LVL nightmare ? | Ask Mason Knowles - SPF Consultant | Spray Foam Technical Questions and Answers | SprayFoam Magazine Q&A Forums

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eric himmer Posted: Apr 26, 2009 08:07 AM	LVL nightmare ? Mason and others, I did an estimate on a residential house with a 3,500 sf roof framed entirely with LVL's. The homeowner is a builder and has the same concerns as me with regard to poor adhesion and pulling away from the LVL waxy surface. Initially I thought he was talking about just the ridge or a couple of beams, but the whole house is LVL. I'm wondering if I should even get involved in the job to avoid future callback issues. I'll be spraying Bayseal CC 245 1.9lb. Is there a prep procedure to promote better adhesion on LVL's ? Has anyone dealt with this same situation ? And what did you or would you do ? Thanks for any input
mason Posted: Apr 26, 2009 05:07 PM	Greenbuilder, This is a question that you should address to your foam supplier. They should have a recommendation for a primer that will enhance the adhesion. Get it in writing. Then, spray a small section of the LVL (laminated veneer lumber), wait overnight and cut a sample of the foam to check the adhesion. The foam should be bonded to the laminated surface and hard to pull off, (specs of foam should still be stuck to the surface). If it comes off easy, you need to find another primer. We used to use Swifs Bond Primer. It stayed a little tacky and was great for making foam stick to surfaces that foam normally would not adhere well to (like polished aluminum, stainless steel and polyester fiberglass resin surfaces. . I don't know if they still make it. Any other suggestions on a similar product?

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Comments

eric himmer

Posted: Apr 26, 2009 08:07 AM

LVL nightmare ?

Mason and others,
I did an estimate on a residential house with a 3,500 sf roof framed entirely with LVL's. The homeowner is a builder and has the same concerns as me with regard to poor adhesion and pulling away from the LVL waxy surface. Initially I thought he was talking about just the ridge or a couple of beams, but the whole house is LVL. I'm wondering if I should even get involved in the job to avoid future callback issues. I'll be spraying Bayseal CC 245 1.9lb.

Is there a prep procedure to promote better adhesion on LVL's ?
Has anyone dealt with this same situation ? And what did you or would you do ?

Thanks for any input

mason

Posted: Apr 26, 2009 05:07 PM

Greenbuilder, This is a question that you should address to your foam supplier. They should have a recommendation for a primer that will enhance the adhesion. Get it in writing. Then, spray a small section of the LVL (laminated veneer lumber), wait overnight and cut a sample of the foam to check the adhesion. The foam should be bonded to the laminated surface and hard to pull off, (specs of foam should still be stuck to the surface). If it comes off easy, you need to find another primer. We used to use Swifs Bond Primer. It stayed a little tacky and was great for making foam stick to surfaces that foam normally would not adhere well to (like polished aluminum, stainless steel and polyester fiberglass resin surfaces.

. I don't know if they still make it. Any other suggestions on a similar product?

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