The arrival of warm summer weather provides opportunity for fresh air through screened windows and doors. Summer breezes are refreshing. Remember to close windows and doors when outdoor humidity levels rise. Basement windows should remain closed as well to keep humid ambient air out and to prevent mold growth. Dehumidifiers and air conditioners should be evaluated for maintenance and repairs prior to operation.
Building Science Corporation is a credible resource with unbiased factual information.
BSI-027 is a fascinating examination of the prevalence of microbial growth in new buildings. This excerpt is interesting and the photographs included in the article are truly remarkable.
“Mold is pretty easy to understand. No water no mold. Any questions? Well, there are a few. For one we have more mold today, but we don’t have more water. What’s with that? We’ve always built outside out of wet stuff. Concrete comes in a big truck and we “pour it.” We put “mud” in the joints of gypsum board. That hasn’t changed. The problem is that the same amount of water we’ve always had to deal with is hanging around longer and longer in building materials that can’t take it. We have more insulation today and that reduces drying potentials because it reduces energy exchange. That is one reason we have more problems with mold today. The “more insulation” is responsible for the water “hanging around longer” part. But there is another reason—the building materials “that can’t take it” part. We used to build out of rocks and 1,000 year-old trees. Not any more and that is a big deal, as we will see.
From an engineering perspective all that mold needs is carbon—to boldly go where no mold has gone before and seek out and find carbon. But it wants the carbon in a very special form—it wants it in the form of sugar. So, all the mold wants is the carbon in sugar. Now, we don’t talk that way because we don’t want civilians to catch on. We say that mold wants the carbon in a glucose polymer called cellulose—it makes us sound smarter. So where is all the cellulose? It’s in the plant kingdom. So, all the mold wants is the carbon in the cellulose in the plant kingdom. Pretty easy so far. But there are certain rules that the mold has to follow—one of which is that the plant has to be dead first. So what do we build out of? Naturally, dead plants.1″
The NOAA website has a fresh, new, look with a lot of reliable information.
Temperatures are dropping and systems maintenance is fundamental in efficient operation. Seasonal properties should be winterized to prevent pipe breaks and winter water damage. Occupied properties will benefit from routine maintenance, filter changes as well as an examination of ducts, vents, and connections should be included. ENERGY.GOV offers tips on heat pump maintenance. Building Green also lists suggestions for winter heat pump operation.
Roof ventilation, in most instances, promotes air circulation throughout buildings contributing to healthy indoor environments and preventing material damage that can occur when warm, moist, air is trapped inside. Attic insulation is another component that creates comfort in controlling indoor conditions. More is not always better, more can be too much.
Recently, we have worked remediating building attics where excessive insulation has been installed in attic spaces, blocking attic ventilation, and preventing air circulation necessary for comfortable indoor living. Maine has had programs in place offering rebates and financial assistance for weatherization programs. The key, to making good use of the grants and low interest financing available, is hiring a reputable, qualified firm to complete improvements. Prior to hiring contractors to complete weatherization/winterization projects, ask for references, proof of insurance, proof of applicable certifications and check the Better Business Bureau for complaints. The following links provide basic information on attic ventilation published by energystar.gov and a reference manual published jointly by the U.S. Department of Housing and Urban Development and the U.S. Department of Health and Human Services.
- Perform maintenance regularly; keep a schedule for routine building examinations. Look for condensation and wet spots from the attic to the basement.
- Be certain attic soffit vents, gable end vents, and ridge vents are unobstructed by insulation and/or contents. Attics are not meant to be used for storage.
- Maintain living areas; clean kitchens and bathrooms regularly, do not allow unused organic materials to accumulate and dispose of refuse in a timely manner.
- Leave a 2-3″ space between furniture and walls allowing air to circulate freely.
- Repair plumbing leaks and other building leaks as soon as possible.
- Prevent moisture condensation by reducing the moisture level in the air and increasing air circulation.
- Keep HVAC (heating, ventilating and air-conditioning) drip pans clean, flowing properly, and unobstructed; change filters regularly.
- Vent moisture generating appliances (e.g., clothes dryers) to the building exterior (i.e., outside) when possible.
- Be sure to check water hoses on appliances e.g. dishwashers, washing machines, refrigerators/ice cube makers, as well as reviewing hot water heaters for wear and deterioration on a quarterly basis.
- Vent kitchens and bathrooms to code requirements. Exhaust ducting must discharge to building exterior.
- Leave the bathroom door open and run the exhaust fan for a few minutes after showering/bathing.
- Provide adequate drainage around buildings and slope ground away from building foundations; follow local code requirements.
- Clean gutters and downspouts; add downspout extensions to divert water away from building foundation if necessary.
- Be sure there is at least 2′ between buildings and landscaping; the gap will allow air to circulate and prevent moisture accumulation.
- Remove snow from roofs to prevent structural damage/ice dams and to keep ridge vents and DWV pipes working effectively.
- Identify areas where leaks have occurred, correct the causes and take preventative action to ensure leaks do not recur.
- Never leave buildings while appliances are running unattended.
Gardening can be a a pleasure, especially after a long winter. Thoughtful planning in horticultural pursuits will prevent water damage and ancillary building systems damage. Landscaping Network advocates caution in planting and pruning plants with runners so they do not penetrate the building envelope or invade underground utilities. Allowing 2-3 feet between foundations and plants and shrubs is advisable to allow air to circulate freely between the building and vegetation to keep the building dry. Considering all aspects in your landscape design will provide continuing enjoyment.