Floor Joist Leveling By Sistering

Sistering is a.

Floor joist leveling by sistering.

The amount of weight that each floor joist handles is pretty amazing. Our 60 year old floor joists are showing their age. You will have to make sure your joists can handle the addition of considerably more weight from the plywood subfloor and any floor coverings. A plywood subfloor will bridge any minor waves in the existing floor and leveling compound would help too.

Then sister the joists will lvl joists at exactly the level you want. I forgot to mention the construction adhesive in between them. But it s usually best to run the sister joist over the entire span. This job can run you 1 000 and 5 000 depending on the extent of the job.

How to sister a floor joist. To permenantly secure the joist i will use 1 2 inch carriage bolts in sets. Then attach the sister joist using three 16d common nails driven every 16 in. It is important to jack this end level to keep the floor from sagging any more and to keep the joists from splintering later.

My plan is to use construction adhesive and tack it into place with nails. I am going to sister this joist with an identical sized joist 2x10 over its full length. Doing so strengthens weak joists and can help straighten sagging joists. Now that said when you have a major humpy floor you should bite the bullet and remove the subfloor planks down to the joists.

When sistering these pieces together it is easy to put just a few nails in the boards and move on. If you have an uneven floor you may need to think about leveling floor joists with shims. Driving 16d common nails in old hard wood is difficult. Lay a new 3 4 plywood subfloor and bob s your uncle.

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. When the sagging joists are level apply a generous bead of construction adhesive to the existing joist. On the top side of the floor another fix it idea to lay down new hardwood over the existing floor.

You will have a level sound surface to lay your new floor on. Framing lumber is the typical.