Frequently Asked Questions

Almost 100% of all existing homes built 20 or more years ago will have many leaks between the crawl space and the living quarters where mechanical penetrations have been made. These mechanical penetrations have been letting unconditioned contaminated air travel from the crawl space into the living quarters. Columbia Crawlspace eliminates these holes which increase energy, efficiency, and air quality in the home.

How does moisture get into my crawl space?

Moisture is introduced into the crawl space by 3 different methods:

  • Humid air through the foundation vents
  • Ground water intrusion (exterior drainage issues)
  • Plumbing leaks 

What happens when moisture gets into my crawl space?

Mold growth is the most common issue, Termites are also drawn to the moisture. 

Are foundation vents good or bad?

Foundation vents in the Southeast are very bad.  In the summer months humid air enters the crawl space and condensates.

Do my crawl space vents need to be opened or closed?

Closed, unless you have groundwater intrusion. 

How can I stop moisture from entering my crawl space?

Encapsulation prevents moisture from entering in vapor form.

Exterior and/or interior drains along with a good vapor barrier addresses groundwater intrusion. 

Do I need a dehumidifier?

When Columbia Crawl Space & SFI does your crawl space, a dehumidifier is typically not needed.   We will sometimes use them temporarily to rapidly get moisture levels down and then the crawl space will maintain suitable humidity levels.

Does my encapsulated crawl space need an exhaust fan? 

Yes, an exhaust fan is needed to keep contaminated air from moving upwards into the living quarters. Contaminated air may consist of mold, spores, radon, gas, or small particles of contaminated dust so you want to make sure you keep that out of your home.

Does my crawl space need insulation? 

By code, it is supposed to have insulation but there are many crawl spaces out there without it. We recommend insulation, but only on the foundation walls. The energy benefits of floor insulation are minimal, and in a vented crawl space, floor insulation eventually turns into an issue. It traps and holds mold spores, provides great bedding for mice and other pests, and becomes very contaminated over time. An encapsulated crawl space without insulation will always be better than an encapsulated crawl space with insulation.

If I have groundwater intrusion is a sump pump always necessary? 

No, a sump pump is not always necessary. Sometimes one may be able to “gravity flow” the groundwater out to the exterior and this is a much preferred method for many reasons. If one can “gravity flow” the water out, you will not need to purchase, maintain, or listen to a sump pump. You also won’t have to explain it to the next owners if you should decide to sell the home.

How much does it cost?

The cost is based on the square footage of the crawl space base area and also the square footage of the foundation walls.

If drains are needed, these are priced by the linear foot. 

How long does it take?

Typically, it takes about 3 days

If I am blowing conditioned air into my crawl space, will my energy bills go up?

Nearly all HVAC systems are oversized. Even if your HVAC system was professionally designed and sized it will usually still be oversized. Systems are sized based on the hottest day of the year, so every other day that is not the hottest day of the year the system is considered oversized. Oftentimes units will be so oversized that they simply do not come on and run long enough to adequately remove the humidity from the home, (short-cycling)in this situation. Using some of that air in the crawl space will actually cause the unit to run a little bit longer. This increases efficiency and allows the unit to perform at optimum levels. 

Are there any other benefits to encapsulating my crawl space?

Yes, it is more energy efficient, healthier and turns your crawl space into an asset when it is time to sell your home.


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We had our walk-in crawlspace encapsulated and insulated to make it clean, dry and useable for long term storage. We are delighted with the results; the space is clean, bright, temperature and humidity controlled. Mark and the guys at Columbia Crawl Space were efficient, professional and very conscientious of their work. The scheduling was flawless. The guys arrived ready to work, with all the right materials for that day and left the job site spotless at the end of the day. I would recommend Columbia Crawlspace to friends, neighbors, and family.Jill Griffin

The team at Columbia Crawlspace just completed encapsulation of my crawlspace in a new home. I believe they did an incredible job beyond my expectations for the cost. I had proposals from many different providers but Mark’s proposal was the most cost effective. What Mark proposed seemed reasonable and I think it will solve my problem without a lot of unnecessary bells and whistles the other contractors tried to sell me. Due to the care, they took to do the work, I trust Mark’s team and would do business with them again.Bob Johnson

They made the insulation phase a stress-free and the crew makes you feel at ease with honesty and professionalism. The foam products installed in my new home have given me peace of mind knowing I now have an ultra-efficient finished product. They did a great job from start to finish. The quote was very budget-friendly and the job was completed to the highest standards. Insulation is very an important part of any home, so make sure to hire professionals. Columbia Crawl Space is a cut above the rest. Five Stars! Thank you so much!Ivan Kellman