winds. Interior partitions may or may not be load bearing. The roof is designed to support its own weight plus that of anticipated loads from snow, ice and wind. The framing is quality controlled by the building code and subject to building inspection when the entire framed structure can be viewed.
Wood framing can be fabricated on or off a job site, or a combination of both. Even when most of the framing is done on site, there has been a trend to use pre-manufactured components, such as roof or floor trusses, in lieu of the more conventional joist and rafter construction. As a natural product, wood will respond to humidity and temperature conditions and can cause shrinking, twisting or warping of the framing material. Some of these conditions can be controlled or minimized; others are due to the nature of wood itself.
In single family construction, lumber type and grade, span, spacing and load bearing capacities are tightly controlled by code, while the carpentry foreman uses his own judgment in determining the exact layout. Hence, the accumulation of tolerances of several inches in overall dimension is not unusual.
Common Defects or Problems:
- Floors squeak
- Uneven or unlevel floors
- Crowned floor joist
- Seams or ridges appear in the resilient flooring due to subfloor irregularities
- Bowed walls
- Out of plumb walls
- Out of plumb windows or windows do not operate
- Truss lift
- Cracked trusses
- Bowed ceilings
1. Common Defect or Problem – Floors squeak.
Performance Standard – Floor squeaks are common to new construction and a squeak-proof floor cannot be guaranteed.
Builder Repair Responsibility – Builder should try to minimize the floor squeaks and must correct if caused by a construction defect. It should be noted that a second floor repair would be surface nailing in carpeted areas and impossible in vinyl or ceramic areas.
Craig’s Comments: While a 100% squeak-proof floor may be difficult to obtain or guarantee, many steps can be taken to virtually eliminate squeaks.
- Sheathing and underlayment should be fastened to joists per code and manufacturer specs.
- Construction adhesive should be applied to the top of each joist, per manufacturer specs.
- Screws can be used to attach the sheathing rather than nails.
- Engineered floor joists or trusses can be used rather than dimensional lumber.
- If diagonal metal bracing is used between joists, the bracing should be installed so as to not rub against each other.
2. Common Defect or Problem – Uneven or unlevel floors
Performance Standard – Floors shall not be more than ¼” out of plane or level in wood, vinyl and ceramic areas or ½” out of plane in carpeted areas within any 32″ measurement when measured parallel to the joists.
Builder Repair Responsibility – Builder to repair to meet performance standard.
Craig’s Comments: Floors should be no more than 1/8″ out of plane or level within a 32″ direction regardless of orientation to floor joists. A floor that is more than 1/8″ out of plane or level in 32″ will be obvious when walking across the floor and develop noticeable wear spots. Some causes of out of plane/level floors are crowned or cupped floor joists, improperly shimmed or supported beams, sagging floors due to an insufficient foundation, or an out-of-plane or out-of-level foundation.
3. Common Defect or Problem – Crowned floor joist.
Performance Standard – Floors shall not be more than ¼” out of plane or level in wood, vinyl and ceramic areas or ½” out of plane in carpeted areas within any 32″ measurement when measured parallel to the joists.
Builder Repair Responsibility – Builder to repair to meet performance standard
Craig’s Comments: See #2 above. Crowned floor joists can be corrected by cutting up into the joist from the bottom edge. This allows the joist to bend back in line with the other joists. Once this is done, another piece of wood needs to be attached to the sides of the cut joist to reestablish the structural abilities of the joist. See drawing.
4. Common Defect or Problem – Seams or ridges appear in the resilient flooring due to subfloor irregularities.
Performance Standard – In the natural settling and shrinkage process, some mismatch of the subfloor may exhibit and mirror itself as ridges or depressions showing on the surface goods. This can be minimized by the customer in his selection of an embossed pattern in a darker color. In particular, lighter solid colors and/or smooth vinyl surfaces mirror any minor variations of the subsurfaces to which they are applied and emphasize this ridging. If the ridge or depression effect exceeds 1/8″ and cannot be corrected from below, the resilient floor must be corrected. The ridge measurements should be made by measuring the gap created when a 6″ straight edge is placed tightly 3″on each side of the defect and the gap measured between the floor and the straight edge at the other end.
Builder Repair Responsibility – If ridges exceeds standard, builder to remove the sheet goods in the minimum area where the joint will not be readily visible when repaired, renail the subflooring, sand smooth and/or fill gap and replace the sheet goods. Owner should note that there may be a mismatch in materials due to time or dye lot variations. If the material is unavailable due to discontinuation, unless the owner will accept a repair with as closely matching materials as is currently available or correction by some other means, builder should credit the owner 1 ½” times the cost to repair if the material were available. This would be 1½ times the minimum service charge, plus the additional hourly labor charge and the material cost needed to make the repair.
Craig’s Comments: – Subfloor irregularities that show up in resilient flooring will cause premature darkening and/or wearing of the flooring. Improper preparation is a common cause of visible joints in subfloor materials, while settling and wood movement can cause ridges and grooves. Ridges or grooves should not be more than 1/16″ anywhere within 3″ of the ridge or groove. See diagram.
5. Common Defect or Problem – Bowed walls
Performance Standard – All interior and exterior walls have slight variances on their finished surfaces. Walls should not bow more than ¼” out of line within any 32″ horizontal or vertical measurement.
Builder Repair Responsibility – Builder will repair to meet performance standard.
Craig’s Comments: Bowed walls are difficult to fix once the house is completed. Furring out a new wall over the bowed wall is a viable option. Steps to prevent bowed walls in the first place are:
- Proper crowning and culling of studs when
building the wall. - The use of alternative wall materials, such
as steel studs, ICFs, SIPs, and engineered products.
6. Common Defect or Problem – Out of plumb walls
Performance Standard – Walls should not be more than ¼” out of plumb for any 32″ vertical measurement.
Builder Repair Responsibility – Builder will repair to meet performance standard.
Craig’s Comments: “Plumb” means perpendicular to the ground or to the floor. A plumb wall extends straight up, away from the center of the earth. Plumb is measured with the plumb vial on a construction level or with a string line and weight commonly called a plumb bob. Walls that are significantly out of plumb can affect door and window openings, cabinets and other materials or fixtures that connect to the walls. An out of plumb wall may be the result of improper plumbing of the wall during construction, improper fastening to adjoining walls or other support material (this could include too much weight or force on the wall pushing it out of plumb) or settlement in the building causing a wall to go out of plumb. Commonly available construction levels can plumb a wall to within ¼” at 8 feet. The SCRC Standards of ¼” in 32″ would be a total of ¾” in an 8 foot wall. Craig’s opinion is that this would probably not be noticeable in a wall with no windows, doors or cabinets, but would result in creative trim work in a wall with windows, doors or cabinetry. Therefore, Craig’s recommendations are a maximum out of plumb of ½” in 8 feet in walls with openings or cabinetry.
7. Common Defect or Problem – Out of plumb windows or windows do not operate.
Performance Standard – Windows must operate with reasonable ease as designed.
Builder Repair Responsibility – Builder to repair to be operable.
Craig’s Comments: Windows are often required for emergency exit. Windows that do not operate properly must be fixed. Out of plumb means that the sides are not straight up and down. According to this standard, a window could be installed at a 45 degree angle, and still be acceptable.
Common Defect or Problem – Truss lift
Performance Standard – Truss lift occurs during the heating season and normally returns back down in the summer months. Builder is not responsible for inadvertent cutting of tape where wallpapering may have been done.
Builder Repair Responsibility – This is to be corrected only during the summer months after the first heating season, only if first reported during year one. If the problem reoccurs in the next heating season, and gap exceeds 1″, then additional methods must be taken to correct the problem.
Craig’s comments: Truss lift is caused by differences in moisture content (and therefore size) of the top and bottom members of the roof trusses. (Excessive movement may indicate excessive moisture levels in the attic.) In the winter, the bottom members (chords) of a truss are usually warmer than the top chords because they are covered with insulation. Warmer air is usually dryer, so the bottom chords shrink compared to the top chords, and result in the center of the truss bowing upward away from the center walls. Flatter roof are more prone to truss lift that steeper roofs. (The opposite can happen in the summer, when the top chords are warmer and dryer than bottom chords. This causes the middle of the trusses to push downward on interior walls, and lift up at the outside walls.) This situation has been studied by truss manufacturers and others. Methods to minimize truss uplift are:
- Do not nail the truss to interior walls. Instead, use truss clips that allow the truss to flex without pushing or pulling on interior walls. (see diagram)
- Do not fasten ceiling drywall to the truss within 18 inches of an interior wall. Use drywall clips fastened to interior walls. This allows the drywall to bend slightly as the truss moves.
- Insulate the roof rather than the ceiling. This keeps the moisture content of the top and bottom chords more the same, and lessens the expansion or shrinkage differences.
Common Defect or Problem – Cracked trusses
Performance Standard – Builder to contact truss manufacturer to make sure truss conforms to its engineering.
Builder Repair Responsibility – Repair as per recommendation of truss manufacturer.
Craig’s Comments: Trusses are engineered products where each piece is designed to perform a specific function. A crack, break or cut in any piece of the truss may make the whole truss not capable of performing its function. Therefore, any crack, cut or break in a truss should be addressed per manufacturer or engineer’s recommendations.
10. Common Defect or Problem – Bowed ceilings
Performance Standard – All interior and exterior frame walls or ceilings have slight variations on the finished surfaces. Bowing should not be visible so as to detract from the finished surface. Ceilings, which are bowed more than ½ inch within a 36-inch measurement running parallel with ceiling joist, shall be excessive.
Builder Repair Responsibility – Ceiling bowed in excess of the performance standard shall be corrected.
Craig’s Comments: Some causes of bowed ceilings are bowed ceiling joists, too much weight in the space above, or beams in the ceiling that are not built properly or are not functioning properly. A ceiling with a SC RCS acceptable ½” bow in 36″ would sag one inch across a 12 ft room. Building Codes require that ceiling joists not sag (deflect) more than 1/240 of their length, which in a 12 ft room would be no more than 0.6 inches. If a floor is located above the ceiling, the sag is limited to 1/360 of the length, or 0.4 inches. So if the sag is confined to one spot, it may be fixable by addressing a joist or two in the area. If the sag is consistent from the wall to the center of the room, the cause may be a structural problem.
