I’ve run into a situation thats new to me, and wanted some advise. We are installing a kitchen in a three story condo slose to the beach. The kitchen is on the third floor, and has a boxed out window over the sink. Directly above the window is a balcony off of a bedroom. The condo’s were built with TJI’s, but hte balcony was built by cantilevering treated 2×10’s along side the I joists. There is a 6′ slider that leads to the balcony. THe problem is that water is entering along side the cantileverd joists and running down the inside wall. Whats the best way to flash the cantilevered joists? Currently there is no flashing other than a single angled peice that starts below the slider, and bends out over top of the joits approximately 2-3 inches. Someone siliconded along the edges of the joists where the blocking meets in an effort to stop the water, but hasn’t been effective.
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Try removing the silicone and use Geocel 2300 in its place. It works!
This is one of those things you would never think of unless you've seen it before, unfortunetly it isn't easy to fix after the fact. In new construction, a saw kerf angled out will help send the water back out, kerfs & caulking will help doubled joists where capilary action pulls the water in, only real solution now is flashing on top and over the joists and solid, sloped deck sheeting.
That sounds interesting. Could you explain that better or draw it?
"May the forces of evil be confused on the way to your house." -George Carlin
I'll try to explain it a little better. It's a row home type situation that is approximately 5 years old. They were poorly built, with very minimal flashing. The exterior finish is vertical soffit material that obviously only covers 12'. There are double "J" channel bands at 12' and 24' from the grade. (I wish I had a picture of this.). Anyway, the floor joists are 11 7/8" TJI's. There is a 6' wide by 4' deep balcony on the third floor. It's 5/4"x6" decking on 2x10's that are canteleverd 4', and extend into the building approximately 12 1/2'. There is no rim joists in this 6' section. Instead, the 2x10's are nailed into the bottom chord of the TJI's, and blocking is installed between the deck joists. This creates a situation where the sliding door on the third floor is approximately 2" above teh level of the decking. The only flashing is a piece of aluminum that is nailed to the sheathing under the door sill and bent out approximately 3" onto the deck joists. No flashing around the door or under the sill. They had a different contractor come out to repair the leak, and his answer was silicone, and lots of it. HE caulked the "J" channel to the door, and between teh blocking. IT didn't work though. Now we are installing a kitchen directly under where the deck is leaking, and we won't put things back together until this is fixed. The home owner is calling people to fix it, but that could take a while, and we would like to just do it and move on.
In addition to my previous suggestion, a shallow saw kerf on the bottom of the joists directly outside would also help.
second what GRCourter said. Silicone isn't a very good caulking for a lot of situations. It doesn't adhere well to many materials. There are much better performing caulks out there.
It is a poor design to start with so you are pretty well stuck with gobs of caulk to be renewed every year or two.
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if the balcony doesnt extend too far out, cut down the top of the joists about 1" so that a flashing can turn down properly, then re-deck. Or double up the 2x10 and cut both of them down. You are still going to get some water wicking back into the 2x10, so some type of decking that wouldn't let too much water through would be helpfull
I think I'd run a rubber membrane between the wall and the joist all around, lapping each by several inches, and being sure to get a tight seal to the joist. Cover the membrane with flashing to protect it.