Return to the Basements Forum | Post a Follow-Up

Pa Uniform Code for XPS Question

Posted by andrelaplume2 (My Page) on
Wed, Nov 11, 09 at 17:09

I have XPS's half my basement over the past year. I have, in part, used slotted 1.5" xps up against the concrete walls with drywall affixed directly to the fur strips that fit in the slots and hold it in place---the drywall sits flush against the XPS. These are pretty much closet areas. Other areas also have the XPS but I have framed directly up against the xps and plan on adding fg insulation after elecrical work is done. I have no vapour barrior as I understand the XPS is that.

I was about to start another area of my basement. That will have 1" xps directly applied to the walls and I will again frame against it and insulate with fg.

A new neighbor says I need to leave space between the XPS and framing (and perhaps should have left space between the XPS and drywall) OR should have plastic in between.

Thats not my understanding based on what I have read here.

Yes, I should have checked with my local zoning first I guess. I have tried to do everything 100% correctly but now fear if I call they may make me tear everything down....especially if this plastic was needed.

On the twonship website it says:

XXXXXXXX Township has adopted the Pennsylvania Uniform Construction Code and enforces same locally.

How can I tell what this construction code says about XPS installation? Anyone out there from PA who might know....if I am ok I will then go an get a permit to finish...assuming I need one for framing.


Follow-Up Postings:

RE: Pa Uniform Code for XPS Question

You're currently under the 2006 International Code. I don't believe this is on-line anywhere. Try your local reference library. However, Building Science Corp.s recommendations are usually made with reference to existing Codes. Specifically, here's what they say about foam insulation in basements.

A new neighbor says I need to leave space between the XPS and framing (and perhaps should have left space between the XPS and drywall) OR should have plastic in between.

Unless your new neighbour has a Ph.d in building science, I'll stick with Dr. Joe's recommendations! Because everyone lives in a house, everyone thinks they're an expert.

However, you are right that the local inspector might insist on a 6mil barrier to the warm side of the fg. I've been required to do that on two installations--XPS on the foundation, fg between the studs. Building Science says it's unnecessary but is of no harmful effect.

If some inspector says you have to tear off the drywall to put in the unnecessary barrier, you can still appeal to a supervisor in a pleasant manner, using Building Science materials. Remember, you catch more flies with honey than vinegar.

I see you're a sociable guy. But sometimes it's best to leave the chats to on-line!

Good luck.

RE: Pa Uniform Code for XPS Question

you really know your way around that site..I was on there a few times and never ran across that. To me the concept of the 6ml plastic makes no sense but if there is no harm I could just put it up. Of course the closet areas where I used the slotted stuff are already done and do not have plastice between the drywall that is adhered right to the slotted XPS nor are they R10 either....I think the the 1.5" xps was an R 7.5 and the drywall maybe adds an R1. Funny, I bet I still get more insulating factor here than someone who framed in front of the wall and put R13 in!

I found out area has now taken to farming out electrical inspections to a 3rd party. Hopefully they only look at 'electrical'. If I read you comment correctly perhaps I should just finish the framing and just have the electrical done and inspected and take it from leave the chats on line....knowing what I did is safe and sound.

RE: Pa Uniform Code for XPS Question

What about the fiberglass insulation? Does this have to be unfaced? Most places have only paper-faced insulation in stock. Also, does the type of drywall matter? I'm doing a similar install with 1" XPS against the wall, then a framed wall against it. I planned to put the wall tight against the XPS, but the framer did two walls already and left a half inch gap (not sure why).

RE: Pa Uniform Code for XPS Question

See page 10 in link below.

The paper facing, designed to inhibit moisture flow into the wall, will also slow the necessary drying to the interior in the portion of the basement that is above grade.

The 1/2" gap is irrelevant. Place the fg between the studs and against the XPS.

Here is a link that might be useful: Basement Insulation Systems

RE: Pa Uniform Code for XPS Question

Does the type of drywall matter?

I've only ever used standard 1/2". Here's a GW thread on paperless drywall. See link too.

It always seems to me that it would be better to cure the water problem at the source. In the case of a flood, the paperless drywall won't likely perform any better than paperfaced types.

Here is a link that might be useful: Paperless Drywall

 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!

Return to the Basements Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.

Learn more about in-text links on this page here