I have a 100 year old house with stone foundations. I'm in the process of re-parging the basement walls and found the ends of two of the joists to be completly rotted. The floor above is quite solid and there is no sign of movement or weakness anywhere. What do I need to do to repair and prevent future problems. I'm concerned about the estetics as well.
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If you have access to the joists from under the floor, it should be a fairly easy task to install a new joist along-side of the existing one then cut back the existing joist to eliminate the rotted end. Your old joists will be actual dimension lumber and you will be buying nominal lumber which will probably not be as wide or thick. Just be sure to rest the new joist on the sill plate, then attach the joist (sister) along the length of the joist nailing in a staggered pattern at 6-inch interval. The old joist will continue to carry the floor load, and the new joist will transfer that load to the sill plates.
Since there is no sagging, you don't need to do anything very elaborate. The final appearance will look like a doubled joist. You can even replace the section you cut out with a short length of 2x10 (or whatever size you are using). It might be easier to cut out the rot before you install the new joist, just be sure to provide temporary support to the joist until it is secured to the new sister.
Since there is no sagging, you don't need to do anything very elaborate. The final appearance will look like a doubled joist. You can even replace the section you cut out with a short length of 2x10 (or whatever size you are using). It might be easier to cut out the rot before you install the new joist, just be sure to provide temporary support to the joist until it is secured to the new sister.
Thanks. The joist was resting on the stone wall. Do I need to worry about any treatment of the wood to stop the rot?
Leak from the roof let water flow down to foundation. A contractor fixed up the rotten joists.
Be sure you've stopped leak that caused rot.
He used 4x4 across several joists and a couple jacks adjustable columns to lift and ease weight on joist ends. Cut out the rotten wood. Lined area with heavy 6 mil plastic. Replaced rotten sill plate and rotten rim (or ring) joist with pressure treated lumber. Add sister joists 4 to 5 ft long with construction glue and 3 inch screws.
You can use the heavy plastic, a hardiplank type board, or maybe the blue foam that is laid under stud walls to seperate the joist from the stone. Just use something waterproof that can take the weight.
One problem I've had is that the repair has bound the sliding door above the repair. As the treated lumber dries and shrinks and settles, the door is loosening.
Be sure you've stopped leak that caused rot.
He used 4x4 across several joists and a couple jacks adjustable columns to lift and ease weight on joist ends. Cut out the rotten wood. Lined area with heavy 6 mil plastic. Replaced rotten sill plate and rotten rim (or ring) joist with pressure treated lumber. Add sister joists 4 to 5 ft long with construction glue and 3 inch screws.
You can use the heavy plastic, a hardiplank type board, or maybe the blue foam that is laid under stud walls to seperate the joist from the stone. Just use something waterproof that can take the weight.
One problem I've had is that the repair has bound the sliding door above the repair. As the treated lumber dries and shrinks and settles, the door is loosening.















