The Average Crawl Space Encapsulation Cost: What to Expect to Pay

Crawl space encapsulation is a great move for most people.

However, most aren’t quite sure if they need it or what the costs will be.

Fortunately, we’re here for you.

If you’re looking for a rough idea of crawl space encapsulation cost and whether or not it will end up being worth it for your home then you’re in the right spot. Read on and we’ll help you decide!

What is Crawl Space Encapsulation?

Crawl space encapsulation is similar to installing a vapor barrier, but it’s a much more intensive process.

The material laid down at the bottom of the crawl space is much thicker, often two to three times what you’ll find in a regular vapor barrier.

It’s far more than just a minor install on your floor, however. Encapsulation also covers the walls with rigid insulation designed to keep the temperature level underneath your home.

The core of a good encapsulation system is a dehumidifier, however. This will allow you to rest easy knowing that threats like dry rot aren’t sitting underneath the floorboards and losing timber to fungal threats.

In some places, you may also need a secondary drainage system installed. The form this takes depends on the contractor but the purpose is to ensure that any flooding is discarded as quickly as possible.

Finally, the vents will also be sealed to make the whole area underneath the home as far separated from outdoor conditions as possible.

What Are the Benefits?

The biggest benefit to crawl space encapsulation is that it keeps the space underneath your home dry and at an even temperature. The dehumidifier will help prevent dry rot while the thick bottom layer keeps condensation from rising up through and attacking the subfloor and supports.

You’ll also get some peripheral benefits:

  • Fewer insects
  • Warmer floors
  • Lower energy bills
  • Increased value for the home

All of these add up to make the home just a little bit better.

The peace of mind many people find, particularly in overly humid or rainy environments, is pretty much priceless.

The ability to keep pests out is a big bonus in many areas. Whether it’s poisonous spiders commonly found in crawl spaces, rodents, or even larger animals like raccoon or opossum. It depends on the area, but it can range from a minor benefit to a major one.

Since the crawl space will hold thermal energy better the rising heat can drive down heating bills quite a bit.

Encapsulation may not be life-changing, but the small convenience can add up big as time goes on.

What Am I Looking at for Crawl Space Encapsulation Cost?

The cost of crawl space encapsulation depends largely on a few key factors.

Depending on how extensive and professional the overall construction is you may be looking at anywhere from $1,500 to $15,000.

While a direct estimate will need to be made on-site by a contractor, you can begin to figure the cost pretty easily.

Floor Cover

The floor cover is generally made with 12mm-20mm  thick plastic. The vapor barrier will range from $0.50-$0.75 per square foot in most cases.

Opting for a thicker barrier will put you at the higher end of the price range but also provide a longer-lasting seal. Make sure that the company you’ve contacted is using high-quality material.

Siding Insulation

The insulation boards for the sides of the crawl space range from extremely cheap models running about $0.50 per board length to $2.00 per foot. The better stuff will last longer and create a much better seal.

Depending on the climate this is one of the critical pieces of the install, so it’s not a good place to cut corners.

Sealed Vent Covers

The sealed vent covers will cost from $15-$25 each. They’re pretty vital, so don’t try to just stick some insulation on the back if you’re doing it yourself.

These will help keep moisture out and warm air in. An improperly sealed vent can defeat the whole point of the encapsulation.

If you’re using a contractor then make sure to ask them about their policy on these. They can create large holes in the sides of the crawl space if they fail.


You need a bit more than a portable dehumidifier here. In most cases the dehumidifier installed will be run into the drainage system of the home.

These humidifiers generally cost from $750 to $1000 depending on what you need, but costs can go up if you have an exceptionally large crawl space.

Drainage System

If you need a secondary drainage system due to a high water table or just being in an area prone to flooding you’ll most likely be looking at $750-$1250. This includes the sump pump required to move the water to a proper place to drain.

Repairs of Previous Damage

Any damage already present will need to be repaired. The costs are pretty variable but on average expect to spend around $600 for normal moisture damage underneath the floor.


Labor costs will vary too much depending on the company for a reasonable estimate to be made without knowing the space underneath the home. It will always be figured into the final bid given by a contractor.

The Bottom Line

The biggest factor in how much you’ll end up spending is the size of the crawl space you’re looking to seal up.

Labor is the second biggest variable cost that you’ll be looking at.

Material prices are pretty solid but make sure to ask for an itemized bid so that you know you’re not suffering from extreme markup.

Made a Decision? Act Now!

Crawl space encapsulation costs vary depending on the contractor used and how much space needs to be sealed. On average you’ll be looking at a good chunk of change but not a prohibitive cost.

The benefits of crawl space encapsulation are pretty awesome, but it’s up to you to make the decision on whether or not it’s what you’re looking for.

If you think that it’s time to make the investment why not start looking for a local contractor now?

Adam Torkildson
Adam is a content marketer, gym rat, husband, father and entrepreneur.

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