Sealing the "top of exterior walls"?

[Glenn]

IECC Table R402.4.1.1 or IRC Table N1102.4.1.1

"The junction of the top plate and the top of exterior walls shall be sealed"

What junction do you believe this is referring to? What part of the "top plate" seals to what part of the "top of exterior walls"?

 

[mtlogcabin]

I would guess the drywall and exterior sheathing.

 

[ICE]

No clue

 

[steveray]

I would think sheathing and plate. I know they guys around here started using a sealer at the interior of the top plate at the drywall to meet the air leakage stuff....So maybe the outside now too to reduce even more?

 

[JBI]

Where walls meet floors and ceilings need to be air sealed, same as around fenestration products.
Poorly worded as I believe the top plate IS the top of the exterior wall... probably should read top plate to ceiling and bottom plate to floor.

 

[mtlogcabin]

So how many enforce this section. We don't and we never have had a house fail the blower door test.

 

[Glenn]

Referencing my attached photo: I have seen a few builders do this with a few different products (seal the drywall to the top plate, but at every single wall, even interior). They were all building above energy code homes, so I assumed it was part of that program and their own stringent performance expectations. I thought maybe this is what the code above is referring too, but the wording is so horrible, that I'm not sure.

 

[steveray]

If it passs the blower door I am good....

 

[Elior Rosenkrantz]

I do blower door testing and when they fail I perform an energy audit. Basically depressurize the home and walk around with a thermal imager to detect the air leakage.

I can tell you first hand the most leakage come from where the outside walls meet the ceiling is always the leakiest part of the home. The insulation companies don't seem to be stuffing enough insulation into those areas. They are harder to reach and of course more time consuming.

Ori Rosenkrantz
LocalEnergyAudits.com
BlowerDoorTester.com

 

[mark handler]

IECC Table R402.4.1.1 or IRC Table N1102.4.1.1

"The junction of the top plate and the top of exterior walls shall be sealed"

What junction do you believe this is referring to? What part of the "top plate" seals to what part of the "top of exterior walls"?

 

[Pcinspector1]

I'm seeing caulking at the sole plate/floor connection and the inside corner of the wall. Sometimes I see a bead of caulking between the double top plates, depends on the insulation installer. However we do not do an insulation inspection, there are limitations on how many inspections we can perform on a house. Insulation and drywall are spot inspections only and no blower door test is required. Also the contractors here are using house wraps and zip panels in our area.