spray foam insulation ?

[EVOLVO]

I'm curious how spray foam insulation works with my collar ties. Does the foam get sprayed all the way to the peak, ignoring the ties, or do I have to cover the tops of the ties so foam can be sprayed into them? The roof is fairly steep and the ties are about 8 ft. long. I can get photos if needed

 

[Chris705]

Not sure if I totally understand what you’re asking but on my foam spray install they went around my collar ties and right up to the ridge. Basically spraying the whole underside of the roof deck. I think that if you’re spraying part of the roof deck you want to do the whole deck. Otherwise you’d have to deal with venting the area above the collar ties, losing the great benefit of air sealing your entire envelope.

 

[EVOLVO]

Thanks Chris, That's exactly what I wanted answered. So if the foam goes all the way to the ridge I won't have to install gable vents? I could leave the collar ties exposed then or sheet rock them if I chose.

 

[yeldogt]

The foam follows the roof deck -- it depends on what you are putting in the space. If it's an attic and you are installing HVAC -- I stick some insulation for sound deadening. The attic becomes a conditioned space .. no VB on the ceiling.

 

[EVOLVO]

No AC, I'm in the PNW. Only heat in the winter. No storage above the CT's. Think I'll leave them exposed.

 

[Chris705]

No venting needed if foam is direct to underside of roof deck.

 

[Hollywood D]

Mine is sprayed directly to the roof deck. I don’t have any venting. Just electric heat and no a/c. I didn’t put a ceiling in.

 

[EVOLVO]

Thanks, all!!!