Carpenter Ant Damage to Rim Joist

[Atilla the Hun]

I am in the process of purchasing a home that has severe carpenter ant damage on a 10 foot section of a rim joist that is sitting on a pressure treated sill plate. The rim joist backs onto a concrete stoop.

How would one properly repair this condition? Would the only suitable solution be to replace the damaged section of the joist or can sister boards be attached between each of the floor joists to effect the repair?

Does a rim joist support any weight bearing walls?

You can see pictures of the damage at

Any assistance would be greatly appreciated as I will close on the house this week.

[John Keiser]

Looks like some water damage, too.

Here in Hawaii, carpenter ants are more of a bother than a structural danger. I'd be more concerned with the visible water damage.

-- Remove -NOSPAM- to contact me.

[Rich]

Atilla the Hun, decides to chip in.

What are you going to sister to? I'd look into replacing the joist. Looks like the joist supports the outside wall which would definitely be a load bearing wall. Did you get an inspection on this house and is the ant problem taken care of? Looks like water problem too. I'd have an inspector or engineer look at this before I closed, and or get an estimate from a contractor and deduct it from the homes purchase price. This could be a very expensive proposition!

Rich

[RamblinOn]

Carpenter ants don't do a lot of damage. They move in after water and/or termites have done the damage.

[Randd01]

The rim joist holds the floorjoists up straight. The wall is also sitting ontop of it. Here is the way I replace them. I get small wooden 6X6 inch beam about 12 ft long. From inside the house if the basment has finished ceilings I put towels over the top of it to protect finished ceilings. Get two screw jacks from Home Depot and raise them just enought to take the weight off the rim joist no more then a quarter of an inch. Then go outside remove the siding and plywood to get at rim joist. Remove damaged section and replace with new joist. You will need a sawsall to cut the nails from the plywood floor thats is on top of it. It's really not that hard of a job but you will need a helper to position beam. Make sure you get an exterminator in to get rid of the ants. Also make sure you have at least 8 inches between sill and ground if that is possible. Some poeple put sheet metal underground to prevent termites from getting to wood. Good Luck