AirTightness without Sprayfoam
homedesign
| Posted in Energy, Heating & Insulation on
I am searching for Airtightness strategies that are achieving 1.5 ACH50 or better.
I am also trying to avoid sprayfoam for a variety of reasons.
If you are achieving good airtightness without spray foam please comment here
or join this discussion at the JLC Building Science Forum
http://forums.jlconline.com/forums/showthread.php?t=49172
Thank You,
John Brooks
Replies
http://www.cellulose.org/userdocs/TechnicalSpecifications/ConsumerUpdate01-InsulationEffectiveness.pdf
Worth a look.
Joe H
Only if ya shellac it afterwards.Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations
"If Brains was lard, you couldn't grease much of a pan"Jed Clampitt
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Why didn't I think of that?
Shellac, the Universal Sauce...............
Joe H
When i knew less than i know now... which still ain't alot... I stripped down a frame building to the studs and replaced the damaged plates... this was to be our offices so i wanted it sealed up tight... and I had a very small budget...
I sheathed it with a 3/4 foil faced foamboard... taped the seams... and glued it to the studs and plates... I din't spend a ton of money... but i spent a ton of time sealing everything... liquid nails and caulk... before the standard for the time fiberglass batts went in... i spnt a ton of time with those also...... it is a small 1600sf building... with vaulted ceilings.... even with commercial gas & electric rates... the ac/heat bill has always been less than $100... thats with water sewer... garbage collection...
so guess i did good or got a faulty meter
P
I've seen people get say around 0.10 ACH (natural) not sure what that converts to at 50 Pa with standard framing and fiberglass batts. They did it up in the NW 15-20 years ago. These are tested values. Their key was lots of caulk and attention to details where air leakage can happen and avoiding many of the things that exacerbate leakage (e.g. like the conventional recessed can lights in the exterior envelope). But they did do some recessed cans ... they just gave them some extra attention).
One strategy was drywall the thermal envelope before interior partitions are put up. Some of these guys caulked the bottom edge of the drywall. Lots of attention to the framing around the windows, too. It tends to be labor intensive. Given that, foam systems cost may look a lot better.
Clew,
0.1 ACH natural may translate to about 2 ACH50 +/-
I think building the Exterior Walls first is a damn good strategy.
Yes ... alternatives to foam are labor intensive and require new methodology...but once it has been achieved...then the doors are open for Uber-Insulation at an affordable cost.
Edited 9/10/2009 11:25 am by homedesign