Crawl Space Insulation

Welcome to the second Episode of the All Things "Basementy"! Video series.

In this episode, Larry Janesky, owner and founder of Basement Systems, demonstrates the best way to insulate a crawl space. He shows how to make it not only energy-efficient, but also fully protected against high humidity and the typical moisture-related problems that plague millions of crawl spaces across the U.S. and Canada.

Larry Janesky is not only a world's authority in crawl space environment, with over 30 years of experience in the field, but he is also the pioneer in the crawl space encapsulation industry, having developed the first and to date, the most advanced crawl space encapsulation system in industry: the revolutionary CleanSpace.

The insulation method recommended by Larry is basically an evolution of the CleanSpace concept -- it is an all-in-one approach that includes the crawl space into the building envelope, by completely isolating it from the outside and from the ground.
This approach offers superior thermal protection by preventing heat transfers through the walls and ground and curbing energy losses due to air leakage as well.

It is also a better alternative for most crawl spaces than to simply insulate the floor above the crawl because it provides moisture protection for the entire space, not just the floor above it.

After drainage was corrected with a crawl space drainage system and a sump pump system, the floor was covered with a drainage mat to allow the water to flow underneath and reach the drain tiles.

The walls of the crawl space were then lined with SilverGlo rigid foam boards. SilverGlo is an extended polystyrene foam board infused with graphite that helps increase the material's R-Value up to 24%. The SilverGlo is also lined with a radiant liner on both sides. This silver lining acts as a vapor barrier keeping the moisture seeping through the walls from evaporating into the crawl. Inside the crawl, the silver lining also helps reflect heat back into the space.

TerraBlock insulation boards were then used on top of the drainage mat, to prevent heat loss through the ground. The entire floor was then lined with the CleanSpace liner: a UV treated, puncture-resistant, multi-layered 20mil plastic liner with a built-in antimicrobial layer that will prevent mold growth. The clean space was then fastened to the walls and floor and thoroughly air sealed.

This homeowner now enjoys a healthier and more comfortable home: no more humidity, mold and nasty smells from the crawl space during the summer, and no more cold drafts and cold floors during the winter. His energy bills are also much lower because without losing or gaining heat through the crawl, his HVAC system works more efficiently!

Want to learn more about basements and crawl spaces? Subscribe to our YouTube channel to be notified of all the upcoming All Things "Basementy"! videos!

Contents of this video
00:00 Introduction
00:37 Why Crawl Space Insulation Improves Overall Home Health
02:18 How We Insulate the Crawl Space with SilverGlo
02:59 How We Waterproof the Crawl Space with Drainage Mat & Sump Pump
03:27 Insulating Floors with TerraBlock Foam Insulation
04:09 Sealing Your Crawl Space with CleanSpace Encapsulation

[davidmattoon]

Good thought process. One glaring issue would be to make sure to not trap your metal support columns below the vapor barrier. The bottoms will just rust right through and you’ll never see it until they fail.

[-MrRichBiker]

Oh my, what a great invention! I admire your intellectual aspect, on every solution ..wow you're amazing Larry!
Unbelievable amount of intelligence! 👍👍

[leanit]

Larry, congrats on your BAJA endeavors. I wish there was someone who offered such crawl space services in the coastal pac NW. There are contractors out in the I-5 corridor, but they all seem to avoid the coastal counties where we get 60-120 inches of rain per year. Must see the work as too over whelming where we get so much rain. Out here the crawls are horrible.

[michaeladams]

Great Video and Well Done! There must be a far less expensive way to accomplish the same effect I would think. Not all homeowners have deep pockets!

[thomasmorrison]

Several concerns here: 1) termites travel up the foam without need for termite tunnel, 2) no termite inspection gap, 3) no drain tile around perimeter of crawlspace to direct standing water to sump pump, 4) no mention of dehumidifier, 5) no real need to insulate the floor, 6) no mold remediation or removal, 7) no mention of whether new insulation installed in floor joists, 8) no tape installed around openings for supports in floor.

[twiceisluv]

That has to be the cleanest crawl space I have ever seen! the crawl spaces I've been at have dead rats and bones look like a animal have died under there it was filthy half of the crawl spaces I have worked on

[dannyyo]

4:44 the above head floor is insulated. Do you insulate between joists? Or you leave the floor not insulated. Which would make sense since you put barrier on ground

[justinbolton]

Ever crawl space I been in was cool during summer an warm during winter

[paultrigger]

There's definitely a big market for 'crawlspace encapsulation' right now. It's an incredibly expensive project to be done right in most homes, I've been quoted from a range from 7k to 12k.

[thomasmorrison]

Wouldn't the insulation on the dirt be food for mold between the clean space plastic and the insulation on the dirt? It seems like you would have mold on the insulation. I put the plastic directly on top of the dirt. The plastic has an antimicrobial additive to prevent mold from growing on the plastic.

[siskens]

I am assuming this was the standard practice back in the day but wouldn't you use spray foam on the walls for insulation and vapor barrier?

[joshuadavid]

6mil visqueen and spray foamed 15 years ago its still doing its job and im still happy

[chekadsarami]

I assume ( if not mistaken), get rid of mold then insulation. Correct?

[drasweet]

What kind of fiberglass insulation from the wood cavity is in the crawl space and is it ok to be exposed?

[mikemecklenborg]

I am looking to re insulate my crawl space. I have air vents and I live on the west side of Washington State on an island surrounded by ocean water which has a more mild temperature. My question is in the video you talk about covering these vents? If you recommend covering them then why are they even installed in the first place. Should I cover them in winter and remove them in summer? I thought they were there to keep the area aired out and dry. My house was built in 1995 so its not real old and I do have a vapor barrier on the ground. Nothing up the concrete wall from the vapor barrier to the floor insulation. I do get a little water like a puddle about 3 inches deep and 3 foot round in rainy months of October to February that ends up at one end of my crawl space but not much more unless we get a lot of rain or excessive amount of snow which is very rare. I have about a two foot drop from one side of my crawl space to the other. The low end I have about 1 foot above me laying on my back to install the insulation and on the other end I'm on my knees or even a little higher. The hanging rods that were used when my house was built were crap because a number of them bowed down and came out along with the insulation it was suppose to be holding. I have since put them back up with the same spare rods I had under there. I see there is a new style out now I might try. Do you recommend staying with the wire rods or going to twine or plastic twine/stripping to hold it up? Any help I can get would be appreciated. I need to do it myself after find it would be three times the price for material and labor. I also plan of insulating all my pipes with the foam insulation for pipes even though I have never hand anything freeze before. I am hoping to that this maybe the only time I have to do this since on average I have about 25 years left but right now still fit enough to do it myself with my son. Thanks Mike

[rickl]

So what about the 4" required to be left uncovered on the foundation wall for termite inspections and termites eating and boring through the foam. Please address that.

[softcurls]

This video suggests to close the vents in the crawlspace, but aren't the vents supposed to keep the air moving in the crawlspace and prevent moisture from settling?

[gracejoy]

Wouldn't moisture, & potentially mold, collect on the outside of the materials used in contact with the ground & walls? Could the blocks themselves slowly crumble from mold & rot while the interior stays nicely conditioned? I don't think there's a way to avoid mold all together unless the house was built to be inhospitable to it in the first place.

[marakorzen]

My family wants to refinish our hardwood floors too. Do we need to do this before installing insulation and moisture barriers?

[bikeninja]

can anyone explain to me how to build a small cabin (on peirs) yet have running water and piping (northern climate, are the only two options for this, either a foundation or crawl space???? out of the zillion construction video's, and a bazzilion cottages I drive by here, there's gotta be a way to do this, they all can't be only 3 season cottages... what am I missing?