miamicanes
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- Jun 13, 2009
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I have a townhome whose roof is 18x44 feet. The roof deck itself is reinforced concrete, with built-up roof that's approximately 10 years old (according to the guy who sold the house to me last year). I've always had a major humidity problem (with 90pt/day whole-house dehu, I can get the house down to 45% when it's not raining, and 50% when it IS), but blamed the central A/C up until yesterday. Meanwhile, I've known for a few months that the upstairs bathroom has a major mold problem, which I've historically blamed on the broken exhaust fan and idiot previous owner's use of vinyl-backed wallpaper in the bathroom. I knew there was mold inside the wall where the exhaust fan was, but thought it was due to the duct being blocked and blowing hot, moist air into the wall cavity.
Well, earlier this week I started gutting the bathroom to eliminate the mold and fix everything once and for all. I got the drywall off the fan's wall, and what I found is shown in the first and last pics (the electrical box is for the light over the sink in the master dressing area on the other side). It quickly became obvious that water is coming in through the fan's vent shaft.
As of yesterday afternoon, my theory was that the duct was either missing its flashing, or had been removed entirely and roofed over (when cleaning out the duct, big chunks of tarry gravel came out). I was almost at the panic stage, because it occurred to me on my way to work that I might have actually punched a hole through a roof patch, and would have water pouring inside the next time it rained. I bought a ladder, made it up to the roof, and was simultaneously relieved and anguished by what I saw.
The good news is that the vent did have proper flashing and a cover, so if water is going to come in the next time it rains, it doesn't look like it will be any worse than it's been for the past few years. So at least I didn't escalate this from "problem needing repair" to "crisis" by cleaning out the duct.
The bad news is that the roof was under at least an inch of water nearly everywhere, and had a few large, very soggy and waterlogged blisters -- one of which was a few feet away from the duct in question. I'm now guessing that water is getting under the roofing, and making its way under the flashing to the duct... quite possibly, elsewhere in the house as well.
OK, time to discuss repair options.
I really, REALLY want to get the roof covered with sprayed-on EPS foam (the dense kind used for making ICF forms). Apparently, it's waterproof, provides just about the best insulation you can get, and "maintenance" consists of having more foam sprayed on if something like a hurricane or damage from the rooftop A/C's replacement dislodges chunks of it. The problem is, I've NEVER been able to get one of the few companies in Broward County with web sites claiming to do EPS roofing to ever return a call, and have a hunch that this might be one of those things that's a nearly ideal solution for flat concrete roofs... but cost-prohibitive unless you're talking about something like a multi-acre roof on a mall, plaza, school, etc.
Does anyone have any idea how the cost of EPS compares to alternatives, like IB (PVC) or conventional BUR?
Alternatively, if EPS is do-able, but way more than I can afford right this minute (or can't be done in the summer when it rains nonstop), do I have any viable DIY options that are likely to patch it well enough to eliminate the leaking for at least a few months (if I can do EPS in January or February when there's no rain) or a couple of years (when I'll be in a better financial position to afford EPS, even if it IS hideously expensive)?
The biggest problem I see right now with trying to patch it myself is the endless daily rainstorms we'll be having until November or December. The only idea I've come up with so far is to try and use sandbags to dam off a 10x10 area at a time, try to keep that area covered with plastic , and try fixing it a piece at a time, starting with the center and working my way towards the front and rear (there's a slight slope downward towards the front and rear, where there are drains emptying into gutters). I'm aware that elastomeric paint exists, but I'm not sure whether they can be applied anytime over the next few months due to the endless rain -- even if I WERE able to partly dry off a 10x10 area at a time.
Any ideas? The one bright spot here is that I DO have a concrete roof deck, so if I can at least somehow seal off the roof penetrations, I'll be 99% of the way "home". In fact, one Idea that occurred to me (no idea about cost effectiveness) was to strip the BUR altogether, build concrete "islands" around the penetrations, coat the entire roof (including the inside of the penetrations with Xypex (a concrete waterproofer that gets soaked up into the concrete matrix, then chemically bonds with any water that gets through to form crystals that physically block the passage of more water), fill the voids inside those penetrations with expanding foam sealant, and finish by painting everything with 2 or 3 coats of elastomeric paint. In theory, it seems like it would work... but I've never heard of anyone doing it, and suspect there's probably a good technical reason why (or possibly a building code requirement that this solution elegantly engineers an alternative solution to solve the original problem, but wouldn't be allowed just because that's the way the law is written).
Well, earlier this week I started gutting the bathroom to eliminate the mold and fix everything once and for all. I got the drywall off the fan's wall, and what I found is shown in the first and last pics (the electrical box is for the light over the sink in the master dressing area on the other side). It quickly became obvious that water is coming in through the fan's vent shaft.
As of yesterday afternoon, my theory was that the duct was either missing its flashing, or had been removed entirely and roofed over (when cleaning out the duct, big chunks of tarry gravel came out). I was almost at the panic stage, because it occurred to me on my way to work that I might have actually punched a hole through a roof patch, and would have water pouring inside the next time it rained. I bought a ladder, made it up to the roof, and was simultaneously relieved and anguished by what I saw.
The good news is that the vent did have proper flashing and a cover, so if water is going to come in the next time it rains, it doesn't look like it will be any worse than it's been for the past few years. So at least I didn't escalate this from "problem needing repair" to "crisis" by cleaning out the duct.
The bad news is that the roof was under at least an inch of water nearly everywhere, and had a few large, very soggy and waterlogged blisters -- one of which was a few feet away from the duct in question. I'm now guessing that water is getting under the roofing, and making its way under the flashing to the duct... quite possibly, elsewhere in the house as well.
OK, time to discuss repair options.
I really, REALLY want to get the roof covered with sprayed-on EPS foam (the dense kind used for making ICF forms). Apparently, it's waterproof, provides just about the best insulation you can get, and "maintenance" consists of having more foam sprayed on if something like a hurricane or damage from the rooftop A/C's replacement dislodges chunks of it. The problem is, I've NEVER been able to get one of the few companies in Broward County with web sites claiming to do EPS roofing to ever return a call, and have a hunch that this might be one of those things that's a nearly ideal solution for flat concrete roofs... but cost-prohibitive unless you're talking about something like a multi-acre roof on a mall, plaza, school, etc.
Does anyone have any idea how the cost of EPS compares to alternatives, like IB (PVC) or conventional BUR?
Alternatively, if EPS is do-able, but way more than I can afford right this minute (or can't be done in the summer when it rains nonstop), do I have any viable DIY options that are likely to patch it well enough to eliminate the leaking for at least a few months (if I can do EPS in January or February when there's no rain) or a couple of years (when I'll be in a better financial position to afford EPS, even if it IS hideously expensive)?
The biggest problem I see right now with trying to patch it myself is the endless daily rainstorms we'll be having until November or December. The only idea I've come up with so far is to try and use sandbags to dam off a 10x10 area at a time, try to keep that area covered with plastic , and try fixing it a piece at a time, starting with the center and working my way towards the front and rear (there's a slight slope downward towards the front and rear, where there are drains emptying into gutters). I'm aware that elastomeric paint exists, but I'm not sure whether they can be applied anytime over the next few months due to the endless rain -- even if I WERE able to partly dry off a 10x10 area at a time.
Any ideas? The one bright spot here is that I DO have a concrete roof deck, so if I can at least somehow seal off the roof penetrations, I'll be 99% of the way "home". In fact, one Idea that occurred to me (no idea about cost effectiveness) was to strip the BUR altogether, build concrete "islands" around the penetrations, coat the entire roof (including the inside of the penetrations with Xypex (a concrete waterproofer that gets soaked up into the concrete matrix, then chemically bonds with any water that gets through to form crystals that physically block the passage of more water), fill the voids inside those penetrations with expanding foam sealant, and finish by painting everything with 2 or 3 coats of elastomeric paint. In theory, it seems like it would work... but I've never heard of anyone doing it, and suspect there's probably a good technical reason why (or possibly a building code requirement that this solution elegantly engineers an alternative solution to solve the original problem, but wouldn't be allowed just because that's the way the law is written).
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