Moisture is a homes biggest enemy in many ways and moisture cannot be prevented so we must manage it properly. The management of the moisture should rely as little as possible on human intervention and be designed into our homes systems. Some of the methods are as follows:
Moisture management starts outside the home with a simple theory, “keep the water away”! This starts with having gutters on your home, next is keeping the gutters clean. Screens or guards can help to reduce the amount of cleaning that is needed. Next is having properly located downspouts to carry the water away from the home. Do not allow the extension runoff to be obstructed by landscape edging or vegetation. Next is to have the ground around your home sloped so water runs away from the foundation, don’t allow moisture to pool around your home. If you live on a hill there may be the need for tiling or swales in the yard to be installed.
Have an annual inspection done, a good time is when your gutters are being cleaned. Check the seals around chimneys, plumbing vent pipes, and any other penetrations closely. Often small gaps develop that can easily be sealed with caulking. Valleys that are made of rolled roofing wear quickly and are susceptible to cracking and holes. Check the roofs edge for soft spots and wear, this can be a sight of problems in the attic.
By far the biggest problem found in attics is in the winter due to condensation that forms when the heated air passes through weak thermal areas of your home, enters the attic, and comes into contact with the cold roof, this causes condensation. Condensation can range from mild enough to promote mold growth to heavy enough to make it “rain” within the space. This condition also will cause ice dams to develop on your roof due to snow being melted at the top and refreezing when it makes it to the cold roofs edge. This can cause water to work back under your shingles and enter your home. The attic and roof are ideal for thermal image scanning to determine the thermal weak points which are often hidden under your existing insulation.
The crawl space is an “out of sight out of mind” location that is taken for granted, however it can be the most dangerous location in your home. Moisture problems under a home can cause very expensive damage to your home and serious health issues if the water is allowed to sit long enough. Due to many factors, moisture under a home cannot always be fully prevented, however it can be properly managed. As stated in the exterior section, keeping the water away from your home is the first part of preventing it from being under your home. Next is to take preventative measures with the ultimate goal to have a crawl space environment that closely mimics that of an unfinished basement and maintains stable temperature and humidity levels year round. This is obtained by the following steps:
1. Installation of a sump pump in the lowest area(s) of the home. Regardless of whether you have ever had excessive moisture to this level, remember you don’t monitor this space 100% of the time to be sure.
2. Having a full ground vapor barrier. If you do nothing else, this is the most important steps and is simply a heavy plastic sheet (4-6mil) spread over all open soil that is sealed to the foundation and at all the seams and penetrations. This keeps moisture vapors and other contaminants in the soil.
3. Sealing foundation vents. While this goes against conventional wisdom, it is proven that in humid climates hot moist air entering under a home will cause the moisture levels to rise, often to the point that it can “rain” under your home. The problem here unlike in an attic, is that the space will never reach temperatures in excess of 100 degrees to properly dry out. Crawlspaces tend to hold excessive moisture for long periods promoting decay, rot, and mold growth, all of which will eventually enter the living space of your home.
4. Insulating the band joist, this is the area above the foundation and below the floor which a weak thermal point. This will help to reduce condensation from developing and is the most common location for structural damage. Do not use fiberglass insulation, it acts as a sponge and holds moisture, solid board type insulation is advised.
5. Insulated your duct work. This will help in heating and cooling your home by reducing lost energy under you home and maintaining the temperature.
6. Regular inspections. Get to know the space, or have someone who does, particularly during different seasons to see how your home responds.