Wood Framed crawl space with fiberglass insulation in need on crawl space encapsulation

How To Make A Functional Crawl Space Encapsulation

Learn how to stop air leaks in your crawl space and keep your house warmer in these winter months – see our quick how-to guide for a look at the best encapsulation methods.

What is a Crawl Space

If you have ever had to go under your house, you probably used your crawl space to get there. A crawl space is an empty area beneath the home that separates the home’s base from the dirt ground.

On average, crawl spaces are between one and three feet tall. It can hold all the utilities that generally go in a basement; plumbing, electrical work, insulation, and the HVAC system can all be down in the crawl space. As convenient as it is, it can be terrifying to go under there. Mold spores, animals, or insects could be crawling everywhere, and no heat stays under there when exposed. If you do not maintain the open space, it can fill up with moisture that creates mold.

Crawl spaces are also known to create drafts or currents of cool air that flow through a room. The breezes also carry mold spores, humidity, and the cold from outside. Untreated crawl spaces can put your home at risk for dry rot, mold, pests, energy deficiency, and more.

Encapsulation is necessary because it can prevent all these issues and more. When you encapsulate a space, you create an airtight barrier between your home and the dirt ground. You seal off the crawl space to prevent insects, animals, and moisture from entering. When done correctly, it keeps the air as clean and dry as possible. Although it is easier said than done, this article will outline how to encapsulate your own crawl space.

What is Crawl Space Encapsulation

To create a crawl space encapsulation system, you must add heavy-duty polyethylene barriers to cover any open or closed areas. It is crucial to cover the entire crawl space, including the floors, walls, and possibly the ceiling. To picture it, imagine lining a vast swimming pool to prevent leaks. For the best result, cover the roof of the crawl space with polyethylene as well. Sealing tape connects the heavy-duty pieces of plastic, and a dehumidifier will regulate the moisture level in the area.  

How to Encapsulate a Crawl Space

First, get rid of all the immediate concerns in the crawl space. There cannot be any draining, mold, or combustion issues. If there are inadequate draining methods, it will only trap the moisture in and create more problems. It is also essential to do a safety inspection before encapsulating the crawl space. Identify if any appliances can emit carbon monoxide; this is to prevent backdrafts of harmful chemicals from finding their way inside the home. Lastly, check for mold on the floor joists and HVAC equipment. If you find some, remove and clean it before beginning encapsulation. 

The second step is to seal floors, walls, and vents. Take a plastic vapor barrier and attach it to the foundation walls and utility equipment. Plastic, especially 6-mil polyethylene, is perfect for installation as a vapor barrier in the home. Plastic has a low permeability rating, meaning that water in a liquid or gas state cannot travel through it. Attaching a crawl space vapor barrier prevents moisture from entering the space, so you want to make sure you completely seal the area to avoid needing repairs in the future.

Check the crawl space to see if there are vents that can allow air in and out. To seal vents, you can use foam board and spray foam. The Foam board is also attached to the crawl space door for added insulation. These items can be found at hardware stores or ordered online. 

The third step is to add a thermal barrier to the walls in the crawl space. Many people opt for using foam insulation for this step, but you have options on the type you want to use. Adding a thermal barrier can prevent unwanted drafts and have a more accessible climate to control.

The fourth step is to seal everything. Seal off any gaps or cracks with spray foam. Some places to pay attention to are band joists, plumbing penetrations, wiring, and AC drain lines. You must make sure you try and seal any gaps between the crawl space and your home. Ensure you leave a continuous inspection point or an area where it is easy to check for termites or excess moisture. 

The final step is keeping the crawl space devoid of moisture. To do so, you must also install a drying mechanism. A dehumidifier will do the trick by draining any humidity directly to the outdoors. You can also buy humidity monitors, so it is even easier to keep tabs on the moisture in your home.

For crawl spaces that are under 1,200 square feet, compact dehumidifiers will do the trick. For areas larger than 2,000 square feet, you would need a larger model that requires a condensate pump sold separately. Finding a dehumidifier with humidity level monitoring would make checking the crawlspace a breeze, as it offers live monitoring and easy access.

Benefits of Crawl Space Encapsulation

Crawl space encapsulation offers many invaluable benefits. For starters, it saves you money on your energy bill. If your home is constantly cold and damp, you must run the heater for longer. Heat is not cheap, especially in the winter. You can also turn your HVAC system off more often; both combined could save you hundreds on your electric bill. 

The encapsulation also prevents mold and pests from entering the crawl space. Mold and pests love crawl spaces because they are dark, damp, and hard to access. By removing the moisture in the air, mold can no longer grow there or enter your home. The mold and mildew spores cannot access the house since all the cracks and gaps are blocked off. Pests will not be able to find a way in, preventing mice or insects from infiltrating your home. 

Lastly, encapsulating the crawl space raises the value of your home. Because it keeps your home safe and clean, many buyers would appreciate having it. Buyers are willing to spend more money on a home that seems cleaner and safer. 

If you are ever uncertain about how to encapsulate your crawl space, consult a contractor near you. They usually offer a free estimate to homeowners and give you different options to encapsulate crawl spaces. When you don’t want to do it yourself, call around to find the best deal.

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Sierra Mickael
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