Pole Barn Sill Plate - air seal

[mattlikesbikes]

We will be starting interior framing in the next week. Metal should go up today.

I am doing bookshelf girts, where the bottom one will be treated.

6x6 posts, for the girts I was going with 2x4, but for the bottom plate should I do 2x6? I will be foaming, so 2x4 would let me foam between the metal and sill. we are using 2" CCF.


Since there is no stud weight on the sill with girts, should I nail down the sill? keep it sealed tight?

Speaking of seal, what should I use? Seen a mix of remarks on foam gasket, gasket + Caulk, Caulk, fancy gasket, etc

This is TX, but an area that gets a lot of spring fog and humidity. The slab is on top of a pretty tall (12-32") gravel pad, so high and dry. But lots of bugs out here at the ranch.

 

[PugetDude]

I'd use the spray foam with the bittering agent that critters won't eat- they'll chew up a gasket, and it would take a lot of caulk to seal them out.

 

[tonyciambrone]

Matt Risinger just showed a detail like this in one of his videos. FWIW he uses foam will gasket with a bead of acoustic/elastomeric sealant on each side.

expanding foam is hard to get right in a space that small, out of a can anyways.

 

[mattlikesbikes]

Matt Risinger just showed a detail like this in one of his videos. FWIW he uses foam will gasket with a bead of acoustic/elastomeric sealant on each side.

expanding foam is hard to get right in a space that small, out of a can anyways.

Yep, I saw that, but he also has older videos with just a gasket, or some with a gasket and them some paint on rubber. All over the place. I think I may just lay some caulk between the blue foam sill seal, then wood right on it.

Will probably use a ramset as well, put 2-3 nails in each one as the lack of a wall on top pushing down can't help.

 

[Mattlt]

Interesting. When my bookshelf building was built, the bottom girt does not touch the floor. 2" foam on the floor, with a piece of foam turned on its side to act as a thermal barrier under the bottom girt along the outside wall.

I then fastened plywood to the walls, starting in the center of the bottom girt. I suppose I should fill that bottom cavity with insulation and attach a baseboard, but I haven't gotten around to that yet.

 

[bradpac]

Not sure what gasket is best, but on your outside panels make sure they have a tight fitting base angle at the bottom of them and ideally have it hang below the top of the foundation. Use whatever sealant or gasket to seal that angle to your concrete and bottom shelf.