I found a great buy at the Habitat for Humanity Restore: 900 square feet of exterior drainage mat for $100. This amount sells for about a thousand dollars retail.
When installing siding, especially in wetter climates, it’s a good idea place spacers strips between it and the exterior sheathing on the walls. In the case of the beach house, this will create an air space to allow the cedar shingles to dry out much more quickly. If siding stays wet over longer periods of time, it can cause rot, warping and paint failure – and I really want to avoid all of that.
When I did the front of the garage, I used 1/8″ plastic strapping to create the air gap.
The straps are spaced out so they keep the shingles off the felt paper, and the nails go through them to make a solid connection. The 1/4″ spaces between the shingles lets air flow up into the voids to allow for drying. Overall, I think this will work well over time.
While I’m happy with the result on the front of the garage, I want to improve things before I start work on the house. I decided that on the ocean-facing sides I wanted to go with at least 1/4″ gap to ensure enough air space, since the wind regularly blows salt spray and rain there. Also, the plastic strapping gets unwieldy and wants to bend, causing bubbles that I have to staple down. I wanted to go with something else, like wood or corrugated plastic battens, which I’ve been investigating. The perfect choice is drainage mat, but it’s really expensive.
I should have expected to find what I wanted for a really low price… I’ve found shingles, stainless steel fasteners, and flashing material all for a fraction of the normal cost. I now have 8K worth of material for less than $1,500.
To the right is a strip I cut and placed between a couple of scraps of wood. The screw is in fairly tight, and the mat holds it’s shape. It’s the equivalent of a 1/4″ thick batten that fully allows air, and doesn’t have any moisture spots that solid ones would have. It’s perfect. If I want ease of installation, I can put large sections of it on the wall – or if I want to save material, I can use 2 1/2″ wide strips. Both seem to hold their shape equally well. If I make the strips, I can do the entire house and the rest of the garage with what I bought, plus some to spare.
I’ve read that nailing through the mesh can be tricky, because it tends to bounce a bit. I’ll work that out before I get started on some test pieces.
Update: I found another 1000 sq ft of this for $100 a few weeks later. So I won’t be cutting any strips. I can just put up full sheets of it. And if I find any more rolls of it at this price, I’ll buy it and store it.