Why Your Home Needs Crawlspace Insulation

Why Your Home Needs Crawlspace Insulation

So you’ve contracted professionals and made sure to properly insulate most of your home. But there’s something wrong. The walls are nice and warm but the floors are unbearably cold! What happened?

It could be your crawlspace. While this part of the house is basically hidden away, it’s still as important as any room when it comes to having continuous and full insulation coverage. Crawlspace insulation is integral to make your home as comfortable and as energy efficient as it should be.



Why do you need crawlspace insulation?

So why is there a need to invest in a part of your house that no one’s ever going to see? Because without some attention a crawlspace can not only lead to uncomfortable drafts and cold feet but also moisture issues that could damage the structure of quality of your indoor air. This can seriously affect how you live.

To complement your existing insulation

A chain is only as strong as its weakest link. You need complete coverage to maximize your insulation’s many benefits. That’s because even if you’ve made sure to properly insulate the walls and the attic, you can still lose some of that heat through your floors.

A crawlspace or basement, if uninsulated, has totally unprotected walls and a moisture-rich floor. Heat energy moves from warm to cold so these cold areas essentially suck the heat away from your conditioned living space. Another concern is a concept called stack-effect in which warm air rising up and exiting your home’s upper floors and attic will be replaced by air leaking in lower in the building. This movement of air through the structure is a huge source of energy loss and contributes to uncomfortable drafts. To combat this, furnaces run longer and harder to compensate for shifting temperatures indoors. 

Houses work as a system so to perform at their best all components need to do their part. So don’t forget about what’s under your floors.

To help regulate indoor air

Bare walls inside your crawlspace aren’t airtight. They can still let unfiltered air in. It seeps through the floor, partitions and ducts and into your home’s main living space.

crawl-space-closed-cell-foam Closed-Cell Foam on Walls and Rim Joist of Crawl Space

This is contaminated air that carries allergens, moisture and other irritants which will circulate indoors. 

Insulating your crawlspace can prevent this. By making sure that the air quality is regulated beneath your house, you can be in better control of the air your family is breathing indoors. Vapor barriers and products like spray foam that work to seal and insulate help control. More on this below. The main point is that if you can contain this unwanted air movement you can be in a position to monitor and control it keeping it healthy and safe. 


To save more energy and money

Through proper insulation you’re saving energy which means lower bills. According to the US Department of Energy, crawlspace insulation is just as important as insulating the main parts of the house because it relieves some of the work that your HVAC units have to do on a daily basis. When added to your overall insulation system, crawlspace insulation can keep more unfiltered air out and maintain indoor temperatures and humidity levels. Meaning, the heating and cooling system that you have don’t have to work as hard and eat that much electricity and fuel. And with this reduction on energy consumption, you’re making your home a lot greener.

To increase your home’s market value

If you’re planning on eventually selling your home, its market value can go up when it’s well-equipped with the right insulation. That’s because most buyers today value and prefer energy efficiency. With today’s growing awareness, buyers want houses that are much friendlier to their pockets and to the environment. 

How is crawlspace insulation installed?

Tight crawl space with plumbing in the way
Tight crawl space with plumbing in the way The crawl space must be accessible to allow room to work.

There are usually two ways to approach crawlspaces. Either insulate the walls of the area or the bottom of the floor above. This depends on what is in the crawlspace and where it sits in relation to grade level of the exterior soil. Plumbing lines or heating and cooling ducts are best to be brought inside conditioned space so this means spraying the walls as first choice. If the space is empty the underside of the floor may be a good option. It’s best to consult with a trained professional to assess the dynamics of your unique situation. 

When below grade walls are being insulated, closed-cell foam is used almost exclusively due to contact of the walls with the soil outside. Closed-cell foam, also referred to as 2-pound foam, is resistant to moisture and typically qualifies as a vapor barrier at 2 inch or more thicknesses. Foams of this type have R-values near 7 per inch allowing them to pack a lot of thermal resistance into minimal thicknesses. For the Erie PA and Buffalo NY climate building codes call for R-10 on foundation walls typically. 

When insulating crawl spaces it’s important that the floor is tended to as well. That’s because water vapor from the ground underneath eases upward, entering the crawlspace and adding moisture to the area. This is addressed by placing a heavy sheet of plastic on the soil and by lapping it up the walls. When the walls are foamed we spray onto this plastic to help seal all the edges and reduce moisture intrusion. Standing water or leaks that cause running water into the space need to be addressed from the exterior such as with gutters or regrading the soil. Other drainage methods may be needed inside or out in extreme cases. Foam isn’t intended to be a water stop but closed-cell foam is an excellent drainage plane for above grade applications.   

Spray foam installer working in crawl space.
Spray foam installer working in crawl space. A roomy crawlspace.

Uninsulated crawl spaces can experience great temperature swings which can contribute to condensation and potentially damaging mold issues if they’re not taken care of. By insulating the walls the crawlspace becomes a semi-conditioned space and should not have these issues. 

The other method of spraying the underside of the floor may be an option when no ducts or plumbing run through the crawl space. If this is the chosen path open-cell foam is usually used for cost considerations. A vapor barrier on the soil below is recommended and the crawlspace is still vented to the outside. We do this so that the area doesn’t create trapped air space or dead air where condensation can occur more readily as temperatures change. 

One more point to address is with plumbing pipes in particular. Whenever adding insulation around pipes keep the pipes toward the warm side of the space and do not bury them in insulation. Surrounding pipes with insulation can actually prevent heat from reaching them and leave them susceptible to freezing.  We will box around pipes to keep the spray foam in the correct part of the floor cavity in these situations.

Open-cell-foam under floor
Open-cell-foam under floor Open cell foam under a well ventilated space.

Remember that each house is unique and may require different variations. Some depend heavily on the climate they’re situated in to decide which insulation is best. Always consult a professional about this to do it right.

We can help you!

We know that learning about crawlspace insulation can be both enlightening and stressful. That’s why we’re here to help. Our company is experienced with all types of foam and multiple insulation materials so you can get the job done well and within your budget.  

Call us at 814-898-8517 (Erie, PA) or 716-695-1010 (Buffalo, NY), and get a free no-commitment analysis from one of our experts.[/fusion_text]

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