Flat roof repair

I have a conventional built-up flat roof on a concrete deck with dozens of blisters, nearly every single seam in bad condition, and water infiltration at at least one (probably more) penetrations including the bathroom exhaust fan duct shown in the last two pics. As badly as I'd love to have it torn off and completely replaced, I can't afford an $8,000 repair right now, period, and have no choice but to fix it up as best as I can so I can defer the full replacement for another 4-5 years.

I've gotten the impression that there's at least one repair process that's DIY-friendly, but will leave the roof in a state where it basically can't be repaired further, and nothing short of a full tear-out will be possible going forward (kind of like blowing emergency repair foam into a flat tire... it'll get you back on the road immediately, but a tire temporarily fixed with it has to be replaced because the moment you blow it into that tire, it becomes permanently irreparable). I *think* it involved a product with the word "cement" in its name, but I'm not really sure.

Keeping that in mind, is there any product available at Home Depot or Lowes that can be used to seal blisters that have been cut open and dried, and re-seal seams that are coming apart, that

a) won't render the roof irreparable going forward and mandate a complete tearout the next time the roof leaks

b) at worst, might need to be re-applied if it rains too soon after use (as opposed to, "If it rains too soon, you'll end up in worse shape than if you'd done nothing at all").

'B' in particular is vital... at this time of the year in Florida, there basically IS NO day when it truly doesn't rain at all, and you could confidently know that it wouldn't rain at all earlier in the day. A "dry" day is one with scattered light showers. A "rainy" day is one where there's a mid-afternoon mini-hurricane with 3+ inches of wind-driven torrential rain and the roads all flood...

Some roof pics taken this afternoon (1=facing west, 2=facing east, south side of roof, 3=facing east, 4=facing west, north side of roof; 5=master bathroom).

I've gotten the impression that there's at least one repair process that's DIY-friendly, but will leave the roof in a state where it basically can't be repaired further, and nothing short of a full tear-out will be possible going forward (kind of like blowing emergency repair foam into a flat tire... it'll get you back on the road immediately, but a tire temporarily fixed with it has to be replaced because the moment you blow it into that tire, it becomes permanently irreparable). I *think* it involved a product with the word "cement" in its name, but I'm not really sure.

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Huh?

Whoever told you that was smoking whacky tabaky.

You don't have a "built up" roof, which is "built up" by mopping hot asphalt onto the roof and rolling successive plies of felt paper into that hot asphalt. I think you have something called "roll roofing". However, the following repair procedure should work equally well:

The standard repair procedure for flat built-up roofs is as follows, and it doesn't "ruin" your roof:

1. scrape away the pea gravel to expose the roof membrane so that you can find the tear, crack or opening where the water is getting in. Sweep away any dust or whatever to ensure you get a good bond between the existing roof membrane and the plastic cement you'll be applying.

2. apply "plastic cement" (which you can buy at any hardware store for roofing repairs) to fill the tear, crack, or opening. Also apply it several inches around the tear crack or opening. Normally you use a "pointing trowel" to do this, but any tool that allows you to spread a coat of plastic cement without getting it all over your hands will work.

3. apply fiberglass roofing mesh over the wet roofing cement. If you can't find the stuff made specifically for roofing, then use twice as much fiberglass mesh for drywall joints. The roofing stuff is much heavier grade of fiberglass mesh.

4. apply another coat of plastic cement over the fiberglass mesh

5. repeat steps 3 and 4.

6. broadcast the pea gravel back onto the wet roofing cement to protect the plastic cement from the UV light from the Sun.

The design of the repair is very simple to understand; the plastic cement forms a water proof seal over the tear or opening in the existing roof membrane and the fiberglass mesh embedded in that plastic cement carries any tensile stress (tension) that may be in the roof membrane on cold days so that there's no tension on the patched opening so that it doesn't open again. Anything you can do to improve that design (such as using more layers of fiberglass mesh across the tear or spreading the plastic cement for a larger distance around the tear improves the repair. So you want to clean the existing roof membrane well around the tear to ensure a good bond between the old membrane and the plastic cement, you want to spread that plastic cement for a good 6 inches around the tear and you want to use at least two layers of fiberglass mesh embedded in the plastic cement.

And, if it wuz me, I would buy some pea gravel at a garden center and cover your roof repairs with that stuff to protect the plastic cement from the UV light from the Sun.

You don't have a "built up" roof, which is "built up" by mopping hot asphalt onto the roof and rolling successive plies of felt paper into that hot asphalt. I think you have something called "roll roofing".

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Hmmm. This is the first I've heard of it, but you might be right. I thought anything that involved a flat roof & asphalt-based products was a "Built Up Roof" (as opposed to SPF -- sprayed polyurethane foam, or single-layer PVC or rubber membranes). It makes sense, though... the neighbors' roofs look EXACTLY like a tile roof does before the tile goes on. It's probably just a "Dade County" thing, but down here roof tiles are regarded as little more than missiles ready to be launched by the next hurricane into your neighbor's house. Ever since Andrew, tiled roofs have to be designed so that they can be completely denuded of every last tile without losing their water resistance (based on the assumption that in a real hurricane, the roof WILL be stripped bare of its tiles before the eye even arrives at halftime.

One thing that's been bothering me ever since yesterday... is there any legal/engineering/technical reason why penetrations through concrete roof decks aren't themselves surrounded by a hollowed-out cone of low-slump concrete (kind of like a pipe emerging from the mouth of a volcano)?

To me, it seems like the best possible way to protect penetrations from water that works its way under the top layers of roofing material would be to make the top layers almost unnecessary. Form a steeply-sloping conical hilll around the entire penetration with a trowel and low-slump Xypex-enhanced concrete, and everything on top to provide further protection would practically be moot. Water flowing horizontally along the slab's surface would run into a steeply-sloping rounded surface (the cone's base) that's chemically monolithic with the slab itself (the surrounding slab would be Xypex-treated as well) and take the path of least resistance... around it. Just about the only way water could get in is if the hood were blown off, and falling rain entered from directly above.

Ditto, for the edges where the slab meets the parapet walls... trowel the same low-slump Xypex-treated concrete along the perimeter to form a sloping transition from the horizontal slab to vertical parapet walls, treat the adjacent surfaces with more Xypex, and even the complete failure of any additional roofing membrane would be of little immediate concern, because the whole roof would basically be like a shotcreted swimming pool sitting over a parking garage -- filled with water, but acting like a big pool because any water not flowing towards a drain would have no physical path into the home's interior.

The one possible problem I can think of is expansion joints. Would they be necessary at all on a 44x18 suspended slab roof deck, or is that small enough that merely isolating them from the roof slabs of neighboring units would be good enough to avoid failure due to cracks (particularly if the slab were protected by insulation and some kind of cladding, even if that cladding weren't strictly needed for water-resistance alone)?

Well, the first roofer was just here. I haven't gotten a price quote yet, but here's what I found out:

* My roof is absolutely, positively a 100% conventional oldschool hot-mopped built up roof.

* The roofer didn't want to do a complete tear-off... partly because there's no logistically good way to actually DO it. They can't park a truck alongside a corner unit, because I'd have to get permission from 3 neighbors to beat up THEIR roofs getting my own hauled away. I wouldn't want them to do it to me, and I assume they'll feel the exact same way.

- Removal via the rear is out of the question completely. The yard is walled in and covered with a screened enclosure.

- Removal via the front would entail disassembly of the pergola (not out of the question, but would likely kill an entire day if I did it myself doing it carefully so that I could put it back together again afterwards). It would also shred and destroy all the work I did back in January making the front look nice. Needless to say, I'm non-enthused about this option.

So... that basically leaves having the roofer do what I might otherwise do myself... cut, dry, and cement down the blisters and loose upper layer, prime it, cement down a layer of fiber reinforcement, then coat it with 3-5 layers of liquid elastomer.

If push came to shove, and I ended up doing the job myself, what order should I do the repairs in if there are simply too many to complete the whole job from start to finish in a single day, and it's likely to rain in between my repair days?

To help break it down, here are what I see as the main sub-areas:

a) The parapet wall tops and sides

b) The flashing between the parapet walls and roof deck

c) the front third (where ponding is the worst, there's no drain, and no positive drainage towards the rear -- where the actual gutter is)

d) the mid third (so many blisters, it's almost one big blister, plus two pairs of bath vents + stack vents (one on each side), and the air conditioner.

e) the rear third (puffy blisters along the perimeter, but all things considered, it's in visibly better shape than the mid and front thirds)

So, within those sub-areas a-e (and maybe some sub-sub areas within 'd'), what order would I:

1. slice, dry, and cement the blisters closed

2. prime

3. reinforce with fiber+elastomer

4. apply the first layer or two of heavy-duty elastomer

5. apply the finishing layer or two of white, surface elastomer

???

Put another way, would you do the steps roof-wide in order (fix all the blisters on the entire roof, then prime the entire roof, then do the fiber, etc), or would you do things a little bit out of order, like:

1. Slice, dry, and cement all the blisters along the roof's perimeter (say, within a foot of the edge)

2) Prime the parapet walls and the outer foot of the roof deck

3) apply one or more of the elastomer coats to the parapet walls ONLY

THEN

4) repeat steps 1-3 with the middle third of the roof

5) ditto, for the front third

6) ditto, for the rear third

My rationale is basically that doing the parapet walls first will get that whole sub-project out of the way, and won't substantially harm the unfixed areas of the roof in the meantime. I'd do the middle third next, because that's where I've observed outright water infiltration. This part alone will probably take me a few days to finish. Applying the elastomer to the middle first will probably worsen the ponding at the front third of the roof... but really, I don't see how it can get much worse than it already IS. Plus, I'll have a blower, so I can go up once or twice a day and blow the ponded water off. The rationale for finishing with the rear third is simply the fact that it's in the best condition of the entire roof (a few puffy blisters, but no ponding, and nowhere near as bad as the other 2/3 of the roof).

Also, keep in mind that if I do it myself, besides the rain, the amount of work I can do in any single day will be limited by the heat. Just going up on the roof this morning for 15 minutes with the roofer left me so hot and sweaty, it took nearly an hour to fully recover and feel normal again... and I dried off multiple times, changed clothes, and changed my shirt AGAIN 25 minutes later because I hadn't stopped perspiring... and I'm in fairly good shape, believe it or not. 90+ degrees at 100% humidity is brutal...

Comments?

Miamicanes:

I guess we're dealing with a difference in terminology in what is meant by "built up". It is clear to me that your roof is not made from felt paper glued together with hot asphalt because such a roof does need protection from the UV light from the Sun.

In roof shingles, the granules on the shingles serve that purpose by shading the shingle, and the amount of granules from the shingles that have collected in the evestrough is one thing to consider when assessing the condition of a shingle roof since you don't always see areas on the roof where the shingles are bare of granules.

Flat "tar and gravel" roofs, which are really asphalt and pea gravel use the pea gravel for the same purpose; to shade the roof from UV light.

On your roof, I don't see any pea gravel. "Roll roofing" is basically a large wide shingle that you roll onto the roof, but I'm not very familiar with it, or torch down roofing or any of the other single membrane roofs that are used on flat roofs. Since I don't know very much about these other kinds of flat roofs, I'm not in a position to give any sort of "expert" advice on your roof. But, in the following paragraphs I'll tell you how you can get reliable advice from a knowledgeable contractor and get the work done at a competitive rate.

I can tell you that blisters on a flat roof are an indication that the roof is nearing the end of it's life. I'm not sure it's a good idea to repair the existing roof. I think that might just be throwing good money after bad. If it were me, I'd probably try to replace the roof entirely so that the money you spend now won't commit you to continue repairing the roof so as not to lose the benefit of the money already spent. You might ask about RE-DOING the roof one third at a time, tho. That way, you're not committing yourself to an ongoing repair program.

Here's a pretty reliable way to find competent contractors that will give you both reliable advice and a reasonable price on whatever you decide to do:
Simply save your yellow pages phone book from year to year.
Anyone who's working for a roofing contractor now isn't going to start his own company until he's learned everything and made all his mistakes on his boss's customer's roofs. Only when he can see for himself that he could run a roofing company himself does he make the jump by quitting his job and start his own company. And, of course, it's not lost on him that he needs to have his new company in the yellow pages phone directory in order to get business.
So, keep the old yellow pages each year when you get new phone directories on your doorstep. By simply comparing the roofing contractors listed between this year and last year with a helper and jotting down the names and phone numbers of the companies that appear for the first time in the new directory and disappear since the last directory, you can get a pretty clear picture of who the new contractors are, who's retired, gone out of business or moved, and who's simply changed their business name for whatever reason.
Anyone starting a new company is going to play it safe. That is, they're simply going to do the best job they can for each customer they have at a competitive price. That way, if the business doesn't fly, they can't blame themselves for having charged too much, or done too little or gotten bad word-of-mouth advertising cuz of 1 and 2, or given bad advice to convince the customer to spend more or anything else within their control. They'd do exactly the same thing as you or I would; do an honest job for a competitive rate, and hope that's enough to make the business successful.

I would see if you can photocopy the Flat Roofing contractors in last year's phone directory at your local library. Certainly the new contractors who've just started into business will at least give you honest advice about what condition your roof is in and whether it's really wisest to repair it or replace it.

sorry I couldn't have been of more help in this case.

I talked to someone about the roof at a party last night. He said you're right, but not with respect to South Florida. He wasn't sure whether it was merely a norm, or an outright HVHZ (high-velocity hurricane zone) building code requirement, but down here built up roofs are usually(always?) topped with roll roofing instead of gravel. Basically, because in a hurricane, gravel on a roof turns into buckshot and causes lots of window damage to neighboring buildings. Apparently, the massive damage caused by Hurricane Wilma to some skyscrapers in downtown Miami (where Wilma's strength was nowhere near what it was in downtown Fort Lauderdale) was due to a single, relatively small building with lots of loose gravel on its roof (the window damage was almost all concentrated on a single wall of the affected buildings that faced towards the building in question). I feel sorry for that building's owner, because the businesses that had the worst damage were some of Miami's most elite & powerful law firms... he knew that at the very least, the topic of legal liability was going to come up a few hundred times at lunch over the next few weeks ;-)

So, as far as gluing down the loose flashing goes... any thoughts about Gardner Leak Stopper rubberized roof patch? Good, bad, or otherwise? Likewise, for gluing down the sliced & dried-out blisters, any thoughts on Wet-R-Dry roof cement? It's cheaper than their "Premium Roof Cement", but for some reason most of their OTHER products refer to Wet-R-Dry rather than its more expensive brother. The price difference is almost insignificant in light of the labor it's going to take to fix my roof and the importance of it not failing, so I'm trying to figure out which one might be better for this application (keeping in mind the fact that it will have at most a few hours to dry/cure before the next afternoon rainstorm).

Hurricane force winds turning the pea gravel on a flat roof into buckshot is something I hadn't considered, and it does make sense. Millions of stones going 150 mph would be dangerous to anything in their path.

Here in Winnipeg, they also sell two kinds of roofing cements; standard and premium. The only difference is that the premium sticks to wet surfaces so that you can repair a leaking roof while it's still leaking. I think what you're dealing with there with the Wet & Dry and Premium is the manufacturer wanting to keep his market share of the contractor business (where the price is the primary consideration) but maximize his income from DIY'er business, where price is of lesser concern. That is, I expect the difference between the Wet&Dry and Premium plastic cements is much smaller than the price difference between them. It's just a manufacturer trying to make more money where he can; from the DIY'ers, who, almost to a man, will pay extra for the premium, presuming there is an important difference between them.

I wouldn't be concerned about a subsequent rain. Plastic cement is water proof from the minute it comes out of the cartridge or can. Once you get a repair down, then you can pour water on it. You'd have to use a fire hose on the repair to blast away the plastic cement and mesh to cause the repair to leak. A rain won't damage the repair.

I would talk to some people down there about fixing the blisters yourself. Just cut them open with a knife of some sort, smear some plastic cement under the roofing there to get the membrane to stick down to whatever is under it, then put down three more layers of plastic cement with a layer of roofing fiberglass mesh between each layer. And, based on what you're saying about hurricanes, I'd spread some plastic cement the size of a 15 year shingle over the repair and press a 15 year shingle down into that plastic cement to protect the underlying plastic cement from the UV light from the Sun.

(I say 15 year shingle because it's the granules on the shingles that protect the underlying asphalt from the Sun, and a 15 year shingle has as many and as large granules as a 30 year shingle, so from a UV perspective, they'd offer the same protection. 30 year shingles are made from thicker asphalt impregnated paper or from two layers of asphalt impregnated paper, and you're not relying on the paper to protect against water penetration; the plastic cement does that. You're only after UV protection.)

Another option.I work at a hospital with a flat roof and I ve seen the roofs of several bussineses in my community,all roofed with 80 mil vinyl. we had a roof leak at church,some one had scraped the peagravel to try and repair the leak.I covered the are with a 10' by 40' piece of vinyl.No more leaks.I would lay it over exsisting roof.One negitive,vinyl
can be punchered but it can also be repaired easly .White vinyl will also deflect the heat.Just an opimion.good luck

Well, yesterday I spent a couple of hours up on the roof trying to patch the flashing with the obvious hole and two blisters. I came to the conclusion that there are SO MANY blisters up there, it would literally be easier to rip the entire upper layer off and replace it. Basically, every 3' x 3' area has at least one notable blister, and many of the blisters run into each other.

Then, I realized that the lower layers (hot-mopped asphalt + felt) are in nearly perfect condition (there was lots of water between the lower layers and the upper layer, but the lower layers themselves seemed to be almost flawless). It appears that my current problem is due to the penetrations being flashed to the upper layer. Water is getting under the topmost layer, running between the top layer and felt+asphalt, flowing under the flashing, then down into the hole.

It occurred to me: perhaps I could tear off the upper layer, then replace it with reinforced elastomer *instead*. Put another way, my roof would be (from top to bottom):

Ames Maximum Stretch white elastomer coating (2 coats)
Ames Super Elasto-Barrier (4-5 coats, with roof fabric embedded in layer #3)
Ames Super Primer
(existing felt + asphalt layers)
(existing insulation)
(existing vapor barrier)
(existing concrete roof deck)

I emailed Ames' tech support to ask whether it's a viable option, but don't expect to hear back from them until Monday. Intuitively, it seems like it shouldn't be merely "ok" -- really, it seems like it would be a superior option. Why? Because the elastomer would be applied to a foundation that's firmly in place and isn't going anywhere. If I apply it to a new layer of roll roofing, it will basically be resting on a layer of roofing material whose own service life is 5-10 years, max. If the roll roofing comes up, the elastomer will come up along with it. As I understand it, the asphalt + felt layer is basically what you'd end up with if you took a "conventional" built-up roof and removed 95%+ of the gravel, anyway. The lower layers would lack the physical protection of a hard "shingle-like" surface, but I'm under the impression that roof fabric embedded in Super Elasto-Barrier would be just as good, anyway.

If I do that, I'll probably just do the removal, primer, and two coats of Super Elasto-Barrier now, and embed the roof fabric and topcoat it this winter when it's not as brutally hot outside (and we can predictably have more than 12 rain-free hours in a row).

On the other hand, if they say that the roll roofing layer is absolutely essential, I'll probably just tear off the roll roofing, replace it with new roll roofing + cold-process roof cement from Home Depot or Lowes, and maybe put a coat of Super Elasto-Barrier on it for good measure. In any case, I don't think I'm going to even bother trying to cut, dry, and patch the individual blisters. There are just too many of them, with too much water trapped between the roll layer and felt+asphalt layers

The single hardest part I see is removing the old roof. I just might have to pay someone to do that, because I don't know whether I have the stamina to tear off the roll roofing from a 20x44 foot area, fix the flashing, prime it, and apply at least one layer of Super Elasto-Barrier in a single day... in 96-degree 99% humidity, no less. I know the big roofing companies won't touch a job that only involves tear-off, but maybe some of the 2-3 person small roofing companies might.

Miamicanes:

If it wuz me, I would compare this year's yellow pages listing of "Commercial Roofing Contractors" to those listed in last year's phone book and ask those new companies about just replacing the deteriorated surface layer of your roof.

I'd be reluctant about puting down any elastomeric coating on your roof. Elastomeric coatings are more meant for masonary walls with active cracks that open and close with building movement. They're water proof, but I think replacing the surface of the roof you have with the same thing, only new, would be the better option.

I wouldn't try doing this work yourself. 90% of the problems that occur around a house can be done by a DIY'er with the resolve to at least try solving the problem before giving up. Re-doing a flat roof is one of the other 10%.

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In solidarity with the freedom seeking people on the streets of Iran.

Well, I talked to the homeowner association's site manager on Saturday, and his opinion of elastomeric roof coatings was pretty high. He said that you basically need to re-coat them after every hurricane and every few years, but as long as you do that, they'll last indefinitely. The downside is that if you intend to PAY someone to do it for you, it's really expensive. The upside is that if you don't mind spending a few hours on the roof, it's easily DIY-able. Normal asphalt-based roofing is minimally (or not at all) DIY-able.

I was actually surprised by his opinion of sprayed polyurethane foam. His opinion was that it's one of the best systems if you can afford to maintain it... but said they're expensive to maintain (they need more foam added after every hurricane), and unlike elastomeric roof coatings, you can't do it yourself. He said if we get lucky and have 5-10 years without a direct hit by a major hurricane, the added insulation will easily pay for itself... but if we have another year like 2004, the roof repair costs will eat up the previous decade's worth of savings.

It's important to keep in mind that my roof differs in at least one significant way from most residential flat roofs: it's concrete. That means there's zero risk of hidden damage to the roof deck itself -- there won't ever be rotten boards, moldy plywood, or termite-weakened rafters/trusses. The roof cladding is important, but its ONLY role is waterproofing what lies below. It has zero structural value or importance. As long as it keeps water away from the roof deck and penetrations, it's done all it needs to do.

Plus, as I pointed out to my mom this afternoon, the danger of falling is minimal, because it's basically a flat slab. My only real danger is if I try to carry a 5-gallon bucket up a ladder, instead of renting a scissor lift. I might risk carrying things like a 1-gallon pail of roof cement up a ladder, but if I'm doing a full tear-off of the top layer, there will most certainly be a scissor lift present to transport the new materials up, and the old roof materials down.

I have no knowledge of polyurethane foam vis-a-vis flat roofing.

My experience with elastomeric coatings is that I heard of them and learned about them through people I know who are knowledgeable about paint. Elastomeric coatings are used on exterior walls of masonary structures to bridge any active gaps. Basically, the coating is made of the same plastic as that toy "Stretch Armstrong" so that it will stretch to cover a widening crack or gap, but will revert back to it's original shape once the gap closes back up again. I really don't know what the difference is between an elastomeric roof coating and an elastomeric coating for the exterior of a masonary building, but I'm confident that a paint-on coating won't be as durable as a built-up roof membrane like your roof originally had on it. If your homeowner's association has experience with the rooftop version of an elastomeric coating, and is impressed with it, then he has more experience with that material than I, and I would trust his assessment more than mine.

It's true that your concrete roof deck will not be affected by a leaking roof membrane. However, that concrete roof and the interior walls of your house have plaster or drywall on them, and those will be affected by water.

If you're house is only two stories, you can get by without a scizzor lift. You can use a ladder to carry 1 gallon pails of plastic cement up the ladder, but you have to have a safe and secure ladder. A SAFE and SECURE ladder is one which:

A) is tall enough that the top of the ladder is a good 5 feet or so above the elevation of the flat roof, and

B) is secured to the steel flashing (or anything else that's sturdy) on the roof edge with a bungee cord (or any other strong cord) to securely hold the top of the ladder and prevent it from moving. If your ladder has hollow rungs, then consider running a bungee cord through one of those rungs and clipping both ends on your roof's steel flashing. If the exterior of your building is brick, drill some holes in a mortar joint, insert some plastic or lead anchors, screw some eye-hooks into those anchors and hook your bungee cord onto those eye-hooks. When the roof is done, drill out the plastic or lead anchors and refill the holes with new brick mortar for an invisible repair.

You want to make sure that your ladder is high enough to COMFORTABLY step onto the roof from the ladder and vice versa. You also want to secure the top end of the ladder to something sturdy so that the ladder doesn't move. You need to do BOTH of those things to have a safe ladder.

You climb up the ladder until your entire body is above the elevation of the roof, and then step off the rung of the ladder onto the roof with whatever foot you normally step forward with, swing your body around so that your center of gravity is over the roof, and then step off the ladder onto the roof with the other foot. Similarily, when you want to come down from the roof, you step from the roof onto a rung of the ladder that's close to the same elevation as the roof, swing your body around so that it's in front of the ladder and then step onto the ladder with the other foot. That is the SAFE way to get onto and off of a roof with a ladder.

(Whenever I see newbie DIY'ers with their extension ladder just a foot or two above a roof line, I just cringe knowing what a balancing act they're going to have to do to get back onto that ladder for the trip down, and it's especially scary since I know they probably didn't secure the top of the ladder to prevent it from moving. Often, these newbies have extension ladders that will reach higher, but they simply don't know how to set up their ladder properly. It's foolish and dangerous at the same time.)

If you set up a safe ladder, you shouldn't have any trouble carrying up a gallon of elastomeric roof coating every time you go up to the roof. You can buy empty 1 gallon paint cans at many paint stores. If you can only buy the roofing materials in 5 gallon pails, separate them into 1 gallon quantities at ground level, and carry them up in smaller quantities.

Any place that sells roofing supplies will typically have a truck with a conveyor belt to deliver the materials you need to the roof.

Well, some bad news and awesome news.

The bad news: I talked to someone at the building department. He's heard of Ames Super Elasto-Barrier, and thinks it's a wonderful product. Unfortunately, Ames never bothered to get "Dade County" approval for it, so it can't be used to satisfy code requirements. Put another way, if I have a roof that's code-compliant, I can paint SEB onto it with the building department's enthusiastic blessing. However, if I rip off the Cap Sheet (I finally learned the proper term for "the sheet that forms the top layer of a South Florida built-up roof), I have to replace it with a new one, using materials that have official Notices of Acceptance by either Dade County or the State of Florida (HVHZ). So, there goes the idea of tearing off the Cap sheet and replacing it with Ames' products.

The awesome news: independently of the whole drama unfolding at City Hall, my parents decided that they didn't want me to risk heatstroke, falling, or future roof leaks (I'll argue about the last two, but won't really dispute the first... it was so brutally hot & humid on Saturday, just *being* on the roof was (literally) dizzying). So... I have 3 more roofers coming out tomorrow to give estimates... one of whom explicitly does ONLY repairs (and clarified that the scope of "repairs" includes "tear off the cap sheet, replace it , and replace/repair/improve any damaged/deficient flashing), just to ensure that I have at least one roofer coming who won't try to talk me into a complete tear-off and replacement just to make more money.

It's just a hunch, but I'm getting the definite impression that the likelihood that a given roofer is willing to repair the existing roof by tearing off and replacing the cap sheet is inversely proportional to the company's size... big corporate-type roofers have paranoid lawyers who won't allow them to do anything that's not 100% under their control, the smallest roofers don't have the equipment to DO a complete tear-off and replacement, and the happy medium lies somewhere in between... the ones big enough to be able to get the equipment they need to do the job, but small enough to be willing to let common sense rule and do a partial replacement at a competitive price if they think the lower layers of the current roof are good enough to last another 10-20 years.

It seems reasonable to me that if this "cap sheet" is the top layer of a built up roof, then it's the one that's going to deteriorate the most as a result of exposure to the Sun and the local weather.

I'd point out the areas under the blisters where you found the underlying roof membrane to be in good condition to the roofing contractors and see what they think about just replacing that cap sheet.

The top layer looks like what they call around here a "torch down" this is avalible with small granules impregnated in the surface. its not the same at all to the rolled roofing you can buy at the home center. Its good stuff - it just looks like it was sloppily applied and now leaking.

If you tear it off it will most likely take off the top layer of your built up roof if it was installed correctly (bonded with the substrate).

As for a repair? I'm not sure - when researching roofers look for someone who advertised "modified bitumen" or "torch down" or flat roofs.

Torch downs are going out of favor by some due to a high chance of fire if done unsafely. I think insurance premiums are going up for contractors who do them. Make sure your contractor is insured and trained.

My roof has more drama going on than Broadway. Out of the 3 roofers who were supposed to come give estimates today, only one showed up (I can't entirely blame the other two, though... we've had torrential downpours & thunderstorms all day, with a tornado watch from ~10am until mid-afternoon). The one who came said it's definitely not torched, looks more like it's 15-20 years old, and looks like it MIGHT have been a post-Andrew hack job by someone who either didn't know what he was doing, or knew what he was doing and just plain didn't *care* because he had another roof to do the same day (Andrew's aftermath was kind of like the Wild West + modern Chinese manufacturing rolled in one; the only thing missing was the Russian mafia, and if Andrew had been in 1994, I'm sure THEY would have gotten a piece of the action too).

Getting back to the drama. They said they can't tear off and replace just the cap sheet for building code reasons. Apparently, they can slice open most of the roof's top layer to air out the blisters, then lay down another new layer on top of it with hot-mopped tar and qualify it as a "repair", but if they go all the way and REMOVE that top layer, they'll be required to tear off and completely rebuild the entire roof regardless of the lower layers' condition because the codes were changed again in 2007, and tearing off the cap sheet would trigger the full force of the new law with no gradfathering provisions. Well, either that, or they could tear off and replace the cap sheet for 1/3 of the roof per year...

ok - so the obvious conclusion we are coming to here is the best solution is a rip out and replace. When you do that you have the advantage of being able to upgrade the insulation.

The thing that sucks is the cost. You said about $8K. That seems high but thats just a gut reaction. It may be right on the money.

So - What to do? If you know where the leak is just slop some of that roof cement on it and hope for the best. There are alos mop on coatings you can go over everything.

For a temporary repair I wouldn't worry about the "blisters". I would focus on the seams and the roof penetrations.

Then start saving. Keep an eye out for Obama money for energy efficiency upgrades. If you can get some of that we all are helping pay your roof costs! Yay.

Good luck

Actually, the one quote I've gotten so far for whole-roof replacement is $9,100. Ouch. Not to mention almost a thousand dollars more than my neighbors paid to replace THEIR roof in the aftermath of Hurricane Wilma, when roofers could charge just about anything the insurance companies would bear, 2/3 of the roofs in Broward County needed to be replaced "immediately", and we were still at the tail end of a major construction boom.

The best repair quote I've gotten so far was $3,200 to slice open the blisters, then hot tar the whole roof, put down another cap sheet on top, more tar, and fix the flashings.

One question... are exhaust vent covers flashed to the cap sheet, or are they flashed to the roof deck or one of the lower layers of the roof? I'm thinking about replacing the two I have right now with these, but need to figure out what size to buy. If the existing ones are flashed to a lower level of the roof, I'll probably just cut off their tops, and put a sufficiently-large Aura-D vent over them & flash it to the new top layer (leaving the original in place, and basically adding the Aura-D on top for extra protection. On the other hand, if they're flashed to the existing cap sheet, I'll just replace them outright.

As a junior member I recently learned I may not offer links to product sites, etc., until I've posted 5 times. This my second. Accordingly I'll only offer my generic thoughts and limited application-specific product solutions.

I reside in upstate New york where we've lived in a house attached to a flat-roofed garage, hot asphalt-mopped , for over 30 years. It's been one continuous headache. While you have your hurricane headaches, I have snow load headaches. During these 30 years , same as you, I've, slit, cemented. etc plus twice had the asphalt removed and re-layered anew, only to face problems, almost immediately.

Basically flat roofs are a disaster, UNLESS, and I'll elaborate as follows.

Unless you have 1/8" min. or 1/4" preferred taper per foot built in slope to prevent standing water. Standing puddles of water is the culprit. It seeps into the felt, the decking, the underlying supporting joists. Over time the static and live roof-load (asphalt's heavy, so is the deck, even more so the snow) imposes continual stresses on time/water-weakened joists so they deflect more and more, deeper puddles form, felt/asphalt cracks some more, etc.

The only way to have a successful flat roof is to slope it, slightly. This can be achieved with most of your present asphalt intact, or preferably removed to the deck. The latter allows you to inspect the decking and repair where necessary and helps subsequently achieve a smoother looking, lasting roof surface. The fly in the latter ointment is the hard work in removing, plus in the expense involved in proper disposal. Disposal here, in upstate rural NY, was quoted by roofing contractors, $2k-$3.5K last year, stripping labor not-included.

My 22'x36' flat roof DIY option resulted in researching a roofer's means for applying a tapered re-roofing solution, to a flat roof such as mine. The best solution appeared to be purchasing 4'x4' tapered closed-cell-foam insulation system from Bradco and attaching on top of your partially smoothed over asphalt or directly to the bared deck. Water proof the resulting tapered foam structure with cemented UV resistant rolled membrane, etc. and rest confident no puddling will reoccur. You can also over-coat with an appropriate white liquid coating to reflect heat. The closed cell foam insulation, in your case, also helps insulate the space under the roof deck. ECO friendly.

In my case I didn't go through with this approach. Admittedly was tempted by it's relatively, DIY low cost ( materials $2-$3k). But two factors ruled against it.

1. We always hated the look of the flat roof garage as attached to our gabled colonial cape.

2. The house is actually 60 years old (we're the second owners) and the originally installed joists have weakened over time and snowloads. Accordingly, I decided to bite the bullet and remedy the basic problem. Namely, "Get rid of the flat roof".

I won't elaborateon my project, since this is not an option for you. But briefly, I'm building a gabled roof over the flat roof. The trusses, bought from a local truss manufacturer, plus roof decking and shingles were paid for by the asphalt on my flat roof THAT WASN'T stripped and carted away for disposal. Now with no more rain or snow on the flat roof ceiling of my soon to be altered garage I expect those joists to have a long life.

Talk to your local roofing contractors about installing a "tapered" roof repair system. I feel it's DIY doable, since the foam panels are light and promise to be easy/fast to install (cover with a tarpaulin during rain showers prior to cementing the membrane).

For what it was worth. Hope I was of some help. Good luck.

This posting was my way of unloading my 30 years of flat roof misery brought to mind by your photos. Incidentally, we never used the flat roof for its original owner's intended purpose - namely sit and relax, reading the morning paper.