Sistering Joists

Looking up at this floor joist, it's clear it will need some added support.

Two things about "sistering." First, it has nothing to do with your family and second, it's a relatively difficult job, not something for the weekend do-it-yourselfer. Sistering is securing a strong, new piece of lumber to a floor joist that's in trouble. The floor could be squeaking, or too springy. The joist might be cracked or sagging. Or, it may have been damaged by rot or termites.

Depending on its purpose, a sister can run the length of the joist, or it might just be a few feet long. It can be secured to the old joist with nails or screws, or even bolts. And if the joist is sagging, it may need to be jacked up before the sister is attached. As you can see, it can be complicated.

In most cases, it's a job for a professional. Look for a licensed contractor, who's insured and bonded. Get three estimates in writing. And make sure you're comparing apples to apples. The estimates should cover the same work. Once the job is done, you’ll have a floor that's long-lasting and solid beneath your feet.

Guests
Jack Reilly
Building inspector
2219 East Pratt St.
Baltimore, MD 21231
Phone: 410-276-6444
Also in this Episode

House Detective : Episode HDT-413
•	Sistering Joists
•	Sealing Concrete