Before you make that kind of decision, you need to know more about why and how it is done. You also need to understand the pros and cons of doing so.
WHY DO IT
Green Building Advisor makes an excellent point about sealing the crawlspace. “If it’s in your crawlspace, it’s in your house,” the informational website says. Fungus, mold and home-destroying insects get their first foothold in the crawlspace. Sealing it also keeps out moisture and stops radon from getting into your home.
Bill Rose, an architecture professor at the University of Illinois at Urbana-Champaign, puts it a little more bluntly. “A crawlspace, closed or open, allows a high rate of exchange of soil gas with the house via barometric pumping, and soil gas may contain fungi and bacteria products (myco- and endotoxins), fertilizer volatiles, radon, smells, water vapor, worse stuff with ground contamination. A crawlspace is a settling cavity for dust, dirt, anything, and they are almost never swept clean. A closed crawlspace is indeed ‘a room in the house’—moreover, it is a very dirty room in the house,” he said in an interview with Fine Home Building
HOW TO DO IT
The first step is to see if the crawlspace is ventilated or unventilated. Older homes are typically ventilated. The thinking was this helped keep the ground under the house dry by allowing air flow. More recent research says a sealed crawlspace is better for a house. Most new homes have a sealed crawlspace.
If your home or building has an unsealed crawlspace you have two options.
1) Close and seal the vents. Then seal the crawlspace with insulation and a moisture/vapor barrier. If you have exposed ductwork and plumbing on the underside, this may work best because it keeps them in the protected area.
2) Insulate and seal the floor to seal out the crawlspace.
If you already have an unventilated crawlspace, it really does need to be sealed. The federal government’s Energy Star program has a full explanation, including the tools and materials you will need to seal the crawlspace.
• Protects water and HVAC equipment from the elements and they don’t have to be insulated
• None of the ventilated crawlspace problems
• Seals the rest of the building from the crawlspace contents
• The insulation can be damaged by pests
• Must be airtight
• Radon mitigation may still require a vent
If you need more information about sealing the crawlspace under your home let us know. We’ll be glad to answer all your questions.
Call the heating and air contractor at Fulford Heating & Cooling today (910) 842-6589 to schedule your next heating and air conditioning repair.