Custom Homebuilder Houston Heights – wood Floor Cupping
Written for Bicycle Bungalows
Probably half of the old houses being remodeled in the Houston Heights are getting moisture in the house and the wood floors start to cup or buckle. Bicycle Bungalows, Custom Homebuilder Houston Heights notes that there are several reasons for this problem. One is that the floors are not acclimated properly prior to installation or two, there are not sufficient preventative measures taken.
To minimize the amount of moisture entering the house, Custom Homebuilder Houston Heights needs to make sure there is no standing water under the house. If the house is a brick house and it’s already pretty low to the ground it’s very difficult to raise the house up higher. One way to overcome this problem is to try to level out underneath the house and gently slope the surfaces towards a sump area where any water that goes under the house will collect. We will build out a sump using hardie board, the type of backer board they use for tile walls for showers and utility rooms; that sort of thing, and create a box just to keep the dirt from filling in the sump area. At the bottom of the sump we will install a sump pump with a float switch. This pump outlet needs to be piped to a French drain or out to the curb or someplace where it will drain away from the house. If the house is high enough to be able to add material under it, Custom Homebuilder Houston Heights will add sand to make the surface under the house higher than the surrounding surface. It is very labor intensive to shovel a lot of sand under there but it’s it’s doable.
Once the sand level is high enough, it’s best to add some sort of moisture barrier above the sand. Custom Homebuilder Houston Heights will use 6 to 8 mil poly sheeting. This is the same type of material that is underneath the concrete slabs. The sheeting comes in rolls of 100‘x 20‘. You can measure out between the piers which are generally 6 to 8 feet apart from each other; add a couple of feet and cut that off the length of the roll then it will lay out in 20 foot lengths. All of the joints and overlaps need to be taped down very well to create a moisture barrier. Along the perimeter of the house it is best to put 6 to 8 inch border of some sort of fine gravel; white rock white limestone is probably the least expensive to use. This will help anchor down the moisture barrier sheeting so it doesn’t blow away. Another good moisture barrier is to use closed cell spray foam insulation applied to the underside of the subfloor. Generally 2 inch thickness is sufficient because it’s more important to create a moisture barrier than the insulation value. We don’t lose too much heat through the floors but if we can keep the moisture and the breeze from blowing up through the floor it makes the house more comfortable in the winter.
Another thing to be concerned about is the edge of the floors. Sometimes moisture will come up through the space between the studs when there is a balloon framed houses. Frequently the space between the wall studs it’s open from under the house all the way up to the attic. There should be blocking between the studs and not be open for mice and bugs to run up inside the walls freely. Bicycle Bungalows, Custom Homebuilder Houston Heights has seen cases where moisture comes up through this gap and gets into the end grain of the floor and causes it to cup and buckle.
It’s important to make sure that there is adequate and proper venting under the house in the crawlspace. Ideally there would be openings on the sides of the house only and not necessarily from the front of the house or the back of the house. There should be enough cross-sectional venting area for the square footage of living space on the first floor that ratio should be at least at least 150 ft.² of living space per square foot of vents openings. When there are openings on all four sides the flow of air can get messed up such that there may be stagnant pockets under the house and not draw air properly across all the surfaces this airflow. That’s what helps keep the moisture content reduced under the house.
Besides closed cell spray foam under the subfloor, another way to keep the moisture from coming into the wood floors is to install a water barrier above the sub floor. Some builders will install an ice and water shield which is a roofing membrane material this is expensive and probably overkill. There are some products on the market that are less expensive at serve this purpose. If the floors are going to be glued down there’s a product called Fortane One which is one component urethane adhesive membrane specifically formulated to used as an adhesive or as a moisture vapor retarder reducing the transmission of water vapor from sub floor. Another option is AquaBar B which is the underlayment and is an extremely effective moisture vapor retarder. It consists of two layers of craft paper laminated with asphalt. AquaBar B is a non-reinforced 30/30/30 duplex type grade B paper.
Another way Custom Homebuilder Houston Heights may prevent having moisture trapped in the floors is to use a wax finish instead of the urethane finish. The problem with the urethane finish is that it prevents any moisture that is in the wood from escaping. There’s no place for it to go. The floors have a moisture barrier in the top as a so any leakage that comes from the sides or from the spill that gets within the word creates a problem for the moisture to escape. With a wax coat finish the moisture is still able to escape through the surface. The problem with a wax finish is that it requires periodic maintenance and buffing. The good news is that any scratches can be repaired periodically but the bad news is it’s probably needs to be buffed at least twice a year.