Hi Listmates,

I am halfway through my SIPs project in MN.  The ceilings are flat, so I did not do the SIPs roof panels to save cost.  The attic insulation is speced for 2 inches of foam with blown in cellulose on top for a total of R 50.  The foam is in and I belatedly noticed that the air chutes were installed to begin in the middle of my 8" SIPs wall panels.  That means that the outside 4 inches of SIPs panels are not insulated from the top.  I am worried that this will be a weak point in my building envelope.  I want to make the insulation company retrofit something to insulate that 4 inches of the SIPs panels that they negected to foam and insulate with cellulose.  It is quite a bummer to have good energy heel trusses and go to the expense of the 8 inch SIPs(which I love!!) and then to find a huge gap in the insulation on top of the SIPs panels.  Any advice/suggestions on how to fix this?  I meet with a rep from the insulation company tomorrow and want to have my argumemnts at hand.  The soffits are not in yet so we can get to the back side of the air chute (cardboard baffle).

Thanks for your help,

Ellen [script removed]

Ellen,

Per the drawings in the link below.......

http://arkansasedc.com/Business_Dev...CF789F.pdf

If the trusses are mounted on top of the SIP wall and extend to the outside face of the SIP wall, you should have no problem insulating and there should be no gap. Maybe you have a different configuration?

Thanks for responding Jeff.  The trusses have an energy heel, but no built in baffle.  Cardboard baffles have been installed as a backer for the sprayed in foam and to allow a 1" air channel for roof ventilation.  Unfortunately, the insulation crew installed the baffle so that the backer portion sits about 4inches from the exterior of the SIP wall and I did not catch it before they blew in the 2inches of foam that covers the ceiling.  That means that the fabulous SIP panel is not being utilized at the top- creating a gap in insulation.  There obviously is some insulation, but nowhere near the amount I have speced.  I was wondering if anyone had any ideas on how to retrofit that 4" space with foam so that the insulation goes to the end of the SIP panel.  I wanted to gather my armor of ideas before I met with the rep from the insulation company tomorrow.  I want them to fix it and not try to talk their way out of taking responsibility.

Ideas anyone?
Thanks,

Ellen

Can you have them blow in some additional closed cell foam on the outside of the cardboard baffles and on top of the 4" of SIP panel projecting outside of the existing insulation? Sort of a triangular cross section of CC foam ~4" wide and ~6" tall such that it is ~4" deep at the bottom (flush with the outside edge of the SIP panel) and gradually tapers up the cardboard baffle for ~6" height.

I think that is a good idea. I will ask the rep tomorrow if they will do that.

 

Thanks,

Ellen

Hi Listmates,

 

A follow up of the insulation issue- I met with the insulation rep yesterday, and even though they felt the insulation was adequate they agreed to build up more foam on the outside of the cardboard to cover the entire edge of the SIPs panel, still keeping the air chutes open for ventillation.  I am a happy camper with the resolution of this issue. 

 

Ellen