DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (
-   Insulation (
-   -   How to cut and seal insulation (

Mijotter 12-02-2012 09:56 PM

How to cut and seal insulation
I was wondering what you guys thought the best way to cut 2" xps rigid foam board. Tools I have at my disposal are a table saw, circular saw, jigsaw, and simple knife. Can it be scored and snapped. I just want it to be a nice clean cut no matter what it is.

Also, they are 4x8 pieces so what would be the best way to seal them together? Simply joist tape? Thank you.

Trucon01 12-02-2012 10:52 PM

I would imagine the circular saw would give you the best cut. You certainly wouldn't be able to cut a 4x8 board on a table saw...

I used Tyvek tape when I put my boards together along with PL 300 adhesive on the walls.

Mijotter 12-02-2012 11:26 PM

Yeah i realized after i typed that, that it might be abit too big for the table saw lol. Yeah I bought the PL 300 as well. How much did you use per board?

jklingel 12-03-2012 12:02 AM

saws make a lot of "dust" which blows everywhere, and static makes them a PITA to clean up. a hand saw is the best in that regard. i find that if i cut them w/ a knife on both sides, sheets snap pretty nicely & w/ little dust.

joecaption 12-03-2012 07:43 AM

I also perfure using a knife to cut it.
Just use some spray foam to fill any gaps or flaws once it's all up.
I use a cheap throw away plastic putty knife to smooth off the foam.

One other way that I did many years ago was install the blade backwards in a jig saw. It sort of melted it's way through and made almost no dust.
I've only done it that way once, and that was 10 years ago but it worked.

Mijotter 12-03-2012 06:00 PM

The dust I can deal with, just looking for which option will give me the smoothest cut.

Windows on Wash 12-03-2012 06:03 PM

Utility knife with a sharp blade works well.

Mijotter 12-03-2012 10:15 PM

Good call. I went out and got a drywall blade for my utility knife and it scored and snapped like a charm. Thanks everyone. Now for the next part. Does anyone know the cure time for PL 300 adhesive?

Mijotter 12-03-2012 11:39 PM

Actually I finally found it. 20 minutes to set and 7 days to cure...what the. Does it have to be braced against the wall for those 7 days? sheesh.

Beepster 12-04-2012 08:35 AM

I braced mine overnight. Never had a problem. Shoot out a little dab and see how hard it gets in 24 hrs. My sheets were wedged snug between the joists and floor.


Mijotter 12-05-2012 12:54 AM

So I cut, glued and placed the xps boards on 1 wall tonight. They're being braced by whatever I could find around the house lol. Should 24 hours be enough to take the braces down?

Also, How do i go about sealing the xps at the corner. I have 1 side that is cornered to concrete, it's a small indent coming in about 5 inches from the main wall(only finishing half the basement) and another corner that will take more xps on the perpendicular wall. Thanks.

Windows on Wash 12-05-2012 07:23 AM

The glue should be dry by then. Whether it holds very well is another story.

Mijotter 12-05-2012 03:03 PM

Ok good. So does anyone know how best to seal those corners in my above post?

Mijotter 12-05-2012 07:07 PM

Would just sealing it with the PL-300 caulk be adequate for the floor and corners?

Mijotter 12-05-2012 08:23 PM


All times are GMT -5. The time now is 04:08 PM.

vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

Search Engine Friendly URLs by vBSEO 3.6.1