crawl space insulation

winterh · 07-17-2015, 08:29 PM

Can someone recommend a local contractor who understands the proper way to insulate a crawl space. I bought a place last year with a dirt floor covered in plastic but not sealed tight. There is some insulation on the block walls but not every where. Batt insulation in the floor joists but sagging in places. I read an article about some crawl space horror stories that caused me to go under there and take a hard look. No obvious issues but definitely not done right. I have closed cell foam at home and was considering spraying the underside of the floor with that but am anxious to find out what works best.

Misha888 · 07-18-2015, 09:34 AM

and putting a foundation under it is what we did. Only real solution. It add a laundry room, a work space and a 2 car garage.

p.s. Horrible job for a contractor, no one likes a crawl space.

Quote:

Originally Posted by winterh

Can someone recommend a local contractor who understands the proper way to insulate a crawl space. I bought a place last year with a dirt floor covered in plastic but not sealed tight. There is some insulation on the block walls but not every where. Batt insulation in the floor joists but sagging in places. I read an article about some crawl space horror stories that caused me to go under there and take a hard look. No obvious issues but definitely not done right. I have closed cell foam at home and was considering spraying the underside of the floor with that but am anxious to find out what works best.

Slickcraft · 07-18-2015, 10:52 AM

When my father-in-law built our island camp in 1970 he installed regular batting under the floors. The camp is on piers and open under so the squirrels and mice had a good old time. In short order the batts were torn and falling out.

Some time later we had a 3 season porch on piers added to our then mainland house. We had batting insulation installed under the floor and then sealed in with 1/4" plywood. No gaps for mice and squirrels and no subsequent issues.

tummyman · 07-18-2015, 10:58 AM

You need adequate ventilation in the crawl space. Three years ago we had a "rat" slab poured in ours.....only 3 ft of space at the best. Got rod of the old dirt floor and plastic, etc. We use mechanics rollers to roll all around under the floor. Have lights, etc. We insulated the cement walls with 2 inch rigid insulation. Keeps it petty good in the winter. Problem with insulation on the joists is that mold will occur. We do have windows (small cellar types) that we open in the spring/summer/fall and close in the winter which provide once cross ventilation and keeps any musty smell out. Had a foundation company do the rat slab. A rat slab is just a concrete pad about 3-4 inches think..the name comes from keeping burrowing animals out.

DickR · 07-18-2015, 05:05 PM

Here is a link to a collection of links on "How to do everything:
http://www.greenbuildingadvisor.com/...-do-everything

Under "insulation" there is one:
http://www.greenbuildingadvisor.com/...ed-crawl-space

In general, vented crawl spaces don't work as well as unvented ones, as they admit outdoor moisture all the time, notably in summer. This creates musty smell and mold. A lot of what you decide will depend on how you want to use the structure now and in the future.

RUGMAN · 07-23-2015, 06:56 PM

I am in the same "boat" . A contractor recomened closed foam insulation, critters don't like it

Dad sold the C * C · 07-23-2015, 07:57 PM

My architect ( who is also a builder) said "START OVER"

.... If we wanted to make it a retirement house. Otherwise it's fine for a summer + house.

MAXUM · 07-26-2015, 11:34 AM

Quote:

Originally Posted by RUGMAN

I am in the same "boat" . A contractor recomened closed foam insulation, critters don't like it

That's interesting because I had heard that ants love that stuff from a licensed contractor. From what he told me they are putting some stuff in the foam now that is supposed to deter ants but isn't 100% fool proof.

I guess it all comes down to who you talk to... in a situation like this who is right?

SIKSUKR · 07-27-2015, 03:24 PM

When we manufactured SIPS, structural insulated panels, our expanded polystyrene foam had Borite in it for pest control. Not sure how effective it was or was not.

MAXUM · 07-27-2015, 04:49 PM

Taken from: http://www.peabuilders.com/sips-stru...ted-panels-faq

Q: Are insect infestations from ants and termites a problem with SIPs?

A: Unfortunately, termites and ants can infiltrate SIPs. Although they are no more likely to infest a SIP home than they are a traditional stick-framed home (especially since insects do not eat the foam for food), pests have been known to tunnel out foam and nest inside panels. Preventative treatments (such as borate-treated foams, topical sprays, and physical barriers) are available to deter infestation.

So far as SIP panels go if they are installed correctly - correctly being the key word - you're no better or worse off far as potential infestation. Fixing an area that does get compromised may be a heck of a challenge with SIPS seeing the way these things are put together.

07-17-2015, 08:29 PM	#1
winterh Senior Member Join Date: Jun 2009 Posts: 249 Thanks: 30 Thanked 135 Times in 62 Posts	crawl space insulation Can someone recommend a local contractor who understands the proper way to insulate a crawl space. I bought a place last year with a dirt floor covered in plastic but not sealed tight. There is some insulation on the block walls but not every where. Batt insulation in the floor joists but sagging in places. I read an article about some crawl space horror stories that caused me to go under there and take a hard look. No obvious issues but definitely not done right. I have closed cell foam at home and was considering spraying the underside of the floor with that but am anxious to find out what works best.

07-27-2015, 03:24 PM	#9
SIKSUKR Senior Member Join Date: Apr 2004 Posts: 5,075 Thanks: 215 Thanked 903 Times in 509 Posts	When we manufactured SIPS, structural insulated panels, our expanded polystyrene foam had Borite in it for pest control. Not sure how effective it was or was not. __________________ SIKSUKR

07-18-2015, 10:52 AM	#3
Slickcraft Senior Member Join Date: Mar 2008 Location: Welch Island and The Taylor Community Posts: 3,311 Thanks: 1,230 Thanked 2,099 Times in 958 Posts	When my father-in-law built our island camp in 1970 he installed regular batting under the floors. The camp is on piers and open under so the squirrels and mice had a good old time. In short order the batts were torn and falling out. Some time later we had a 3 season porch on piers added to our then mainland house. We had batting insulation installed under the floor and then sealed in with 1/4" plywood. No gaps for mice and squirrels and no subsequent issues.

07-18-2015, 10:58 AM	#4
tummyman Senior Member Join Date: Aug 2009 Location: Moultonborough Posts: 842 Thanks: 259 Thanked 687 Times in 244 Posts	You need adequate ventilation in the crawl space. Three years ago we had a "rat" slab poured in ours.....only 3 ft of space at the best. Got rod of the old dirt floor and plastic, etc. We use mechanics rollers to roll all around under the floor. Have lights, etc. We insulated the cement walls with 2 inch rigid insulation. Keeps it petty good in the winter. Problem with insulation on the joists is that mold will occur. We do have windows (small cellar types) that we open in the spring/summer/fall and close in the winter which provide once cross ventilation and keeps any musty smell out. Had a foundation company do the rat slab. A rat slab is just a concrete pad about 3-4 inches think..the name comes from keeping burrowing animals out.

07-18-2015, 05:05 PM	#5
DickR Senior Member Join Date: Apr 2008 Location: Moultonborough Posts: 753 Thanks: 4 Thanked 259 Times in 171 Posts	Here is a link to a collection of links on "How to do everything: http://www.greenbuildingadvisor.com/...-do-everything Under "insulation" there is one: http://www.greenbuildingadvisor.com/...ed-crawl-space In general, vented crawl spaces don't work as well as unvented ones, as they admit outdoor moisture all the time, notably in summer. This creates musty smell and mold. A lot of what you decide will depend on how you want to use the structure now and in the future.

07-23-2015, 06:56 PM	#6
RUGMAN Senior Member Join Date: Jul 2015 Location: weirs beach, Posts: 307 Thanks: 39 Thanked 40 Times in 33 Posts	I am in the same "boat" . A contractor recomened closed foam insulation, critters don't like it

07-23-2015, 07:57 PM	#7
Dad sold the C * C Senior Member Join Date: Feb 2014 Posts: 273 Thanks: 119 Thanked 62 Times in 40 Posts	My architect ( who is also a builder) said "START OVER" .... If we wanted to make it a retirement house. Otherwise it's fine for a summer + house.

07-27-2015, 04:49 PM	#10
MAXUM Senior Member Join Date: Apr 2004 Location: Kuna ID Posts: 2,755 Thanks: 246 Thanked 1,942 Times in 802 Posts	Taken from: http://www.peabuilders.com/sips-stru...ted-panels-faq Q: Are insect infestations from ants and termites a problem with SIPs? A: Unfortunately, termites and ants can infiltrate SIPs. Although they are no more likely to infest a SIP home than they are a traditional stick-framed home (especially since insects do not eat the foam for food), pests have been known to tunnel out foam and nest inside panels. Preventative treatments (such as borate-treated foams, topical sprays, and physical barriers) are available to deter infestation. So far as SIP panels go if they are installed correctly - correctly being the key word - you're no better or worse off far as potential infestation. Fixing an area that does get compromised may be a heck of a challenge with SIPS seeing the way these things are put together.