Do Floor Joists Need To Be Treated

The joists were pressure treated lumber so i was surprised at how badly decayed they were.

Do floor joists need to be treated. The rim joist is 1 8in to 1 4in higher than the floor joists. In the past 2x4s or 2x6s were sometimes used as floor joists. Floor joists installed on second or third or higher levels double as ceiling joists for the level below. You can watch an informative video that shows a treated lumber sill plate and how it rests on a foundation.

Just click here sill plate video. But my friend wasn t. I m using a pt 2x12 for a rim joist with 2x12 floor joists. This size is no longer acceptable when framing a structure.

2 grade of douglas fir are indicated below. Should i shim the floor joists prior to the installation of the sub floor to even it up or just subfloor over it and keep framing because it will eventually shrink to the level of the floor joist. Maximum floor joist span for no. The extra two inches of vertical distance when a floor is framed with 2 x 10 joists rather than 2 x 12s can be quite important for example.

He sees it all the time. This treated lumber is bolted to the foundation and the floor joists typically rest on it. Dead load weight of structure and fixed loads 10 lbs ft 2. Common sense tells you that large floor joists can carry more load and spacing joists closer together also increases the load bearing capacity of a floor.

But larger is not always better when builders are constructing a home or adding a room addition. Deck joists rotting from the top edge down because the deck boards and debris keep them damp for weeks after rain. Since these come into direct contact with masonry they should be treated wood. If wind is a concern metal tie downs can also be added to keep the home anchored properly to the foundation.

1 psf lb f ft 2 47 88 n m 2. The allowable stresses of pt lumber are lower than non treated lumber which means it can not span as far. These problems must be addressed firsthand prior to implementing any restoration steps. The first piece of lumber commonly attached to the top of a house foundation is often called a sill plate.

Not treating the initial problem most often floor joists need to be sistered because of two problems either water damage which leads to rot or termite damage that crumbled the joist. Higher floors use something called a top plate instead of a sill plate that forms the outside structure for flooring joists on that level. Also pt lumber is corrosive so connections need to be such that they resist corrosion. In buildings with basements the first level of floor joists serves the same purpose.