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Floor Joist Repair

Repair wood rot and broken floor joists in your home's foundation.

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Floor joists and band sills play a vital role in the construction of your house. Wooden floor joists can be found running parallel to each other at regular intervals along your house on top of band sills. But because they’re made of wood, if they’re exposed to water and moisture, they can rot or grow mold.

Popular Mechanics strongly urges that if the floor joists have rotted to a point at which they no longer provide adequate structural support, you should have them replaced. You can also reinforce or ‘sister’ joists, meaning fastening another joist to the rotted one’s side, but if you have a moisture problem in the area, this probably won’t help. The sister joist will eventually rot as well, and coating the joists with a surface treatment may slow the problem, but won’t solve it.


Foundation Systems of Michigan can reinforce or replace wooden floor joists and address the moisture problem as well with our VaporLoc EliteĀ® crawl space encapsulation system.

According to the University of Illinois Small Homes Council, as much as 18 gallons of water per day can evaporate into a crawlspace under a 1000-sq.-ft, house. So even if your dirt crawl space seems dry and dusty, the soil can still be pulling in moisture that can rot wood floor joists.

And why stop there? Get to the root of moisture problems in your home. Once you replace the rotten wood floor joists and band sills, you must find where the water came from in the first place so that it doesn’t continue to rot wood in your home.

If the leak problem is in your crawl space, our VaporLoc EliteĀ® crawl space liner can help keep your home separated from ground moisture. We can also help with basement waterproofing needs in Michigan.

Ask the Builder’s Tim Carter explains that the strength of wood floor joists is a function of the thickness of the joist, its height, wood type, and the distance between supports. If your floor’s support system is weak, it could feel like you’re walking across a trampoline!

Mold Spores on beams

Don’t go another day with rotten wood floor joists and band sills! We can replace them in your cities like Ann Arbor, Saginaw, Traverse City, Grand Rapids, Kalamazoo, Jackson, Muskegon, Lansing, Battle Creek, Toledo and throughout Michigan and Northern Ohio. Get your free quote today!

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Proudly Serving Northern, Central and Southeastern Michigan & Northern Ohio

Grand Rapids Office

5985 Clay Avenue SW
Grand Rapids, MI 49548

Livonia Headquarters

32985 Schoolcraft Road
Livonia, MI 48150

Traverse City Office

3805 Elmers Industrial Drive
Traverse City, MI 49685