When it comes to flashing and drainage, there are a lot of products out on the market, representing all sorts of materials. We spoke with several representatives from across the industry, discussing their products as well as their thoughts on moisture management. The following are a few excerpts from those conversations.
Advanced Building Products
"First and foremost, cavity wall construction in general it's still the way to go," said Dick Lolley, president and CEO of Advanced Building Products. "It's still the preferred way to build it. For someone who's doing quality construction who is going to use a cavity wall construction the strength is excellent and the insulation value is very good.
"Once we talk about cavity wall construction, obviously water will migrate from the exterior to the interior cavity, and what do we do with it? Most people think flashing's not a bad idea.
"Copper flashing obviously you know why we love that we make it. Laminated copper flashing is easy to work with. Longevity it will last the life of the wall and my company will give you a guarantee in writing that it will last the life of the wall.
"Most brick walls today, they're looking for a 50-year guaranteed minimum many of them up to 100-year minimum on the actual brick, grout, mortar and all that stuff. If the flashing is not working, how do you fix it? It's not like a door or a window where you can pull it out; you've got to tear the walls out. That's the only way to get in there and really fix it.
"I think it all comes back to: flashing should last the life of the wall. Peel and sticks don't, PVC doesn't, and stainless will, but it's hard to work with. Copper's the one thing that they used for so long that will last the life of the wall. It's not the cheapest, but it will last the life of the masonry."
Keene Building Products
"Good quality commercial masonry construction is done at a pretty high level," said Jim Keene, president of Keene Building Products. "What I see in the majority of the mistakes is on the multi-family residential condos and townhouses, and the single-family homes. It's just a case of putting the traditional things that go in: weep vents, flashing and proper details around the windows and doors. Those are the kinds of things that don't get done properly in residential construction. There are so many residential projects that don't have flashing and don't have weep vents.
"They have so many problems in the Midwest right now, whether it's Indiana, Kentucky or Illinois. There are so many masonry problems right now, where homebuilders have a development they've done with 15 or 20 houses in it, and all the masonry has to come back off. It's not properly detailed.
"I think residential is ready to step up and do a better job with it all. They are trying much harder to get their details correct, but they have a lot more quantity.
"When it comes to cavity walls, we sell a mortar deflection product that will handle any thickness of cavity wall. We have a product that is hinged at the bottom so that it doesn't put any pressure on the outer wall. Certain products are sized to be thicker than the cavity, so they have to be stuffed inside. That extra thick material, especially in a cavity that varies in thickness, can cause masonry issues.
"The mortar deflection is just one of four products we sell for masonry drainage. We sell mortar deflection; we sell a product for full-wall rain screen; we sell a system for venting walls, which we call vent strips; and we sell weep vents. So there are four different pieces to the DriWall masonry product line."
"Delta Masonry Barrier is going into the bottom part of the wall, typically right in between the concrete floor and the masonry wall that's built on top," said Marcus Jablonka, plant manager of Cosella Dörken. "These products are waterproof materials that prevent the masonry wall or concrete foundation wall from sucking water through the capillary action, right into the block of the concrete. If you just imagine the concrete is always going to be exposed to water or to vapor from below, so it will have a certain humidity content.
"The masonry wall has little pores, and with those pores you will have a lot of capillaries, which basically suck up the water; that can be up to knee-high. You don't want that, because there's no way you can stop it afterwards; there's nothing you can apply on the outside. So that masonry barrier has to be installed right before the first masonry block goes on the concrete.
"If you look at the U.S. in areas where more masonry is being used I can't tell you a percentage but there are very few who use masonry barriers. There's no other way to prevent the capillary action from functioning unless you put a barrier in between. And people do that, and the effect is very known. A lot of good or better construction, vapor barriers are being used below the concrete slab. It would be exactly for the same purpose: to prevent humidity from weeping into the concrete. If you do that, you should do it with your wall as well, otherwise your wall will get wet.
"I think sometimes we just don't think about what's going on below grade. We think water is only coming out of the sky and we have to take care of our roof, and our sidewalls, and our gutters and whatnot, and then we don't think about what's going on with the foundation or the basement anymore. Water can actually come from all directions. Pretty much everybody knows that we should always take care of surface water and get it as far away from the house as we can. But we still need a functioning drainage system along the base of the wall, and we also need to make sure that the house is not affected by water from below."
This summer, MortarNet will introduce Total Flash, a five-foot long, all-in-one product that includes the termination bar, flashing, mortar deflection, weep hole and stainless steel drip edge.
"There are different advantages of Total Flash to different parts of the construction industry," said Earl Bickett, general manager of MortarNet.
"First, you need to understand that when an architect specifies flashing, say, on a 50-foot wall, they think it's all continuous flashing. What they're intending is that 50 feet of flashing is one piece that they unroll, because it comes in 50-foot rolls or 40-foot rolls. What they often don't know is that it's nearly impossible to have a 50-foot continuous section of flashing. And masons would say that the longest they would get is 10 feet maximum, especially if it's a peel and stick.
"What we've done is said that we'll give them sections. Since they're getting sections anyhow, we'll make them easy to handle and easy to install, and it'll go quickly so it will help bring the cost of the building down.
"Also, we have a very specified lap joint. It's a really great lap joint because it relies on a bead of caulk that will stop any water from going from one panel to the next, and if the water gets past there, there's another bead of caulk. If the water got past that, there's actually a redundant drainage strip the same drainage material that is in the lap area, and we don't think it will ever get wet, but if it got past two beads of caulk it would find that strip and drain. If it got past that, there is a third bead of caulk that sits on top of an end dam. The end dam would slightly raise the back of the flashing to create a hill or a hump and the water would drain down and out and through that redundant drainage strip.
"It's well protected. We're into that; it's what we do. We try to say, let's make this as foolproof as we can because there are so many things that can go wrong when you're building a building. Why take risks you don't have to?
"From a mason's perspective, the masons will benefit from this because the installation is faster. The feedback we've gotten from the masons who have played with this is that it would save half the time, because everything's going in at once."
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