flat roof leak, eek!

hi,
new homeowner here... I own a 3 unit building in Brooklyn.
It rained on Monday, then on Tuesday the 3rd floor tenant had water dripping out of a ceiling fixture. Not gallons and gallons, but a few cups at least, if not a quart.
Anyway, I went up on the roof and, being new to this, I didn't find a specific crack or broken seam or obvious flashing problem. Today I'm going to try to crawl into the crawl space and see if I can find where the leak is coming from.
The roof is rubber I believe. Strips of material all covered with a thick gray/silver paint. It is noticeably soft in some areas, particularly in the area over where the leak took place. I'm not sure if its emergency-crisis soft, or just a bit soft.
Basically my questions are:
what do I use to patch this kind of roof?
any hints on how to figure out where to patch it? If I can't find a specific leak point my guess would be either up the slope from the soft points and probably in the gutter area, where it is softest.
Do rubber roofs leak through eventually? There are some areas where water clearly puddles, but there's no crack or split. There may be some hairline cracks. Basically I don't know what to look for, short of a large gap or obvious loose seam - which I don't see.
Any advice appreciated, I've looked online but found little in the way of flat rubber roofs other than RV homes.
-Ben
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First, are you sure it's rubber? Could it be roll roofing instead?
One repairs rubber roofs with pieces of rubber roofing material, available at roofing suppliers; plus the special adhesive. Very much like fixing a bike flat tire.
But as for finding the source of the leak, that's often mysterious and frustrating. If the original rubber has been coated with a paint, that may be a sign of its age and perhaps previous leaks. There is eventual aging, you know, that requires re-roofing; or at least, hiring a roofing co. to repair larger sections of it.
Keep on searching online for more info - I know it's out there. ?ut first, make sure it is actually rubber. If you can, find out bldg. repair history from previous owners.
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Did you get a roof inspection before you purchased the property? I'm managing two buildings for the past 25 years with flat roofs and it has been problematic to say the least. I'm a DIYer and could repair a few things including tile and composition roofs but a flat roof is not one of them. I would look at the age of the roof first (age and condition disclosure from the seller?). If its over 15 years old than a new roof maybe the cheapest way to go. If its under 7 years then perhaps a repair job is the most cost effective. Your roof could be modified bitchemen (long strips lay down with a torch) and the silver layer could be sun and UV blocker. I would get estimates from a few good roofers first to found out the type of roof and cost to repair. You then decide on repair, replace or DIY. Good luck on the new rental - keep the tenants happy and the cash flow positive!
BTW, Google return with 613,000 hits on flat roof repair: http://www.google.com/search?hl=en&lr=&q=flat+roof+repair&btnG=Search
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Unlikely.
Roll roofing covered with an aluminized paint used to extend the life of the roof by 3-5 years.

Soft is not generally a problem. In fact the idea is to have the asphalt binder a little soft so it spreads out and prevents leaks. It's when it's hard and brittle that the problem occurs. Of course the softness could be a bulge of water between the layers of roofing. This you would have to get rid of.

See below.

Very hard to find leaks. Most people don't bother.

Not cheapest but certainly worth considering.

Not in Brooklyn these days. Torch-downs are illegal -- thousands of $ fines if you're caught -- but that doesn't stop the occasional Russian roof guy doing it on a Sunday.

Advice:
I also have a brownstone in Brooklyn. Go down to Home Depot (or Lowes) and spend an hour in the roofing aisle reading the cans. You'll see what to use to repair the cracks and bulges and IIRC they even have some brochures with a step-by-step process.
Absent any obvious crack or separation (look at the edges) the cheapest solution is to buy some more of the aluminized coating (around $60 for 5 galls IIRC) and paint the roof. It'll last you 3-5 years. Then you can do it again.
In contrast a new roof (just over the top, no tear off) will cost around $3,000. The last time I replaced my roof I priced an EDPM (rubber) substitute but the cost was out of this world. Around $10,000 IIRC but it's what the commercial buildings use and is supposed to last much longer than the asphalted roll roofing which is only good for about 15 years.
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Well I should note, its not FLAT.. but sloped. If you put a ball on it, it would roll from one end to another.
I tried looking in the crawl space but it was too damn short at the end where the leak possibly is. I could only really look at the first 20-30 feet of the building (the leak is about 50 feet into the 60 foot building). It all looked dry in that portion of the roof, which means nothing of course.
I had a roof guy come over to do an estimate, but he wasn't the guy who'd actually be doing the work. He said it would be 700 bucks to fix the leak, but he couldn't tell me how they would fix it - not even like the process they would go through to find it. He just told me they'd "fix it. 3 year guarantee." I didn't really feel confidence in such a vague estimate.
He did seem to think the roof was in mostly good to very good condition. He noted that the building next to me had obviously put one or two new layers on top of old layers, while whoever last did my roof had actually stripped off the old and put down a new one, which is good.
He claimed there was no flashing on the 3 or so protrusions (vents, skylights, etc), but I was unclear how he could tell, as it was all covered with the strips of roll roofing, tar/asphalt/whatever, and silver paint.
Wouldn't the flashing, if it existed, be under the roofing material? Anyway, I think he's right, but most of the areas that would need flashing were covered with contiguous pieces of roofing material and I can't really see where the water would get in.
Anyway, when I was in the crawl space I found the former owner's can of "Asphalt-Asbestos Roof Sealant". Basically an air-dry tar like substance.
I slathered the asphalt on all the protruding edges, vents, and a corner of masonry that looked a bit cracked (okay a little more than a bit). It rains tomorrow, I'm hoping it won't leak again!
If I have time I'll see about running down to lowes or somesuch and picking up some more roofing repair materials.
About flashing... If I wanted to flash the protruding elements, I would have to take up the roofing around them first, right?
-Ben
snipped-for-privacy@NotRealISP.edu wrote:

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the cheap fix probably amounts to a mop coat of the entire roof area in question. that way, they don't need to figure out exactly where the leak was. if some structural movement was responsible for the initial leak, it will probably reoccur after similar temperature cycles.
sometimes you can get an idea of where a leak might be by inspecting the suspect area fairly soon after a rain. any pores, cracks etc, with water in them will be the last to show visible moisture. this method can at least eliminate some areas from consideration.
bill
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Yeah, sure. Every "flat" roof is slightly sloped otherwise the water would just pool in spots.

Everyone has the same problem. Your next will be when the now rotten plaster around the light fitting etc collapses. At least that will allow you to have a look in the appropriate area of the crawl space. Watch out for mold and wet insulation.

If he spoke English he's not the one doing the work.

Sounds like he's just going to paint the entire roof with the aluminized paint. Price would be about right. Of course you can do it for about $120 plus your (free!) labor.

Unlikely. These type of roofs don't usually leak for the first ten years. After that they start leaking.

Most of the time flashing is done with the roll material and the asphalt. The only places I have aluminum flashing is on the back extension where I put it in myself.

Yikes! Asbestos! How many years old is this?

You're too optimistic. You need to cover the entire roof to be certain but use the aluminized fibre reinforced paint. The "roof sealant" is probably the stuff used to stick down the roll roofing. On its own it won't last out the year.

If you want to do it like a suburban house, yes. However this is not the same thing as a shingle roof. Because of the easy accessibility and the fact that it's already a continuous layer of asphalt/rolls you can just extend the asphalt up the protrusions with little cost. Independent flashing isn't going to do much for you given that unless you buy an EDPM surface you're likely to be working on this every ten years or less.

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If you want to get into roofing, try the NRCA web site. The technical section is extensive. If you browse the construction details, you would get an idea of how flashings look. That might help when looking at the roof penetration flashing. TB
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On Thu, 31 Mar 2005 14:36:56 GMT, Ben Gold

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Well the ceiling is tin, so no plaster to come down... however it makes figuring out where the leak is much more difficult, as water leaking anywhere within a 15 foot radius or so will always find its way to the fixture.
Its raining today so I went up on the roof to check it out. Water was rolling down the roof pretty well, a few puddles on the low side, can't tell if it's soaking through - but I'd guess not. Water flows into the drain pipe well, but I suppose there could be a crack there that lets water in.
However, I looked down two vents on the roof and one of them at least had water in it about 8 feet below me!!!
I assume its clogged with debris and has been filling up regularly. Egad.
I'm not sure what the vent is for, but I think it's a vestigal stove pipe. There are 3 units, and 3 vents - one of which is sealed up. It's actually between my building and the next one, so I'm not positive it's part of my building - but it seems likely that this could be the leak, as it is right beside the kitchen where the leaking fixture is.
I put an inverted bucket over both vents and will check it out when its dry. Fingers crossed.
-Ben

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I doubt it's tin. Most likely steel although often called a tin ceiling. Does it have a pattern and is it in 2' * 8' sheets (or 2' * 4')? If so you might be in luck. Every six inches or so there's a dimple in the center of which is a nail (it's probably crud-ed up with paint). Very carefully remove the nails down one side and you'll find the sheet can swing down so you can look into the space above. Also check out if the back side is rusted.

Do you mean a vent as in a plumbing vent? A pipe about 3 or 4 inches in diameter usually cast iron? If so you would have a slow running drain if it's clogged. If this is thin steel like a gas water heater vent make very sure it's not active on occasion. If you cap it you'll cause all the flue gases to back up into the house.
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I think it IS tin... or at least an old-school metal ceiling. The building was built in 1896 and there are metal ceilings in 3 rooms on each floor, varying from 10 x 5 to something like 20 x 9... I'm not messin' with them unless I have to.
....
The "vent" I found was a chimney flue, round masonry top with square brick inside. I'm pretty sure it's unused... but I have to check with the neighbor to make sure its not his. They're next to his radiator flue.
There are two other cast iron vents that I think are the plumbing vents.
So, when it stops raining, I'll got up with a flashlight and see what I can see. Thanks for all the help.

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Flat roofs will always leak...get used to it
On Thu, 31 Mar 2005 14:36:56 GMT, Ben Gold

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