New Floor Joists

You just have to make sure that the joists can handle the addition of more weight from the plywood subfloor and any additional floor coverings.

New floor joists. Nailing two 2x4s together will work to span about three joists unless the sag is under a weight bearing wall. Tack a beam under the sagging joists. Make sure you also buy the same type of joist. Find a new floor joist with these exact same dimensions.

If only a few joists are rotted primarily at the bottom they can be repaired using a process known as sistering after the rot is cleaned away and the timber treated to prevent more problems a new joist is laid beside the old one and fastened to it. 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. While it is a good idea to replace rotted material with 2x8s it may require some notching to fit between the sub floor and ledger board. The rim joist sits vertically on top of the sill plate along the outside of the frame to create a lip for the main floor joists.

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. Then set new joists same height as existing ones alongside the old. First renail the existing plywood subfloor so that the old nails are tight and add new nails to achieve a maximum nail spacing of 6 inches. A day until they re level.

Generally newer home floor joists are made from 2x8s or new engineered i beams older homes however may have 2x6s instead. Set a hydraulic jack and post under the beam and jack up the joists about 1 8 in. Joists are spaced at regular intervals much like the studs in a wall frame. How much repairing floor joists should cost.

Once you have done this you can replace or install your floorboards normally confident that you can rely on your joists to hold your floor together. You can also lay down new hardwood floor on the top side of the floor. Where floor joists are spaced 16 inches on center whether or not a 3 4 inch plywood subfloor is adequate for this type of installation is a judgment call. Repeat the process as many times as necessary to have joists at roughly 16 inch intervals underneath your floor.

But larger is not always better when builders are constructing a home or adding a room addition. They are covered with subflooring panels of plywood or oriented strandboard osb to complete the floor s structural assembly and create the solid continuous platform on which you install tile carpet or other finish flooring. Average costs and comments from costhelper s team of professional journalists and community of users. Step 5 finishing up.

Use a tape measure to measure the length width and height of your existing floor joist. Some plywood subfloors deflect more than others. For most jobs 2 in 5 1 cm x 10 in 25 cm boards are an ideal size. Find a replacement joist that is the same size as your floor joist.