People have been putting stucco exteriors on houses for hundreds of years and the basic combination of sand, cement and lime hasn’t varied much over the centuries.

Video Transcription

Michael: It’s time to put the exterior on the project house and our Mediterranean design will be complemented perfectly by the classic look of stucco. People have been putting stucco exteriors on houses for hundreds of years. And the basic combination of sand, cement and loin has a very much over the centuries. But now the sto Corporation has come up with some improvements. Now, we’re using a special stuccos system on the project house that has reinforcing fibers and silicon enhancements to really make it a very durable light weight system. Normally you go about three quarters of an inch thick with the stucco. We’re going about 3/8 of an inch. So it’s not a lot of weight on the walls but it can take a lot of impact. So we’re going to have a great looking house for the lifetime of this home. The stucco system we’re using is called power wall. It’s a one coat system that consists of the stucco itself, thinner primer, thinner finished over the top. Paul Dixon of sto is the power wall product manager. Paul: Well, a nice feature about stucco is you have a lot of versatility in your design. You can do a lot of things and you can see in this house that you have some nice trim work. You can make rounded sections like this house. This is actually a very complex design and you’re able to do that with stucco. Michael: The installation starts when the crew places metal lath over the house wrap on the exterior wall. This type of wrap is specifically designed for use with the stucco exterior. The texture surface reduces the chance of cracking, helps the stucco cure, and channels moisture away from the wall. The lath is designed for a specific use too. Paul: The lath has a diamond shape to it. It has to be attached on a certain direction so the stucco actually gauges into the lath, part of it goes through to the other side. And that’s actually what holds the stucco to the building. Michael: The lath is applied from the ground up, with each new layer overlapping the one below. The workers simply trim around any electrical outlet or other external fixtures. Once the house is completely covered with lath, the crew begins applying the first coat called the scratch coat. The metal strips are called expansion joints. The wood and other materials beneath the stucco are constantly expanding and contracting. And the expansion joints absorb that movement. This helps relieve the strain on the stucco to prevent cracking. Traditional stucco application required the application of a ground coat as a base layout. Then a scratch coat on top of that. But this sto power wall system combines those two steps into a one coat application. Because the stucco is enhanced with polymers and fibers, no ground coat is necessary. Now you see why this is called the scratch coat. This rough texture will provide a good surface for the next coat to bond to. Once the scratch coat is dried, the crew comes back to apply what’s called the brown coat. The crew applies this coat evenly all over the surface of the house right on top of the scratch coat. Once the brown coat is applied, it needs to cure for seven to 10 days. Expanded polystyrene sections are used for exterior window trim and under the solvates. Once the trim is installed, the stucco is applied right onto the surface. Now it’s time to apply the finish coat. When creating this finish coat, sto came up with a formula that has some extraordinary features. Paul: This finish has what’s called the silicon enhancements in the formula the mix and what that does? It creates sort of a shield on the outside. Dirt will not stick to it if the water will run off so you don’t have the chance of water sticking to it holding mildew growth. Every time it rains, it washes the dirt off. This finish is also what’s called elastomeric, in other words it’s like an elastic band or rubber band around the building. It moves with the building if there’s any expansion or contraction the finish goes with it. Stucco is a cement-based product. Any type of cement-based product has a tendency to crack. If you have a finish that is elastomeric or stretches with the building, it bridges over the cracks. That way you don’t get moisture in the building. You can see its flexibility. You can roll it, movement all you want. And you don’t get any cracking. If this were a hard acrylic type finish or even just painting over stucco, you would tend to get some cracking if you tried to do this. This is actually the finish that’s on this house and you see again it can move and it’s very pliable. Michael: The installers use a texturing trout to create the finish. Then all that’s left to do is add a few final touches and we have a gorgeous stucco exterior that’s going to last a lifetime. For more information on beautiful long lasting stucco exteriors for your new house, visit sto’s website stocorp.com