Waterproofing a screen porch roof deck
ms4343
| Posted in Construction Techniques on
Has anyone ever come accross a detail like this?
I have a existing balcony on the second floor over an existing deck at the first. I’d like to create a three season room at the first floor level. Because of cost, I’d like to not have to remove any of the decking and detail at the second floor balcony. Is there any way to do so? I was thinking that if there was a way to run a tappered material between each joist and have it run all the water to the edges and then create a new ceiling under the joist, it might keep me dry.
Can anyone help me?
Replies
There's a rubber product that looks like rubber roofing, I can't think of the name, that is sold for that application.
I'll be doing something similar this spring though with sheet metal. I'll have shallow u-shaped pans made up and will screw them to the joists with a slight pitch. It might not be 100% waterproof but it should be close.
would you be thinking of EPDM????
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!Forget the primal scream, just ROAR!!!
I thought of EPDM but if I was going to remove the existing balcony, taper my joists and use a sleeper system w/ new decking. I'm trying to attack this thing from the underside, trying to leave all that exists in place.
Thanks, but I'm thinking of a trade name. It looks like EPDM cut to specific sizes, but I'm not sure. It was discussed here a year or two ago.
I've actually seen it done on one of those home shows several months ago but I think it was in a warmer climate zone. One of my oter concerns is, if I am able to creat this troth if you will, will I run into the problem of ice damming and will it blow my joists apart in the winter months? Are you in one of these climates, have you thought of that? What are your thoughts?
I think that's more what I was thinking of. Something that can go between the joists that I could pitch and leave the bottom of the joist available for strapping and bead board ceiling. Where are you located, will you have any troubles with ice/ ice damming?
I'm in Maine, Ice Dam Central. The deck is on the south side though with good exposure so I'm not too worried. I'll put some support pieces under the metal anyway.
Where are you?
http://www.gacoretail.com/gacodeck.html
There are other manufacturers of similar products.
I guess I should say rubber membraine. I think it needs to be installed individually between each joist, not sure how I'd use a sheet produce going in from the underside.
I must be missing something here. Why are you trying to build a roof under a roof? Seems easier to make the existing upper deck/roof surface waterproof, then all the work is done under it as if standard construction.
They can't get your Goat if you don't tell them where it is hidden.
thinking about it....
that'd be along the lines of waterproofing the inside walls of a leaking foundation...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!Forget the primal scream, just ROAR!!!
I have done what he is talking about but only for carports where a second story deck was built with cedar decking that was spaced 1/4" or so . I wouldn't try it to create a "seasonal room". Easier to lay some ply down and water proof it with a walkable membrane.
They can't get your Goat if you don't tell them where it is hidden.
Your not missing anything, the joists, decking, railing system is all in place. In order to do it the "standard" way, would require the removal of the entire system. I'd have to remove the railings, decking and even the joists to give them a taper. Then, I'd have the re-install the joists, apply sheathing, railing system, membrane w/ boots around the posts, sleepers then decking. If I could go from the underside and between the joists with a tapered system of some sort, all of the above wouldn't have to be touched. What makes more sense to you?
Edited 4/18/2008 1:18 pm ET by ms4343
What is the current deck made out of and how is it finished? I am making some assumptions based on a mental picture of what you have. If it is a standard old fashioned hot mop or solid deck surface I wouldn't be tearing anything off at all.
I would buy some tapered insulation (available through commercial roofing outlets) and cover that with ply then the waterproof membrane. If it spaced decking I would do the same. You don't need much slope if the area isn't too large. In fact if the roof is flat it would probably be fine, it just needs not to slope back to the building. No need to remove rails/posts, there are standard details that will handle those in all of the install directions for the types of products I mentioned. Got a picture you can post?
They can't get your Goat if you don't tell them where it is hidden.
It is a spaced decking constructed out of pt. The problem with adding on top of the deck is that there isn't much room between threshold and top of decking, only several inches. I also want to walk on this deck which would require a tapered with at the least a 1/2" fiberboard. The deck is 12' from threshold to rail. Cost is also an issue.
Ooops, the photo's up-side-down, sorry
Edited 4/18/2008 1:41 pm ET by ms4343
Here, this might be a little better.
http://www.undercoversystems.com
And there are other similar manufactures and devices. I'm working on putting this on my deck so the ceement patio under has rain protection.
That looks like what he is searching for. Interesting solution. How do you keep the hidden gutter clean ?
They can't get your Goat if you don't tell them where it is hidden.
Assuming the narrow spacing commonly used on decks, most junk will be filtered out by that.
Thank you very much for the link. However, I just toalked with the company and for the cost of the product to order and then shipping, it would be faster and cheaper for me to just re-build the deck above.
Thank you again for the link.
Google "under deck drainage systems" and you'll get a lot more companies, perhaps some closer to you and better priced.
However, I did something similar as a DIY approach some years ago.
Look again at your picture. See the carrying beam on the away side (from the house) sitting it's depth below the deck joists?
What I did, was to rip some 5/4" treated deck boards (a touch longer than the length that the deck is wide) to form two long tri-angled ones from each board. Each of these resultant boards were then attached (in the same plane) to the bottom of the joists (near the house) and then hangered to the aforementioned carrying beam (on the inside). Thus creating a "rafter."
Then I picked up some heavy duty corrugated fiberglas roofing panels from the lumberyard (HD's is a bit too flimsy). I choose the almost clear transparent ones so I could identify accumulation problems. Also got myself a bunch of small rubber washers - about the size that would fit over a piffin screw. And some galvanized piffin screws.
The wall under my deck was bricked. Therefore, just below the deck joist, I cut a shallow groove into the brick with a diamond bladed angle grinder the entire length of the deck and set in a long piece of flashing, slightly bent to match the angle of the ripped "rafters." And sillyconed it into the brick groove.
I cut the fiberglas panels to run from the house to just outside the carrying beam (so the panel formed little drainage ditches out to the low side). Then attached each panel from underneath using the rubber washers and galv piffin screws, overlapping each panel by about 3 inches. Whatever water dripped thru the deck would then drain beyond the carrying beam.
Presto! A perfectly dry nether-patio. Great for keeping the radial arm saw outside and dry or whatever else.
Far cheeper than the guys in the link I provided. Last I heard 10 years later, it was still holding up just like new.
Thank you, that's just what I was thinking of how it might happen but wasn't too sure ofhow water tight it might be.
Thank you
http://www.underdeck.com has a system that looks easy to install. I don't know how expensive
I Googled the under deck drainage systems and went to DIY home center. They had a product and cost estimater. It seems very effective, quick and simple to install. This looks like exactly what I've been looking for.