Ever seen one of these before?
You’ve probably seen them about a million times but never noticed them. Don’t worry, I never knew what they were until we moved into our house. Turns out this little guy is a vent for our pier and beam foundation – who knew??
The whole point of foundation vents is to create air flow under your house. Basically, a pier and beam foundation is constructed over bare earth that tends to continuously produce small amounts of water. Without air circulation under the house, water vapor will accumulate over time and lead to mold, wood rot and a whole bunch of other fun problems. I got to learn all about this when we bought our house.
Our foundation had 8 foundation vents – sounds like a lot, right? Well, contrary to popular belief, 8 is NOT enough (pun intended). In fact, proper ventilation requires 1 square foot of vent for every 150 square feet of crawl space – that means that a house like ours with 2,600 square feet of crawl space needs about 17 vents! Our inspector told us that we didn’t have enough vents for proper cross-ventilation, so the first thing that we did after we bought the house (other than ripping down wallpaper) was install 6 new foundation vents (like the one pictured above, which faces out onto our covered patio). I know, I know – that only gives us 14 foundation vents and we’re supposed to have 17. We’re rebels, what can I say?
Unfortunately, some damage had already been done to the joists under our house before we added the new vents. Moisture had accumulated and caused wood rot on a number of the joists that support our floors, so some of the joists had to be replaced completely. While adding the new foundation vents will keep us from having any problems with moisture in the future, the inadequate number of foundation vents, and the fact that many of them had been covered with metal plates, proved to be a bad combo for our little house.
You might be asking if you read that right – a bunch of the vents were covered up with metal plates? Yep, that’s right – the prior homeowner had screwed metal plates onto the vents to keep cold air from getting under the house during the winter to keep her house a little warmer. Turns out that’s not an uncommon practice – if you look closely at the picture of the vent above you’ll notice a screw in the middle of the vent that can be used to attach a cover onto the vent. The jury is out on whether it’s ever a good idea to cover your foundation vents – some say it keeps your house warmer in the winter because cold air isn’t getting in the crawl space, but other experts say that it’s a bad idea to cover the vents because it encourages moisture and mold growth under your house. We are a little skittish from our joist-replacement experience and now err on the side of caution by keeping our vents open year round – we just wear socks in the winter to keep our tootsies warm.
How do you guys like your foundation vents – covered, uncovered? Don’t care? What’s your stance on wearing Christmas socks after the new year? Go ahead and comment – you know you want to!
Want to find out more about keeping your home dry and mold-free? Check out this great resource from HGTV.
