Fix Slanted Floor Joist With Sistering

On the top side of the floor another fix it idea to lay down new hardwood over the existing floor.

Fix slanted floor joist with sistering.

My plan is to use construction adhesive and tack it into place with nails. Termites leave telltale mud tunnels on foundations and posts. You will have to make sure your joists can handle the addition of considerably more weight from the plywood subfloor and any floor coverings. Doing so strengthens weak joists and can help straighten sagging joists.

However doing this does not fix the slant that the floor has taken since the old joists got damaged. Powderpost beetles leave joists and beams filled with small holes and carpenter ants make their appearance at the first sign of warm weather in the spring. When a joist is sistered a healthy board is run parallel and attached to the faulty one to transfer the load. A thumbtack pro with experience in subfloor repairs in alexandria virginia charges a flat labor fee of 175 for 50 square feet or more of floor repair with an additional charge to remove hardwood floors that have been glued down.

To permenantly secure the joist i will use 1 2 inch carriage bolts in sets. A plywood subfloor will bridge any minor waves in the existing floor and leveling compound would help too. Nailing two 2x4s together will work to span about three joists unless the sag is under a weight bearing wall. Then set new joists same height as existing ones alongside the old.

Framing lumber is the typical. I am going to sister this joist with an identical sized joist 2x10 over its full length. Replacing joists costs around 100 to 300 for each new joist. Set a hydraulic jack and post under the beam and jack up the joists about 1 8 in.

How to sister a floor joist. Any advice about fixing techniques to attach the new joists. Tack a beam under the sagging joists. Deteriorating floor joists or posts.

The most common way joists are repaired is to sister it up. Removing the joists entirely would cause damage to the subfloor and possibly to your flooring itself. The original joists look to be very good but since they are probably at least 50 years old and i want to have a good flat floor i am planning to use the sistering method. Essentially sliding a whole member beside it and nail the heck out of it from both sides with a lot of nails.

Sistering floor joists costs 8 12 per foot. If the new sister bears on wood at least 1 5 on each end then you re good to go. When you fix your moisture problems this will fix your sloping floor issue. Plus this is a stone house and so joists are fixed directly into external walls in pockets.

In situations when sistering damaged floor joists with lumber of similar dimensions it can be easy to notch and slide the sister board into place. A day until they re level.