Crawlspace / Discussions

Crawl space versus slab, which is better?

I am in the early stages of planning a new home build. Am I correct in assuming that slab on grade constuction with passive floor heating would rule out the use of a heat pump. Also I would question your depiction of crawl spaces as damp and moldy. In a previous house I built with ICF walls the crawlspace was warm and ...

Posted by Doug Bennett Jan. 5, 2025 Foundation and basement improvements 1 response

How do you do Radon mitigation when with insulating and ventilating a crawlspace?

...crawlspaces is not recommended due to the potential risk of bringing in hot humid air during the summer months where it can condense on cool surfaces. I would likely do the same if it were my place in order to reduce radon levels, but once you have take other mitigation steps It would be wise not to ventilate it, unles...

Posted by Cathy Gaskins Feb. 17, 2021 Radon in Homes - Mitigation 2 responses

How do you insulate a crawlspace with dirt floor?

...crawlspace with no Vapor Barrier….  we would very much appreciate your input and advice.  Cheers, Sal The first thing to mention is that if you have an uneven surface of solid rock in a basement or crawlspace you are at risk of radon gas contamination, so venting is good for now but I would think of a longer term solut...

Posted by sal Bellicoso Oct. 30, 2019 Crawl spaces 2 responses

What is the best way to insulate a crawlspace to keep humidity down and stop odors?

...Crawlspaces and Basements How much insulation does a basement need And for house shopping in case you ever move….Crawlspaces or Slabs, Which is Better? How to Choose the Right Rigid Foam Board What causes frost heave and how to prevent it And about venting crawlspaces, that can be a problem depending on where you live...

Posted by Dave Bell Oct. 24, 2019 Crawl spaces 3 responses

Do I need to spray foam the ceiling of my crawl space to help winterize it?

...crawlspace improvements is here – Crawl Space Insulation Tips for Insulating Crawlspaces Properly One option would be to insulate the walls and concrete slab floor with spray foam, that would act as a vapour barrier as well as air barrier and thermal barrier. It hardens enough that you can walk on it if necessary, and ...

Posted by Sheilagh Thompson Jan. 21, 2021 Crawl spaces 1 response

Should you allow air flow through a crawl space with a dirt floor?

...Crawlspaces Properly So a few questions – is it now just flat ground under the cabin? If not, now deep is it?  How much space between the dirt and the bottom of the floor joists? Is it now just uninsulated walls made of plywood?  What I’m getting at here is that it really isn’t, or doesn’t *have* to be a crawl space an...

Posted by Amber Murray Aug. 17, 2020 Crawl spaces 3 responses

How do you lower high radon levels in a basement?

I have a house to sell, I already have contract. we stayed 13 years in that home with full finished basement. In Radon test result is 7.5pCi/L . What should  we do and how much it will cost? Can you please suggest us what should be done. House is in very good condition.  Radon mitigation equipment such as passive radon...

Posted by Uma Parekh May 22, 2020 Healthy indoor air quality 1 response

What can I do to prevent mold and musty smells from a crawlspace with a dirt floor?

...crawlspace floors that are humid and moldy. The following page will help you come up with a solution - How to fix a dirt floor crawlspace and prevent mold We aren’t big fans of crawlspaces for many reasons, and a big one is the height. It is tough enough walking around hunched over, but with 2 feet yours won’t be an ea...

Posted by bonna gordy May 15, 2020 Crawl spaces 1 response

Is it ok to add insulation between joists in a crawl space?

...crawlspace.  This is in Colorado, dry climate, cold winters.  The walls of the crawlspace are insulated and the dirt floor is sealed with a vapor barrior, but my indoor floors felt cold this last winter, making my whole living space cold.   Would it be ok to add insulation between the floor joists?  Over or under pipes...

Posted by Cheryl Bottomley May 11, 2020 Crawl spaces

How do you remove water droplets from under a crawl space vapor barrier?

...crawlspace has water droplets forming under the poly vapor barrier (on the dirt side) that means that it is doing its job. Without the poly that moisture would have evaporated into the air, raising the relative humidity in your crawlspace and increasing your risk of mold forming. Here is our page all about how to insul...

Posted by Paul Racioppo Feb. 7, 2020 Crawl spaces 3 responses

How do you install your own DIY radon mitigation system?

...crawlspaces Sub-slab depressurization is a great method for radon removal, but if the basement is not finished space, one mitigation strategy is installing a dedicated HRV in the basement that is activated by a radon gas detector; that would eliminate the risk of accidentally damaging any pipes below the slab since y...

Posted by Ariel Fridman Jan. 27, 2020 Radon in Homes - Mitigation 1 response

In the winter should you heat a low/dirt floor crawl space with a furnace vent?

...crawlspace will prevent mold. But heating a dirt floor crawlspace without taking any steps towards insulating the crawlspace and creating an air seal is going to cost dearly, so there are a few things I would do first to prevent heat loss, air leakage, moisture damage and mold. This page here will have most of the answ...

Posted by janis hobson Dec. 11, 2019 Crawl spaces 1 response

Can you provide Crawlspace Insulation Design Assistance?

...crawlspace, one is to isolate it from the conditioned space of the home (insulating the floor joists as you suggest and keeping it cold) or insulating the dirt floor, and keeping the crawlspace warm so it becomes part of the conditioned space. Have you already found pages about crawlspace repair on our site? if not, st...

Posted by Randy Christensen Dec. 10, 2019 Crawl spaces 1 response

How do you insulate a crawlspace?

...crawlspace. Insulating between the floor joists is not the best way to reduce heat loss in a crawlspace as you will have created two separate environments in terms of temperature and humidity. We normally recommend insulating and sealing the crawlspace walls and floor instead, and having it moderately heated to keep an...

Posted by Drew Weistend Nov. 14, 2017 Crawl spaces 1 response