Topic 'Crawl Space Insulation' in forum 'Home Improvement' - dslreports.com

Re: Crawl Space Insulation

Mon, 28 Jan 2013 08:20:43 EDT

VioletVenom posted : Reference Erietech's last illustration where he denotes "crawl space insulation". The two lines he drew for that insulation and rafter insulation bisect in a soffit area. I suggested taking his rafter insulation below the top of the crawl space insulation into the soffit area.

If he had soffit vents he would want to install insulation channels first before insulating. No vents so moot point, filling in any infiltration area with insulation is ideal.

Re: Crawl Space Insulation

Sun, 27 Jan 2013 20:38:10 EDT

robbin posted :

said by VioletVenom:

In the soffit areas go below the existing insulation.

OK -- I don't understand this recommendation then. What are you suggesting based on your assumption?

Re: Crawl Space Insulation

Sun, 27 Jan 2013 20:03:43 EDT

VioletVenom posted : That's the way I read into it as well, no vents.

Re: Crawl Space Insulation

Sun, 27 Jan 2013 18:09:09 EDT

jkj860 posted :

said by Erietech:

Ok another question our house does not have soffits, how far do I put the insulation near the overhang?
»imgur.com/GYRY5g5

I'm guessing you mean your soffits are not vented. Either way, just insulate up to where the first floor exterior wall meets.
--
I know you think you understand what you thought I said, but I am not sure you realize what you heard is not what I meant. Nixon

Re: Crawl Space Insulation

Sun, 27 Jan 2013 17:58:05 EDT

robbin posted :

said by Erietech:

Ok another question our house does not have soffits, how far do I put the insulation near the overhang?
»imgur.com/GYRY5g5

I don't understand. It looks like you drew a pic with soffits and overhang but say there aren't any. Does your roof have an overhang?

Re: Crawl Space Insulation

Sun, 27 Jan 2013 17:32:57 EDT

VioletVenom posted : In the soffit areas go below the existing insulation. Above the bedroom area would ideally be insulated as well. Be a difficult area to put batts in, perhaps blown in cellulose.

Re: Crawl Space Insulation

Sun, 27 Jan 2013 17:12:36 EDT

Erietech posted : Ok another question our house does not have soffits, how far do I put the insulation near the overhang?
»imgur.com/GYRY5g5

Re: Crawl Space Insulation

Sun, 27 Jan 2013 10:40:03 EDT

VioletVenom posted : Not the best quality of images. I assume you are referring to the white foam in the background. Since it appears someone roofed over the previous exterior of the house you don't have cavities between studs to put any type of fiberglass insulation up against the habitable area of the house. Easiest thing to do would be to insulate between the rafters of the right side of the picture and leave the existing alone.

It appears someone tried to attach insulation directly to the previous exterior of the house, there in the foreground? That is what you don't want to do. Fiberglass insulation gets its insulating properties from trapping air, smashing it down defeats the purpose. Which is why you wouldn't want to remove that foam and then reinstall it back on top of fiberglass, potentially squashing the fiberglass down. Also note the paper backing is the vapor barrier, you want to install that face towards the interior conditioned space.

edit: lightened the contrast on the photo

Re: Crawl Space Insulation

Sun, 27 Jan 2013 09:51:48 EDT

Erietech posted : Sorry after I re-read my post I see where the confusion is coming from, in our we have sloped roofs, so I'm referring to the crawl space being in the attic.
I've attached a picture:
»imgur.com/w6dA9dS

Re: Crawl Space Insulation

Sat, 26 Jan 2013 22:24:41 EDT

hortnut posted : In 3 different jurisdictions, here in the PNW a vapor barrier laid on top of ground is required. Usually 6 mil black plastic.

Insulation batting was placed between the floor joists, 1 time on new construction and another on 2 renovations.

Something like this was used to keep it in place:
»www.homedepot.com/p/t/100375163/···00375163

Re: Crawl Space Insulation

Sat, 26 Jan 2013 20:14:45 EDT

jkj860 posted : I would use fiberglass insulation between the floor joists. You could use the foamboard on the foundation walls.
If you have pipes or air ducts, just insulate the walls.

Crawl Space Insulation

Sat, 26 Jan 2013 19:48:41 EDT

Erietech posted : I've been reading up on insulating attic and crawl spaces, but I have one question. The previous owner used rigid foam boards in the crawl space, I would like to put insulation down, would it be simple enough to put the insulation batting on top of the rigid foam board?
Or should I put the insulation down and the foam board on top?