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waterproofing leaking garage roof/deck

Posted by shawndang (My Page) on
Sat, Feb 24, 07 at 18:35

I have a garage that has a flat roof, which is our deck and it's leaking pretty bad. We had porcelain tiles on it. The deck was supposedly waterproofed using some thick black material and was melted using a blow torch. Then it was mudded to give it a slope and then tiled. Alas after one year the deck is leaking badly and the water is getting into the gararge.

We are going to get the tiles and the mud ripped and get it re done. We do have two square posts on the deck as well.

What is the best way get this to be waterproofed. I Just don't want to get it redone again and again. All advice is appriciated.

Thanks in advance


Follow-Up Postings:

RE: waterproofing leaking garage roof/deck

The longest term flat roof surface remains EPDM membrane.

RE: waterproofing leaking garage roof/deck

Where could we purchase that from? Would lowes or Home Depot have it.

RE: waterproofing leaking garage roof/deck

From what your saying I am thinking you have a torch down modified roof, a grade system added on top of it with masion material then tile installed on top of the mortor. All this was done around two posts coming up thru the roof and the tile.

This project is leaking after only one year.

The Roof is not at fault,several things most likely happened after the roof was installed>>> Workers walked around on it loading material,masons droped tools on it,nails were pushed thru it, the flashing around the posts was not done corectley,things like that. With that kind of an install many workers could have done damage to the roof, Left undamaged a modified torch down done corectley and not punctured after completion is a 40 year+ roof. John

RE: waterproofing leaking garage roof/deck

John thats exactly my setup. This will be our 2nd go around at the same problem. I read on a diff site that you have to have a layer of 1 inch high stones between the membrane and tiles so that the water can run off. Is this necessary?

What do you think about If I get the tiles and the mud ripped and get the membrane redone. But this time have the water slope toward the center of the garage and have a drain there (sort of like in a shower) and then have the drain pipe go out through the side of the garage away from the house.

This will eliminate my need to have drains around the edges of the garage which I currently dont have and no flashing either. Or is it better to have water run of the edge of the garage and get a gutters put in?

RE: waterproofing leaking garage roof/deck

brickeyee, my deck does not have any natural slope to it. Tile guys had mudded to give it a slope. Is it better to mud above or below the EPDM. Currently it's got membrane then slopped mud, thinset and tile.

RE: waterproofing leaking garage roof/deck

A tile deck has been brought up over here before, I my own self have been trying to figure out how it would work and stay working down the road. In the past we All were thinking plywood/cement board/ tile one guy tried it and posted pictures of the failure,none of my little test decks doing it that way worked real well either.

Building it like a shower and using the modified as a shower pan I have thought about but never tried. I have several projects out with modified/stringers/ decking 9 years or so out with no problems. And I know a torchdown will last done corectley on a comerical roof granulated or smooth surface for many years so all I can give you are ideas

Dont make the fall center on a main drain that would be installing a leak, dont buy any thing serious at the box stores, if your going to do a tear out anyway frame the fall with cant strips fastened to your rafters and re deck,if you can dont have the posts going thru the roof if they have to be sure all needed flashing is instaled corectley and the posts have solid bearing.

I still am coming back to the workers far as the leaks go, the worst thing for a roof is people walking on it x 100 the basic concret guy placing the creet base (dont use stones)the chances of a sharp heal,droped trowel,talking on the cell and droping a pencel then steping on it things like that are just to great to expect something not to happen to even a perfect roof/flashing install.

I would come closer to trusting 3'' of light weight creet placed over plywood with flashing all around then using very close tolerance com tile,thin com grout line,instaled with construstion adhesive with several coats of high grade uv sealer. J

RE: waterproofing leaking garage roof/deck

I have a garage that has been leaking for three years. My garage is attached to the garage next door and the water comes in from that side. My garage roof slopes to my house on one side and the flashing is paper. The roofer said that the water is coming up from the foundation. I had a contractor look at it and he said water goes down not up. If it rains light I have not problem, but it it rains hard my garage floor is very wet on one side and the other side is now starting to leak. I put plastic out on the space between the flashing and the roof and the water seems to not come in as bad. I still think it is a cricket in the roof.

RE: waterproofing leaking garage roof/deck

My mate had a garage with a similar problem. I think he used this stuff called RapidRoof. I'll put a link to the website for anybody interested.

Here is a link that might be useful: RapidRoof

RE: waterproofing leaking garage roof/deck

We have a deck that can't be a garage due to county restrictions, so it's an open air thing, but a huge deck. It is over a lower driveway. Former owner parked his boat in it. It's over the septic field, so has removable brick flooring.

It had been neglected for years prior to our purchase and we just had the whole thing redone. You couldn't walk on it there was so much rot and termite damage.

They took it down to the framework, replaced some of that. Then they put plywood over all. Then tar paper laid in different directions to prevent leaks in seams. Then they did some kind of skip trowel finish that comes in many colors. It's been a year, and it does not leak. But they did not have to mud it for drainage because it was sloped correctly in the first place.

We do have other decks they had to mud. None of those leak.

This post was edited by desertdance on Tue, Jul 29, 14 at 9:49

RE: waterproofing leaking garage roof/deck

My opinion?

Demo it to the deck floor joist framing, for clarity the deck floor joists are the same as the garage ceiling joists/rafters.

If your roof framing is essentially "flat" or minimally pitched, or pitched poorly, then I'd sister new deck joists to the existing, but sister them so they are pitched for drainage across the entire plane of the roof deck.

On top of those new pitched joists, add plywood sheathing, you may need ply underlayment as well.

Here's where things diverge.

I use NobelDeck membrane on tiled deck surfaces with living space below. The overall instructions can vary with regards to the space below being conditioned, or if you are in a freeze/thaw environment. So refer to the Nobel website for specific installation instructions, or call their friendly tech department for added info. some cases you can put the NobelDeck right over the plywood, then tile on the membrane. In others you might have to add 1/2" cement board over the ply, then install the NobelDeck over the cement board. Climate matters too, if it's a freeze/thaw climate, etc.

The last tiled balcony I did was done with cement board as the space underneath the tiled balcony was part living space (front entry vestibule) and partly open to the environment (front porch), and it's in a freeze/thaw climate.

NobelDeck is an excellent membrane.

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