Crawlspace problems often lead to energy loss and impact your home’s comfort levels if they aren’t properly insulated. However, before you can address insulation, you have to consider ventilation, as vented and unvented crawlspaces require different responses.
In the past, it was common for crawlspaces to be vented, which would lead to fewer moisture problems. However, today’s construction practices trend toward unvented crawlspaces (often through closing vents after the crawlspace completely dries up). An unvented space is easier to keep warm in the winter.
You can determine your course of insulation based on a vented or unvented space. The major components that differ are the foundation’s walls and the subfloor of the space.
For unvented spaces, seal the space and install insulation on the foundation’s walls.
Installing insulation is advantageous because you can avoid the downsides of ventilation; you don’t have to use as much insulation; and any pipe work or ducts will be housed in a warmed space (and they won’t freeze in the winter). One final bonus is that this strategy means that sealing air leaks that exist in between the crawlspace itself and the home isn’t as important.
For vented spaces, the crawlspace “roof” (or the floor of your home) should be sealed. Next, install insulation in the home’s floor joists, and secure it to the roof. The insulation should include a vapour barrier to prevent moisture problems. The floor of the crawlspace should also have a vapour barrier, with sealed seams.
Insulation is valuable in a vented crawlspace, as it is for an unvented one; however, moisture problems may arise in the future. There are also some negative considerations to take into account that insulating the space can cause:
- Insulation may become eroded over time by pests or moisture.
- To work properly, the area must be sealed, which requires maintenance.
- The entrance to your crawlspace must be via the home by way of the subfloor, or you’ll have to create an artificial, well-maintained, tightly-sealed door.
Ventilation and insulation are important factors that keep a crawlspace in good condition. The experts at Arpi’s are available for consultation.
Our goal is to help educate our customers about energy and home comfort issues (specific to HVAC systems). For more information, click here to download our free Home Comfort Resource guide.