Solutions for rain screen strapping “sucking in” rigid foam?
Kraphtymac
| Posted in Green Building Techniques on
During installation of 1X4 strapping (fir) over rigid foam (EPS) with Headlok screws, my builder has been remarking about the Headlok screws tendency to “suck in” and compress the foam.
Anybody have creative solutions for this?
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Search and download construction details
Replies
Thomas,
As long as the furring strips end up co-planar, a slight amount of compression is not a problem.
There are two possible approaches:
1. Learn to stop tightening the screws before compression occurs.
2. Compress the foam under each furring strip equally.
Some builders have an instinctive feel for how tight to go. Others don't have that instinct. If your builder is having trouble keeping everything co-planar, he or she should keep a 4-foot level handy. Every now and then, check to make sure that the furring strips are co-planar. If an area got sucked in too far, back off the screws. If one area creates a hump, tighten the screws that will suck in the hump.
It may be possible to control this by setting the clutch on the driver for only a little more torque than is needed o get the screw in all the way.
Sometimes you have to use a string too. You can ease them Bach out to reduce the tightness too. Sometimes you have to use shims here and there. Walls without foam are never perfect, either.