Deck Over A Flat Roof

Same Old

Does anyone have a good method for this? I've done it before but I never really liked the finish.

I'm hoping there is some deck system out there that is made for this.
The application I am looking at is for some type of wood deck with railing above 19x 20 garage.

tcleve4911

Questions -
Can deck material touch the roof?
Is the flat roof rubber?
How much thickness is available to door accessing deck?

__________________
Back in Maine
Dubbin' Around
Doin' good stuff ......

thom

I do it a lot.

Use a torchdown roof. built up with gravel will be a problem. Built up without gravel might be all right. Roof drainage needs to slope properly.

Install 2 X 4 Sleepers on pads, directly over joists or perpendicular to existing joists. They cannot go parallal but not directly over. The pads are concrete expansion joints. I'm sure you've seen the stuff, 3-1/2" wide by 8' long asphalt impregnated fiberboard.

Screw the deck to the sleepers.

You must make sure you have adequate drainage between the sleepers. Screw this up and you've got a problem

You must make sure the roof joists are sized for a floor load. Standard roof joists have an inadequate load capacity.

The problem with a built-up roof with gravel is that you will be pushing the gravel through the roofing over time, creating a leak.

The point of the pads under the sleepers is to even out the load on the roofing so you don'nt develop places where the sleepers cut through the roof over time.

AtlanticWBConst

Check this out:

http://www.bisondecksupports.com/

Looks like a great product. Discovered them at the Last JLC show. Only $12.00 a piece for the regular supports and $14.00 for the Heavy Duty.

__________________
- Build Well -

Same Old

I've done the sleeper method over epdm, but I never really liked how it forces you to a single slope and the awkward drip edge.

Those Bison supports look like a good bet over a preformed foam underlay.

Thanks for the input.

Same Old

Right now there is nothing built and the arch's plans are extremely lacking in details.

RLGC

Have you concidered a fiber glass deck. The problem with rolled roof is its only guarenteed for ten years. ??. Wherever you nail or screw through is vulnerable to leaks. If you value what lies below your roof and don't want the inevitble headaches long term, fiber glass might be a good solution. I have used it twice for your situation. No complaints

keepitstraight

wife and i are looking at building ourselves a santa fe and i think that we've pretty much decided to go with an epdm membrane on the deck and covering the membrane with foam. apparently the main reason for failure on membranes is that even with uv resistance, they expand and contract in direct contact with sun and weather. then they shrink and ull loose. the foam prevents extremes on the membrane's expansion/contraction and gives you a safe place to lay duckboards, decking, etc.

i am definitely going to have to look at this attachment further though. thanks, atlwbconst. love this about these forums; see perspectives through a larger field of experience and widen the rut of habit.

thanks all.

Same Old

I'm not familiar with fiberglass decks. This is for a fairly nice neighborhood, I think I'll go with the Bison system over epdm with Ipe panels.

M&R Roofing

When installed properly as a floating deck, a deck can sit on the roofing membrane. We are primarily installing two ply modified bitumen flat roofing systems. When we do install wood decks over the flat roofs, we ensure they are floating, so that there is no punture or penetration of the rubber membrane. The flat roof should be sloped appropriately as always and the decking should be laid parallel with the slope run, so that drainage is possible. Also note, that the deck must be stabilized by being attached to the building. There are several different options to attach the deck to the structure. We have installed several such decks. I recommend you take a look at our work. You can get a rough idea by watching the video below.

I am still new to the site and must have 15 posts before being allowed to post urls. Go to mandrroofing.ca and click on flat roofs in the blog categories.

Gary Garrison

Use Hydro-Stop waterproofing membrane.