how to properly attach ledger to t1-11siding

Old 09-02-14, 09:39 AM
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how to properly attach ledger to t1-11siding

Hey extending the deck on my house and need some advice on how to attach the ledger to my siding. I have t1-11 plywood siding. Behind the siding is foam and then the studs so there is no sheathing behind the t1-11. I was going to just put the ledger on the siding so it had a flat solid surface to be attached to. But then was thinking I should flash it. But if I cut out the bottom of siding then the ledger board would be going over the foam board and I'm worried the foam wouldn't be a solid surface for the ledger board to sit on but it would be properly flashed cuz I could then slide the flashing under the siding then over the ledger. I tried researching it and one guy asked the same thing but no one gave him an answer. He did have a couple more options being that you could use washers to keep the ledger a 1/2" off the siding so there is an air gap for drying or to just put the ledger board on the siding and caulk it a bunch. I'm trying to do it right the first time so if anyone could give me some advice it would be greatly appreciated
Old 09-02-14, 10:14 AM
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Galvanized steel flashing is mandatory. I'd cut the T1-11 and the foam backing so you can bolt your ledger to the rim joist of the house with the flashing in between and extending up under the T1-11.
Old 09-02-14, 11:41 AM
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Pilot Dane is 100% correct. Cut out both the foam and the siding and install the ledger directly onto the framing. Then slide a z-flashing under the siding to flash the ledger. You will likely want to add blocking between your joists later if you need to have a solid edge for flooring or an edge band to fasten to.

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