I'm almost done with my first SIP build, but need another case of adhesive.  Do you guys know of anything I can buy off the shelf that works just as well?  I'd like to finish the panels tomorrow before the next rain.

Ben

Most building supply companies, lumber yards and Home Depot carry a foam adhesive. Make sure it specifically states that it is for foam or the glue will eat your panel foam. You can also use expansion foam. Rather then use the small spray can, you might call your local insulation company and see if you could buy a 2 or 5 gallon container.

I think he means the caulk,  Any product that is elastomeric based.  You may even have to go to a paint supplier...

Maybe. I've seen 4 types of products used:

• Adhesive Foam - This is an expanding foam(from a can) with adhesive & sealing properties. This is often used to seal and connect wood/wood, foam/wood and foam/foam surfaces...
• Expanding Foam - Another expanding foam(from a can) used to fill voids...
• Construction Adhesive - From a tube, formulated to not react with EPS, used to adhere foam and wood surfaces...
• Sealant - From a tube, formulated to not react with EPS, used to seal between wood/wood, foam/wood and foam/foam surfaces. Not designed to bond or adhere.

So, it depends on the SIP manufacturer as to which type of product that they supply. I would guess that he's talking about a 'Construction Adhesive'(non foam reactive) type of product.

I went with the PL  foam adhesive.  Safe for EPS, XPS, bonds to wood and concrete.   Used 12 tubes and need another case.  Am I going through this stuff faster than I need to? 

What's your experience with the SIP tape?  Necessary?

Ben

It's become the standard for a quality installation. It's an 'insurance policy' of sorts. If you were 100% sure that all of your seams were sealed, you wouldn't need it. But since you can't see if the seams are sealed, how do you know?

JC,

Should the tape go on both sides of the joint or is it only needed on the exterior?

Larry

Larry,
In cold climates Seam Tape only goes on the interior. However, if you're in a warm climate area, that's a great question! As I believe that vapor barriers in those areas are on the exterior of a wall. So, the purpose of the tape is to prohibit moisture movement, I would think that in warm areas the tape should be on the exterior. Therefore, I will defer to someone more knowledgeable in warm climate applications.

The experts recommend that the tape is only on one side of the seam.

If I could convince you guys to go metal SIPs on the roof you wouldn't need tape, sealants, splines or cranes to set them

We are building a Passive House with SIPs which needs to be extremely tight. They too recommended SIP tape on the interior of the panels. They did however mention that it was really up to us as to which side of the panels we chose to locate our air barrier. Using it on either side seems to be acceptable as long as we are consistent.

Taking a step back and drawing a continuous red line around your entire envelope on your plans is a good way to plan the best way to construct your air barrier. The fact that OSB SIPs are a natural air barrier, especially once taped, makes this much easier.

Chad - what thickness of SIPs are you installing for a Passiv Sip Haus?