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Common Wood Framing Errors

Wood framing mistakes can be avoided

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wood framing

Wood framing design.

Photo Courtesy of Darren Moore Darren's Photos

Common Wood Framing Errors

Wood framing errors are really common within the construction industry and for decades some contractors have been using wood as their main construction material. They use it for numerous reasons, but most of all they think that it is easy to install and that almost everyone can handle it.

Wood Floor Designs

Floor designs are mainly framing errors that present when using engineered wood with dimension lumber. Structural wood may have different dimensions than dimension lumber. This kind of wood can shrink due to numerous reasons and could soften or weaken your structure. Another common mistake is to skip the required spacing in the joist, causing soft spots or vulnerable areas that will reduce load transfer to all wood components. If you need, for some reason, to change the spacing, consult the design engineer that he will be able to provide a new design for whatever reason you might have.

Wood Underlayment

Another common mistake is to avoid sanded underlayment when using glued finished flooring materials. These panels usually beaten by the construction process, might present their grain to the surface if they are not properly sanded. Some other imperfections will probably get to the surface on thin floor materials, but they are not required if you are going to use thicker flooring material, such as carpets. Look for the word ‘underlayment’ near the trademark of the panel to get sure that you are using the correct panel and avoid indentations that can arise in floor coverings.

Moisture can also present additional problems. Normally, there are a lot contractors who use the attic as an area where they can accumulate the vapor. Sometimes all exhaust ducts are leading that way, and vapor accumulates and then transforms into moisture. It will act upon the wood, connectors and plates, reducing their capacity to transfer the loads and then finally collapse. Also the roof appearance will decay and moisture will get to the outside causing another type of problem.

Leveling a Wood Floor

Another common mistake is not leveling out the wood framing members. Smaller differences such as ¼” will result in an appearance of roller coaster look alike floor. Level the framing members using a string level and a string from side to side, to check for dips and unlevel spots on the frame. Also double check the walls and the roof to avoid unlevel surfaces.

I-joist cutting present another problem for weak spots and reducing load capacity from the joist. It is a common practice to just cut anywhere to install wiring and plumbing lines in the joist, reducing the area of the joist and creating weak spots. Normally, joists has pre-cut areas where you can install the rough-in, and that was already taken into consideration when the design was made.

Another common mistake is the improper end support and incorrect height of beam pockets. Glulam beams are specific design products to use in a structure. These wood beams should be used in bearing for the transfer of loads. Also avoid unusual joint details and placing beams in direct contact with concrete or masonry, since they can interact and get moisture from one another.

Wood Window Headers

When creating headers for windows do not add additional wood just because you think that it will strengthen the area. If the opening is greater than 4’, use glulam beam into bearing. The joists will be attached to the framing member and the weight of the floor will be supported properly over the window, preventing a broken window in the future.

Glue and adhesive spread should be used carefully, following manufacturer instructions. A hot humid day of summer will not be the same as a winter condition, and sometimes the glue is overexposed to atmospheric conditions resulting on improper performance. Avoid nailing after the glue has been applied and clean the surface prior to glue application. The use of adhesive on wall and roof panels is not recommended because they need room to expand and contract with the changing atmosphere.

Finally, allow space and gaps for wood to expand and contract. Every wood will have tolerances depending on their use and don’t leave nails that miss the framing. Humidity and other factors might tend to bend the wood if they are not installed leaving a gap at the end, usually it can be 1/8”.

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