Your Northern Home: crawl spaces in Southeast Alaska 

Amazing work guys and the only good referencing information I could find for my 1890 house crawled space. Continue your good work and thank you again.

This is the most detailed video I have seen regarding how to properly seal crawl spaces. Even though I don't live in Alaska we still have moisture issues and this video helps a lot. Thanks!!

Great video guys much appreciated. I live north of Minnesota and I am having issues with my crawl space. This helps big time

Seal, encapsulate & spray foam then condition the air in the space...the difference is MASSIVE. Our home in Canada burned down but when rebuilding we kept the crawl space wall foundation. 4" foam block under concrete in the floor, 6mil poly between with curtain up walls, then the walls spray foamed & all vents closed up. A dehumidifier draining into the sump pit (with lid) & a return to the heating for the home. The home has a Panasonic air exchange heat recovery unit in the entry way. It is warm, dry, cheap to heat & moisture controlled.

Good content. Your vid is perhaps to educate people who have potential to improve their house air and comfort. The vid also shows places for a builder to target as they do new construction. Thx.

This is the best video i have seen to explain the HOW and the WHY of insulating a crawlspace. I'm in BC and this info is very helpful. Especially love the discussion of options and why certain choices are the right ones for a situation. Appreciated the steps. My home exterior is fraughtwith problems and I see that sloping is where to start for now.

Good work guys! Made me want to get in there and do it too! Got a bum leg, but I can do it.

Currently neck-deep in re-insulating my vented crawlspace in Ketchikan, AK. Found lots of problems with improper batt installation of insufficient R-value, lack of sealing around subfloor penetrations and ZERO insulation around my heating ducts or water pipes, all of which I've fixed. I was glad to find something addressing our unique weather and moisture issues. I had seen other recommendations about insulating and sealing the rim joist cavities and it seems like a moisture trap but if it's already code in Juneau, I guess it will be ok here too.

Again, great video. Thanks for posting

I really needed some guidance in this area. Thank you so much for the video 😊

Very neat and informative video. Thank you.

Gracia amigos. Thank you my friends this video is really helpful. I have alot work to do now.

This video rocks. Thank you!

Informative video. Thank you

It is good to see information specifically addressing SE Alaska. This is probably the hardest conditions any building material will ever see. Moisture is a quick killer of all organics. I thought current IRC did not allow exposed foam board? The thinking being it is a fire hazard. Along that line of thought would a 10 mil Epdm sheeting (pool liners are a good source) be better than 6 mil visqueen both for durability as well as fire? It would surely be more resistant to rocky soil puncture. A sharp look tears poly and it deteriorates with time. Also having dead air (no fan under 60%) in dry periods like winter cold spells would mean a drop in temperature in the crawl space. Does that threaten the water and heating pipes? Finally, I would like to see a proven procedure for post and beam foundations. I am worried that cutting air movement will promote rot. You make the valid point that the concrete is drying to the inside with no outside release in the wet soils. As you "dry" up the surface you raise the differential humidity pressure on the sill plate etc. Won't that supersaturate the plate and speed up rot? The moisture would find some way to vent the pressure I would think, maybe through the sill plate up the rim joist? I would think leaving some outside exposed above grade would be a good path if you seal inside? Even treated rots quite well in SE. Will a good natural cross flow (1000'/vented by 12 sq. ft.) be beneficial in the warm weather (above forty) rather than always using a fan. I close off my crawl space in the winter and have seen no adverse effects in 25+ years with the floor uninsulated and a pretty porous perimeter foam board insulation installation. Despite the fact the lowest corner during heavy rain would be wet under the vapor retardent. Getting that poly to seal while you are crawling on it can be very frustrating. Thanks for an informative video dealing with SE. Doug in Ketchikan

Excellent answered alot of questions

Thank you for the excellent presentation. I live in Chicago and we have a much easier environment, but the same rules still apply. Hard to find solid building science for cold climates

Great detail. Thank you.

Very informative video thank you guys

Amazing video! Thanks!

Very helpful info...thanks.

Nice work guys.

That last place was my old house! I rented that space for 6 years on Stephen Richards!

I don't live anywhere near Alaska, but my crawlspace has the same issues you touch on in this excellent video. I have regular water infiltration, high water table, neighbour's land draining onto mine, block construction, etc. My main question is this- how do you decide whether or not to insulate the walls and not the "ceiling", or the ceiling but not the walls? Do the pipes not freeze with uninsulated walls? Should the crawlspace be heated? I hope you can respond! Excellent, detailed video!

Awesome vid guys! Even 7 yrs later lol

Great video. How does this design change if it’s a seasonal cottage/cabin that does not get consistent use? Ie, visiting infrequently in winter and warming by wood heat only. Thanks!

Very informal!

You gentlemen sound like solid, knowledgeable professionals that really know your stuff! I could surely use your guidance in knowing exactly how to go about making my crawlspace a healthy, energy-efficient, temperature-controlled environment! You wouldn't know someone in the Chicagoland area that you'd highly recommend that can assess and render service that meets YOUR HIGH-QUALITY STANDARDS, would you?

Wouldnt a dehumidifier work instead of mechanical ventalation. Would need mantenence and checking with both.

Regarding the exhaust fan. So it’s reducing the pressure in the crawl. Where don’t think the make up air is coming from? And what is the relative humidity of that make up air? The answer will vary from house to house I realize. Folks, much heavier material is available than 6 mil visqueen. I suggest using as thick a material as u can afford.

Is there a battery operated fan. Instead of a electrical one. Incase your away for the winter seasons?

@16:00 on the insulation, what R value did yo use? Is it always best to use faced for vapor barrier in cold climates?

If you are pulling air out of a sealed space wouldent it create a vacuum

Seems to me the interface between the wood rim joist and the solid insulation would condense as well. And that spray foam would act as a sponge too, no? And what are the long term consequences of keeping the concrete or block constantly wet? Won't that accelerate its deterioration?

Would spray floaming the sub floor be preferable to the fiberglass bats + foam boards, assuming cost is not an issue?

How does the fan circulate air through the crawlspace with only an exhaust? You only say it blows it to the outside but you've sealing everything. Isn't that just going to make a negative pressure but not really move any air?

with the mechanical vent wouldnt you need some sort of return air?

Mine looks like that.. shoud i use paper faced insulation and face the paper towards the ceiling?

Should the fan run 24/7 12 months or just in winter ❄️

If the water table is high, why not put in a french drain system and do a complete encapsulation project? I would think in colder climate areas, a sealed crawlspace with a dehumidifier would be the best option to keep the house warm and dry.

Can you please guide me what I should do. I have a 1,144 square foot with a cement crawl space. What should I do to prevent moisture buildup. He also put open vents 6x12 inches about 3 of them. Not sure to do since he is no longer available

The dark fiberglass is from mold, dampness or condensation. How do you know that condensation will not happen with the 2" foam board, and the foam board will how that condensation in place and not allow the rim joist to dry from the inside, creating rot that you will never see? Would you put 2" foam board on the inside of an interior wall??

XxxWhy did you not go higher on the vapor barrier

I live at White Bird ,Idaho 100+ yr old home, stone and pier open foundation, no wall insulation. I question the effectiveness. Ov negative ventilation of crawl space do to My wet soil . Our indoor humidity is usually very low. Positive psi ventilation to crawl space inside seems more practical as well as eliminating Radon gas.

A dehumidifier would have been a much better option. Air sealing then sucking air out makes no sense. If you set up a sump pump and a dehumidifier, you dont need the floor insulated, like the second house you showed. They didn't completely seal it still. I can see light behind you.

Vapour barrier should have been fitted as one piece, not bodged together as several small pieces. I don't care if it is hard to fold, do it properly.

I have a suggestion: Brick and mortar.

why not pull air out of the attic and blow it down into the crawl space all year around

Seams like you guys try to do good job, but really should just foam spray it.

no wonder it never dries up - there is no air circulation.

Metal Containers Building houses out of metal containers would be great in cold climates where there is harsh weather, beastly animals and people that harm families. I'm thinking way up north, the outskirts of where hardly anyone lives. Building structures from metal containers can be painted with special paint, solar powered and generated and also have a pump house for water. Structures built out of metal would help keep people safer, and if built off the ground in case of areas where theres flooding. I know I would feel safer if I had to live in areas where it's not close to cities/towns and where theres been wild animals looking for food. I bet if a metal container had a glass roof that caught lots of sun, perhaps built into the ground to help contain warmth, it could be used as a green house as well.

Moisture will get up in there

To all the people busting on this video how they didn't do anything right , film your own and post it if your that dam smart.