How To Replace And Level Floor Joists

Levelling floor joists how to level an old floor.

How to replace and level floor joists.

This job can run you 1 000 and 5 000 depending on the extent of the job. 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. If the uneven floor is due to floor joists that have warped or twisted over time or were incorrectly installed the only way to level the floor is to remove the subflooring and shim the joists. Nailing two 2x4s together will work to span about three joists unless the sag is under a weight bearing wall.

In order to see the joists without ripping up the floor you ll need to access them from a crawlspace or an unfinished basement. 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. Generally newer home floor joists are made from 2x8s or new engineered i beams older homes however may have 2x6s instead. Floor joists and posts support the flooring and damage to them is the most common cause of a sagging floor.

A good look at the floor joists will also help you determine if any need to be replaced. Deteriorating floor joists or posts. How much repairing floor joists should cost. Set a hydraulic jack and post under the beam and jack up the joists about 1 8 in.

Inspect the floor joists beneath the sagging or bowing area of the floor for any signs of damage. Jacking them up too fast may cause cracks in the walls and floors overhead. You will have to make sure your joists can handle the addition of considerably more weight from the plywood subfloor and any floor coverings. Make sure you also buy the same type of joist.

Replacing joists costs around 100 to 300 for each new joist. Find a replacement joist that is the same size as your floor joist. Average costs and comments from costhelper s team of professional journalists and community of users. On the top side of the floor another fix it idea to lay down new hardwood over the existing floor.

We show you how to lay floor boards over the leveled joists how to cut the floor boards to the right shape and how to use a chalk line. If your floor joist is an i joist for example buy an i joist. Deteriorating floor joists posts or beams can be caused by termite infestation water damage or dry rot. Leveling the floor with shims is when you attach thin wedge shaped pieces of wood on top of the low areas of the joists to make the top joists even.

A plywood subfloor will bridge any minor waves in the existing floor and leveling compound would help too. Use a tape measure to measure the length width and height of your existing floor joist. If you have an uneven floor you may need to think about leveling floor joists with shims. A day until they re level.