Sill gasket

user-5482467 | Posted in Green Products and Materials on December 2, 2015 02:36am

I’m in the process of ordering the mud sill gasket, but have been thrown a curve. We’re doing 2×6 framing (zone 5).

I was planning to order the BG65 from Conservation Technology but they’re backordered and won’t have it in time. They’re also almost out of the BG63.

They suggested using either a triple row of BG61 or using their BG32 drywall gasket.

I have also seen a few references here to Denarco’s SureSeal or Protecto Wrap Triple Guard.

The 1/4 x 5 1/2 in. Sureseal option is comparable cost to the BG61 option. The 1/2 in. thick option is about 50% more. The Triple Guard is about double the cost.

I haven’t seen as many references to the Denarco or Protecto Wrap options here as I have to the Conservation Technology products and wasn’t sure why.

Any thoughts on my best option?

Thanks for your help,
Alex

Answer

GBA Prime

Join the leading community of building science experts

Become a GBA Prime member and get instant access to the latest developments in green building, research, and reports from the field.

Start free trial

Replies

GBA Editor

Martin Holladay | Dec 02, 2015 03:45pm | #1
Alex,
You may be overthinking this. Ordinary closed-cell foam sill seal is inexpensive and easily available. If you use this product, the joint can be made relatively airtight after your walls and roof are up (to put some weight on the mudsill) with either caulk or a European tape.
user-5482467 | Dec 02, 2015 05:30pm | #2
Thank you, Martin. Your tape articles also mention 3M All Weather tape (8067). Do you know how that performs on concrete?

I'll look into the Siga and Pro Clima options, too.
STEPHEN SHEEHY | Dec 02, 2015 07:00pm | #3
I used the BG63 under the 2x6 sill. You really don't need the wider stuff. I think the foam is junk.
I also used a lot of the 3M 8067 tape on the house, but I would be concerned about relying on it to seal the sill, given how uneven concrete is. Plus the gasket will be cheaper especially if you are paying for labor.
Chaubenee | Dec 02, 2015 10:28pm | #4
In the past I taped that spot and also added a galvanized z flashing that covered the tape and about 3/4" of the top of foundation. It helps to keep the tape srcure plus prevents rodents from ever chewing in there if there was any kind of gap.
Expert Member

MALCOLM TAYLOR | Dec 02, 2015 11:29pm | #5
A nice thick bead of acoustic sealant at the exterior between either the concrete and the sill, or the concrete and the sheathing.