Prevent Leaks by Replacing Roof Decking
LESLIE: Alright, our next caller has a unique situation which could be potentially dangerous. A leaky roof over an electrical fixture. Don in Colorado, welcome to The Money Pit.
DON: Thank you for having me. I appreciate you taking my call.
I’ve got a balcony, a walkout balcony, over a living space and the living space has an electrical fixture under it. And I noticed that when we have weather that hits the southern exposure the water gets behind what I believe is a little flashing and comes down through the fixture. And it’s kind of a scary situation and I’ve got a deck out on the balcony right now that’s not nailed down but I believe it’s just in place there and screwed into place with the support structure.
TOM: What is that deck surface made of? What is the impervious layer made out of? Is it built-up roof? Is it fiberglass? What is it?
DON: It’s a built-up roof but there’s something that looks like bentuthane (ph). It’s not a rolled roofing product that’s on there underneath it but it looks like it’s sealed and what they’ve done is they’ve come up against the house and kind of pushed it up in kind of a U …
TOM: Under the siding?
DON: … and then flashed – and then up under the flashing.
TOM: Mm-hmm. And you have a door there? Is it a sliding door?
DON: Well, it’s a French door and …
TOM: Alright. Well, listen. This is a really tough place. It’s a very, very difficult place to flash and it’s going to be virtually impossible for us to try to help you figure out where this leak is. What we can say is this. If you could grab a hose and try to work the different areas of this flat deck very strategically to see if you can “make it leak,” that might give you …
TOM: … a better idea. But I will say that the most common place for this is where the roof goes up under the siding and also under the door for these leaks to occur. The fact that the water’s getting into the ceiling and down through electrical fixtures; certainly that is scary; certainly it is something that’s going to require a repair not only with the electrical fixture but also if you let that water sit in that space long enough, Don, you can develop a mold problem.
TOM: So you’ve got to get to the bottom of this leak and the best way to do that is to strategically try to see if you can run some water through a hose around that deck and figure out where it’s leaking. The roofer ought to be doing this for you and trying to figure out where that leak is happening and then fixing it. I’ve seen situations like this where it just becomes almost impossible to find it and folks end up ripping out the whole deck and replacing it and if that ends up being you I would definitely not recommend a roll roof material or a modified bitumen material or a built-up material. I would only use fiberglass. A fiberglass roof deck is absolutely the most impervious way to go. You will not need a decking surface over that. It both keeps the water out and gives you a nice surface that’s non-slippery that you can enjoy.
DON: Why thank you. Where do you get a fiberglass unit like that?
TOM: It’s not a unit. It actually is built in place. What happens is the roof decking is removed. There’s fresh plywood put down and then the fiberglass is actually laid down layer up layer by a roofing specialist who knows how to do this; the same way that you would make a hull for a boat. You know, the fiberglass is put down; the resin is put down; it’s built up; the top layer has usually abrasive additives to it so you don’t slip and when it’s done you’ve got a super, super durable surface that you don’t have to worry about putting chairs on that or tables or, really, any kind of problems. If it’s done once and it doesn’t leak it’ll never leak again.
DON: OK, thank you.
TOM: You’re welcome, Don. Thanks so much for calling us at 888-MONEY-PIT.