Replies

1. 
   calvin | Nov 13, 2014 06:14pm | #1

   User

   how much overhang do you have and what kind of soffit material?

   is the plan to foam beyond the plate line?

   what have been the suggested methods from your foamers?

   Thanks.

2. 
   mark122 | Nov 14, 2014 07:07pm | #2

   yeah "B" is counter

   yeah "B" is counter productive, it would allow air into your attic.  "A" should work fine if they are foaming and sealing off where you are stapling the cardboard.

3. 
   deadnuts | Nov 14, 2014 07:49pm | #3

   Either option A or B would work

   Neither will let air into the attic once your foam is sprayed over it. The advantage of F.G. batt insulation is that it may be quicker to prep with. The down side is it may be a tad more costly in terms of material and if the installer pushes it down too far you might possibly be able to see pieces of  the insulation through the venting.

   Our installer usually staples a polyehteylene baffle at eaves. This would be similar to option A you mention. However these plastic ones they use are easier to handle and quick to install. They have one that can be used to allow venting to ridge--or not--depending on how they staple it in place. It's also long enough to be easily adjusted for just about any H.A.P configuration.

   Not sure why you don't like B, but it does seem a bit crude.

1. 
   spclark | Nov 17, 2014 06:51pm | #4

   I was gonna suggest poly too..

   ... but then I scrolled down & read that last post.

   If you can easily access the space above the aluminum venting that'd be my first choice. Not sure how well-secured it'd need to be to avoid being moved during the insulation install, but maybe your contractor can direct you here?

   Anything that might absorb moisture (like cardboard, etc.) I'd try to avoid.

   Out of curiosity, how is the underside of your roof sheathing being ventilated if everything's being closed off top & bottom? I'd be worried about voiding any warranty of the roofing materials for lack of ventilation & subsequent risk of overheating come warmer weather.

1. 
   deadnuts | Nov 19, 2014 11:16pm | #7

   what's to be vented?

   He's insulationg the roof deck.  Therefore, no space exists under the shingles where overheating can occur or void shingle warranty. Also, I assume it's to code thickness where it constitutes a "hot roof" or unvented insulation application and dew points are avoided within the roof thermal envelope or assembly.

4. 
   user-3152143 | Nov 19, 2014 09:43am | #5

   So we ended up stuffing the rafter tails with fiberglass.  There were a couple/few reasons why I was concerned: moisture in the soffits; nesting; poor installation and therefor not sealing the plate.

   I think the third item is the biggest concern.  The installers wanted to drape the fiberglass over the plate and did so along an entire eave (1st day of insulating).  We ended up settling to just bring a heavy fillet of foam over the fiberglass and onto the ceiling of the 1st floor.  Generally I think it's an okay resolution however I'm not entirely comfortable with it.

   For the second day of work, I fit the fiberglass in the rafter tails outside the plate so that the foam would be able to seal the plate.  

   Thanks for all of the responses.  Their cookie management is awkward here so it took some time before I was sitting down at the computer long enough (and without other things going on) to respond.

   Cheers!

5. 
   user-3152143 | Nov 19, 2014 09:43am | #6

   So we ended up stuffing the rafter tails with fiberglass.  There were a couple/few reasons why I was concerned: moisture in the soffits; nesting; poor installation and therefor not sealing the plate.

   I think the third item is the biggest concern.  The installers wanted to drape the fiberglass over the plate and did so along an entire eave (1st day of insulating).  We ended up settling to just bring a heavy fillet of foam over the fiberglass and onto the ceiling of the 1st floor.  Generally I think it's an okay resolution however I'm not entirely comfortable with it.

   For the second day of work, I fit the fiberglass in the rafter tails outside the plate so that the foam would be able to seal the plate.  

   Thanks for all of the responses.  Their cookie management is awkward here so it took some time before I was sitting down at the computer long enough (and without other things going on) to respond.

   Cheers!