I just added a deck across the front of my house. I would like to extend my basement shop and make the space underneath the deck useable but need to make it water-tight from above. I thought about using a piece of metal duct work to fit in between the joist runs as a trough to channel water off. Will this work or is there a better way? I haven’t installed the decking yet so I still have access to the top of the joist runs.
Keeping Dry…
Replies
I'm looking at the same problem and have found several solutions:
1. Interlocking metal decking like that available from http://www.lockdry.com. It's a good solution, durable and long-lasting, but expensive.
2. Similar to your proposed solution, check out http://www.dryspace.cc/. Would work, but you need some kind of drainage system and I wouldn't trust it for having actual living space under it (as opposed to just a covered porch area).
3. Roof deck coatings. You'd replace your decking with plywood, and then use one of the new hi-tech coatings like: http://www.grailcoat.com . This is what I plan to do with my deck, though I'm not putting living space below.
4. Rebuild your deck so it is a proper roof-deck. This is the best solution, but obviously the most expensive.
Hope that helps,
Andy
Check out this site http://WWW.Duradek.com
Duradek looks like a good product, but you can't install it yourself.
All,
Thanks for the information on the under-decking options. I found another one that uses a membrane instead of metal. It runs about $3.50 per sq ft but looks promising.
I'd like to insulate the area under the decking and the metal options apppear to take up a ton of room.
Here's their website: http://deckdrain.com/products.asp
Zac
Sure you can.
They even have a glue and roller system instructions and everything.Quality repairs for your home.
Aaron the HandymanVancouver, Canada
You maybe right, I was just going by what is on their website, which says you need to use a "fully trained applicator."
Andy
Andy you are correct it does have to be done by a trained applicator. There are similar products on the market but without the same warranty.
A friend of mine wanted a dry space under his mohagany deck, so they fashioned an drainage system of fiberglass panels, you know, the wavy stuff (forget the name, showing my age.) Anyway, he called me six weeks back, seems his deck buckeled in two places, ripping the Eb-ty system right out of the joists. It was finally determined (by the contractor who installed it, whom they haven't heard from since) that the rain catcher didn't allow suffient drainage, withholding moisture, which caused the wood to expand and expand and expand, until I got a phone call to come over and fix the deck.
The good news is I get to rip up the deck and install it without the Eb-ty system. When I can squeeze it in. (Pun intended.)
The point is, ensure your system adequately drains off the moisture, or you may be looking for someone to fix the deck later on.
It's already a little late because the right way to do this is to build the shop out, roof it and then build a deck over it. Anything less will be a compromise in waterproofing.
Excellence is its own reward!
Piff--
He still has his joists uncovered; he should be able to do it from there.
I just finished a deck two weeks ago with the same requirement: dry space underneath. What I did was to set the joists with a low pitch, about 1" per 10' (he'll have to nail long wedges onto the top of his joists unless he wants to cut the support posts and just lower the whole outboard end of the deck to give it the slope). Then plywood on the joists like a roof deck. Drip edges bedded in pitch go on the outboard exposed end grain of the plywood. Ice & snow membrane over that, flashed up into the siding where it meets the house.
We cut 2x rough cedar sleepers to the complementary slope so their tops would be level. The rim sleeper had weep holes bored in it for each sleeper bay. I lag-bolted this rim sleeper down over the drip edges; the rest of the sleepers were nailed through or toe-nailed where they were too thick to penetrate. The deck (5/4 cedar R.E.D.) was screwed on with stainless steel screws.
To hide the drip edges and the weep holes and the sleepers, I ran the decking about an inch and a half past the face of the rim, tacked some support blocks onto the face of the rim sleeper and rim joist, and put a 1x6 pine skirt board on tucked up under the overhang. This lets water weep out and run off past the rim joist. If his shop wall is going to be flush with the face of that, he'll need to install some kind of gutter system or he's gonna get water staining big time in no time. I'd actually suggest he set the shop wall back a few inches at least.
Dinosaur
'Y-a-tu de la justice dans ce maudit monde?
ya, done similar but it'ss till a compromise and not a real roof.
One that I did similarly was over open underporch space. I was just trying to make it dry enough for storing garden tools. No sooner got that done than the owners wanted to make it finished living space! I declined unless they let me redo whole thing to be gauranteed waterproof.
next time I went to visit, they showed me the "wonderful TV room" they had created with a hack carpenter who didn't care how long it lasted.
Then they had the nerve to ask if I could fix a little olde leak...
eegads! Had to remind them that I had predicted this and ask if they were ready to spend the real money for the real roof job. nope. Instead of spending two grand on roofing, they will waste the ten grand they have in work under it..
Excellence is its own reward!
Piff duradek is a real roof. Check it out. I bet there is a project some where in your area.
Dinosaur -
Would it be possible to post a pic. I am also very interested in your proposed solution.
Thanks Dean
I don't have any photos of that site; I'll be over there sometime this week but the HO's gone missing for a few days--or he might just be on the golf course.
I can make a sketch of the assembly and scan it in a little later today. Stand by...now where did I put that ACAD disc???
Nah-- if I try to use the ACAD, by the time I figure out how to run the program, you'll have grandkids playing in the TV room under that deck. I still got my pencils and MS paint, though. Later
Dinosaur
'Y-a-tu de la justice dans ce maudit monde?