Flat roof houses - PeachParts Mercedes-Benz Forum

Kuan · #1 12-28-2006, 06:36 PM

My flat roof is bloody leaking despite a few attempts at patching. Any flat roof doctors, self proclaimed or otherwise, willing to dispense advice?

Brian Carlton · #2 12-28-2006, 07:00 PM

...........flat roofs.........

The worst decision I made on this house was to put a flat roof over the porch instead of the traditional gable roof. Thought it would have a cleaner look.

Anyway, when you own a flat roof, you chase leaks. The problem, as you know, is that you can never quite find them. In my case, the porch ceiling is open and I can view the source. The best way to patch them is to use some membrane and spread the roof cement over that. The cement itself doesn't really enjoy filling holes very well, but, when used in combination with the membrane, you can usually get some measure of success with it.

The alternative is to put another roof on top.........glue down or torch down..........then you finally fix the problem for another 10 years.

Matt L · #3 12-28-2006, 07:03 PM

Torch-down, for sure. We got one recently, with a ten-year warranty as long as it has an application of some sort of silver goo after five.

Dubyagee · #4 12-28-2006, 07:08 PM

http://www.hydro-stop.com/Frameset-1.html

kerry · #5 12-28-2006, 08:06 PM

I installed a torch-down on the flat portion of my roof in 1990. Materials had a 10yr warrantly. It is still holding up fine with no evidence of any problems. I did have to torch down about a 6 inch portion of one seam with a small plumbing propane torch about 5 yrs ago. Very easy to install. I watched an instruction video at the place I bought the materials. I highly recommend it.
Have done a couple more roofs with it since then.

#6 12-28-2006, 08:21 PM

I have heard that Conklin makes a good rubber rof system.

t walgamuth · #7 12-28-2006, 10:02 PM

i generally try to avoid flat roofs at all costs.

one trouble with them is that where the water appears below can be a long ways from the source of the actual leak.

figuring out ways to design a building and avoiding flat roofs is a special skill of mine.

i have done successful conversions of a number of buildings from flat to pitched roofs. i have a fairly large church project right now that is almost ready to go out for bids.

tom w

kerry · #8 12-28-2006, 10:08 PM

Quote:

Originally Posted by t walgamuth

i generally try to avoid flat roofs at all costs.

one trouble with them is that where the water appears below can be a long ways from the source of the actual leak.

figuring out ways to design a building and avoiding flat roofs is a special skill of mine.

i have done successful conversions of a number of buildings from flat to pitched roofs. i have a fairly large church project right now that is almost ready to go out for bids.

tom w

Done it to any FLW buildings?

t walgamuth · #9 12-28-2006, 10:11 PM

not yet.

we do have one very elegant house here by him. i have been through it a couple of times. it is owned by its very nice and interesting gentleman who is in his ninties. he is establishing a trust to preserve the house for posterity.

i am not holding my breath on fixing any of frank's work.

we also have a very elegant little louis sullivan bank in west lafayette which i would love to buy, which has been "modernized" inside with an atrocious dropped ceiling. i would hope that above it there is some interesting cove moldings and perhaps some skylights.

tom w

MS Fowler · #10 12-29-2006, 08:39 AM

One of the uses for the moisture-density gauge that we use to check the compaction of soil that is being placed as backfill, is that they can track moisture in a flat roof.
One can lay out a grid on the roof,make moisture reading and then plot up the results in sort of a topo map of moistures. Often this method revels where the hidden moisture goes below the membrane so that it can be fixed.

I've done this procedure on a few roofs, but it is a time-consuming ( and therefore expensive) process. Sometimes its just easier to re-roof.

Kuan · #11 12-29-2006, 08:58 AM

I can't fix it in the winter can I? I've been sweeping the roof everyday.

Do those wall moisture trackers work? The ones at Home Depot?

t walgamuth · #12 12-29-2006, 09:21 AM

there is tar that is designed to be applied to wet surfaces for a temporary fix. course you will need to know where to apply it.

if you dont know where your leak is the most likely places are around any penetrations like chimneys or plumbing vents. changes in level such as where the roof line jumps up to a higher level, and edges.

the open flat areas seldom leak. in my experience.

tom w

Matt SD300 · #13 12-29-2006, 11:48 AM

Quote:

Originally Posted by Kuan

I can't fix it in the winter can I? I've been sweeping the roof everyday.

Do those wall moisture trackers work? The ones at Home Depot?

if you find the leak... it can be patched with HENRYS WET PATCH (blue can)

POS · #14 12-29-2006, 08:04 PM

I have a flat-roofed house and I've lived here for 6 1/2 years without a leak. However, in Jan/Feb we will be putting on a gabled roof prior to a leak beginning. Biggest issue I have with a flat-roof is you have zero attic space.

Zeus · #15 12-29-2006, 08:45 PM

My $0.02 - Ah...flat roofs on residential homes. I see them up here in Canada and I shake my head. I ran a roofing/contracting business for close to a decade and have done my share of roofs. Not too many flat ones, I tried to stay away from those headaches. They really don't make sense unless one lives in Tuscany, IMO.

We can blame Frank Lloyd Wright, I suppose.

Unless the leak is readily apparent, they can be very difficult to diagnose. Leaks tend to snake their way down studs, across joists, get soaked up in ceiling drywall and insulation, come out of fixtures, etc. In an open attic, it is usually much easier to identify a single leak as you can see the actual entry point.

With a flat roof, if you have a leak, you could actually have several entry points - or a large area or seam failing. Compound that with how and when the leak(s) occur. Only when wind drives rain? Or a slow leak that shows up after rain has passed? Or is it when snow accumulates, you get ice build up and then it leaks, etc.

How old is the roof? Is it a mansard style? Mansards are notorious for leaking at the edge of the flat roof, where it meets the steep mansard portion - that flashing joint will always fail, especially if re-shingling has been done. The pressure of workers stepping on the flat roof, ladders against flashing, and weight of shingles and materials can easily break that joint.

If the roof is aged, I would save yourself future hassle and strip it down bare and re-roof. Strip to the decking, inspect the decking for rot and sags, correct slope where necessary and re-apply the proper product for your area. Hire a local pro with ample references.

If you patch, you'll probably end up climbing up there each season, tar brush in hand...

Good luck Kuan!