Replace Exterior Flashing to Prevent Moisture Behind Siding
LESLIE: Mike in Florida’s got a siding situation. What’s happening at the house?
MIKE: Well, I’ve got a construction issue with the way the house was constructed. The house is a two-story colonial house and the exterior has – well, it has a crawlspace and the exterior foundation are cinderblock. And then the framing of the house is a 2×4 framing so obviously there’s a ledge there on top of the cinderblock. The facing of the cinderblock has got regular brick there and then the builder basically used a piece of trim coil that was molded in a Z kind of fashion to bridge the gap where the exterior walls end and comes over the brick ledge and then comes down a little bit.
TOM: (overlapping voices) OK.
MIKE: And it’s a vinyl sided house. So the corners – I’m getting water infiltration in the corners in between the brick and the block and it’s starting to deteriorate the wood backing behind the vinyl. And so my question is – I was planning on pulling, of course, the vinyl off and pulling the trim coil off. And as I started looking at this I thought about just using a piece of flashing around all the corners. But it’s going to stop any air from flowing in between the brick and the block. And so I’m wondering is this just shoddy construction? I see a lot of houses that are being built like this; you know, cinderblock foundation with a 2×4 construction on it. And living in Florida, it’s a natural, you know, water and mold …
LESLIE: Lots of moisture.
MIKE: … moisture trap.
TOM: Well it sounds to me like there’s been a breakdown in the assembling of the siding-to-brick connection. And you are correct in that the fact that you have to open this up to try to figure out where it’s gone wrong. Now this flashing that you’re going to put in, are you considering to put metal flashing there or do you want to use one of the high-tech flashing materials?
MIKE: Well, what’s available in the high-tech? I think there’s some permeable – not permeable but a rubber type or …
LESLIE: Yeah, like rubber membrane.
TOM: (overlapping voices) Well, yeah. I mean there’s products like Tri-Flex, which is made by Grace, which is very flexible and stretchy and designed to go in odd-shaped places.
LESLIE: Mm-hmm. And it sort of moves and settles with the house as well.
TOM: Yeah. You may have [to find better luck] (ph). It’s much more forgiving than using a metal flashing.
MIKE: Yeah, and so all I do is trim the corners and then caulk or something to try to keep …
TOM: And you adhere it. Correct.
MIKE: … water from going in. Obviously, you know, the way the outside corners are on vinyl houses; there’s a big corner piece there.
MIKE: And what’s happening is that the water looks like it’s running down in the corners there and …
TOM: Yeah, it’s got to be water tight before you put the vinyl on almost.
MIKE: Yeah, yeah. And so, as far as breathing, now, in between the block and the brick, should I drill some extra weep holes around the top?
TOM: I probably wouldn’t be too concerned about it. If you wanted to you could put some weep holes in the mortar joints between the layers of the brick. But I think that the air is going to find it’s way in there anyway.
MIKE: Alright. I was just really surprised to see this after, you know, just four years or so.
TOM: Yeah, it’s disappointing but it really comes down to the labor. If it wasn’t correctly assembled this is the kind of thing that happens.
MIKE: Yeah, should have gone with a 2×6 exterior framing rather than just …
TOM: Well Mike, at least you’re well-suited to deal with it.
MIKE: Thank you very much. I’ll look it up.