Flashing 1st deck board, and lap siding
I normally work in a shop, but sometimes take outside jobs. I have some friends who ask me to build them a new deck.
I just tore off the old deck where the deck was fastened through the lap siding, with no flashing to keep the crud which gets trapped in that gap from rotting not just the deck framing, but the house floor framing.
In my checkered past, when I built decks, I would always flash out from behind the siding, out over the deck band-joist, but then hide most of the flashing behind the first deck board, which still leaves a place for crud to get trapped, even though the house is protected, that first deck board is going to be left compromised by the crud trap.
Do any of you have any solutions to this problem? I was thinking of using a wider/taller band joist, with the top front edge level with the deck surface maybe then sloping down and out at a 45º. Then starting the first deck board with a space out from there, where the crud would have a way to flow through.
Do any of you have any advice that you would care to share?
Replies
keith
You might want to try shellbuilder's idea.
http://forums.taunton.com/tp-breaktime/messages?msg=113816.15
Rich
One option would involve installing spacers behind your ledger board.
Flash the wall using metal and/or peel and stick membrane. Temporarily level and mount your ledger overtop the flashed area. Drill holes thru your ledger at your desired locations, but do not bolt. Now remove ledger and set face down.
Rip some strips of treated 2x approx 2-1/4 inches wide and cut these the same length as your ledger board's width, minus 1/2 inch. Bevel cut the tops of these strips to facilitate water run-off.
Center and mount these strips to the backside of your ledger...correspondening to the hole layouts. You can either screw these strips in place or better yet, tack them in place with a 15 guage finish nailer. Keep top of strip 1/2 inch lower than top of ledger.
Once strips are tacked, use holes on front side of ledger as a guide and drill completely thru the 2x spacer strips. Now you are ready to re-install ledger and bolt into house rim joist.
Before bolting into place, use a good quality caulk/sealant, and dab some around and in each drilled hole location that penetrates the house. When installing the bolts, dab some more caulk over each bolt head after torqueing.
This technique is similar to using metal washers for spacers behind the ledger, but The wood spacers do a better job IMHO.
Davo
I've done more or less the same thing but used Azek strips ... very happy with the result.
Strips of plastic decking like Trex also work well for this.
What really gets me is how many decks you come across that have absolutely no flashing between the deck and the house. I see this all the time. Ledger boards are just bolted into the house clapboards. I suspect you probably see this quite often as well, huh?
And of course, I prefer to bolt my ledger clear thru the rim joist using carriage bolts or long threaded machine bolts...but I still see a lot of guys using 3-1/2 or 4 inch lag bolts. I just shake my head.
Davo
Davo, I see a lot of that too. I have a neighbor down near my camp, which is up about 8', and the bolts are only about 5/16', and through 1' foam. I have brought it to their attention. I hope they never have a big party down there. The dad weighs about 300# and the son is ~ 275#. Thanks to all who have offered ideas. K
Davo, that's a good technique to a point, and it does a great job promoting drainage. A lot of inspectors will pass it, but if you dig really deep in the 2007 supplement to the IRC, you might find it's a violation. Here's why. When the ledger is tight to the house (with a flashing layer in between) the bolts are loaded in shear. It's a simple and strong connection. When you introduce a space, it's not longer a shear connection and you're relying on what's called the moment strength of the bolt to support the load. I'm not an engineer, but I'm told that's a more complex calculation, and the bolting tables in the 2007 supplement to the IRC don't apply to it. The largest space you're allowed by that version of the code without engineering is 1/2 in.Andy
"Never try to teach a pig to sing. It wastes your time and annoys the pig." Robert A. Heinlein (or maybe Mark Twain)
"Get off your dead #### and on your dying feet." Mom
"Everything not forbidden is compulsory." T.H. White, The Once and Future King
One option is to put some footings in next to the existing foundation and leave the deck freestanding, with ~1" between the deck band board (it's no longer a ledger in this case) and the siding.
No intrusions into the existing wall, no one falls into the gap, and no place for the goop to build up. Everything lasts longer.
This assumes, of course, that your deck isn't too high above grade.
-t