Will Sistering a Joist Fix My Floor and Wall Gap?

Many homeowners know about sistering a floor joist to stabilize it, so it’s the go-to DIY solution when floor joists begin to fail. However, this is less of an actual solution and more of a band-aid. Not only does sistering not help with anything, but also it doesn’t fix the gap between the floor and the wall. 

What Sistering Does and Cannot Do 

Sistering a floor joist involves attaching a healthy wooden beam next to the one that is failing. Usually, the new beam is attached with a strong builder’s adhesive, though it is sometimes done with nails as well. The idea behind sistering a joist is to provide the damaged wood some aid so that the floor is stabilized. This is where the name “sistering” comes from, since the old wood is given a “sibling” beam for support. 

However, if you’re wondering if sistering a floor joist can repair the gap between your baseboard and your floor, it cannot. Sistering a joist only stabilizes and provides the floor with a certain amount of stability that cannot be provided by the failing joist. It cannot raise your floor to the point where the floor is even again and the gap is sealed. 

What You Can Do Instead 

Instead of sistering, you should contact your local foundation experts for an inspection. They will be able to determine what is causing the gaps to form and what needs to be done to repair your foundation. A proper foundation repair method will not only be able to stabilize your home and prevent further floor sagging, but also it can level your floor and closing the gap between the wall and floor.