"Fighting the Winter Chills - Which is Better - Sealing Your Crawl Space or Heating It?"," Those of us who have a crawl space underneath part of our home have felt plenty of chilly floors and drafts on our ankles.
But in fact sealing and insulating your crawl space will not only resolve your indoor problems with cold floors and drafts, it will also avoid problems such as mold and rot in the space itself, and will make your whole home healthier.
For decades, homeowners, homebuilders, and building inspectors have believed that a space needs to have exterior venting on opposite walls, so that air can flow from one vent to the other, drawing out any extra humidity from the enclosed space.
In a nutshell, with a good supply of outside air from your crawl space, with a few cracks or hair's width openings between the crawl space and the upstairs, and a few drafts at the top of the house, such as old windows or a poorly sealed attic hatch, and your house starts acting like a giant chimney stack.
As a result, the cold and humidity (and mold spores and dust) from the crawl space get drawn into your home, increasing your heating costs and endangering your well-being.
Even in warm weather, when there is no vertical air flow drawing cold air up into your house and hot air out the upstairs, ventilating both ends of the space doesn't actually do much for airflow or humidity.
And the ventilation approach really amounts to addressing the symptoms - and not very well at that - instead of curing the illness.
You might find that your builder disagrees with the idea of sealing and insulating a crawl space.
But you'll improve the quality of your inside air, cut heat loss, and resolve any problems with moisture, mold, or rotting wood down below, if you set this out-of-date belief aside and go with what the research suggests is most effective.
Also, you'll be installing a plastic vapor barrier on the floor and you don't want any sharp objects to pierce through the liner and wreck it as you are installing it.
You'll need thicker than the 6 mil usually used for a vapor barrier - you should get 15 or 20 mil thickness if you want a liner that will last.
The best way to figure out the size is to add twice the wall height to both the width and length of the floor, and then add 10% extra to account for any rises or dips in the floor plus any measurement errors.
It's better to waste a little extra liner than to find yourself having to cut and tape on small pieces when you discover you didn't get enough to begin with!
Seal any ventilation openings, and for crawl space windows, either upgrade them to energy efficient windows, or at least ensure that they are not a source of drafts.
Also check that any doors to the outside are also properly weatherstripped.
Be sure that any large gaps in the walls are patched first - any place where you can see outdoor light shining in from the outside.
Trim the excess folded triangular pieces off where the wall corners meet.
Don't skip part of this job.
And do it all within a week or two - don't make this one of those home renovations that drags on for months or years.
Your floors will be warmer and less drafty, and your home will be safe from the health effects of crawl space mold and mildew.
And remember the notion we started with, that a crawl space heater might cut the cold on your floors during this cold spell? Well, if you follow the guidance above, you won't need such a heater.