Floor Joist Leveling By Sistering

This job can run you 1 000 and 5 000 depending on the extent of the job.

Floor joist leveling by sistering.

Lay a new 3 4 plywood subfloor and bob s your uncle. The amount of weight that each floor joist handles is pretty amazing. Driving 16d common nails in old hard wood is difficult. Sistering joists means beefing them up with additional material.

I have a floor joist that i noticed has several large knots that have split vertically through the joist. You will have to make sure your joists can handle the addition of considerably more weight from the plywood subfloor and any floor coverings. I am going to sister this joist with an identical sized joist 2x10 over its full length. If you have an uneven floor you may need to think about leveling floor joists with shims.

It is important to jack this end level to keep the floor from sagging any more and to keep the joists from splintering later. But it s usually best to run the sister joist over the entire span. Our 60 year old floor joists are showing their age. 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.

Framing lumber is the typical. My plan is to use construction adhesive and tack it into place with nails. When the sagging joists are level apply a generous bead of construction adhesive to the existing joist. A plywood subfloor will bridge any minor waves in the existing floor and leveling compound would help too.

To permenantly secure the joist i will use 1 2 inch carriage bolts in sets. When sistering these pieces together it is easy to put just a few nails in the boards and move on. Sistering joists is a job for the pros who will bolt the new joists to the old joists and position the ends of the joists on the same sill plate that supports the original joists. How to sister a floor joist.

Here s how we are correcting the problems. Now that said when you have a major humpy floor you should bite the bullet and remove the subfloor planks down to the joists. Doing so strengthens weak joists and can help straighten sagging joists. I forgot to mention the construction adhesive in between them.

Sistering is a. You will have a level sound surface to lay your new floor on.