Just as I was planning the rainscreen layer for the siding, Repurposed Materials had an auction to move some of their excess inventory. Among the treasures being sold were several rolls of Waterway rainscreen. The rolls are 35′ long and 58″ wide and consist of a woven acrylic polymer and a fabric membrane on the outer side.
I bid on each set at one time or another during the auction week. First on three rolls, then a group of five and even the truckload of 14 rolls. But I won the five rolls. I think this amount will be almost perfect to fit the siding we have to replace.
I can use actual rainscreen membrane now instead of the furring strip method. I feel very fortunate to get this for just under $10 a roll. A roll of a similar product, Home Slicker, without the membrane sells for about $150 a roll. Their literature says the higher cost product (about $200) with the membrane is to help keep a stucco scratch coat from clogging the mesh.
I started on the first section of wall with a 3″ piece of fiberglass from the fiberglass corners I bought at an earlier Repurposed Materials auction. Then I put on a galvanized metal z flashing above that. The siding is supposed to be at least 2″ from the cement walk and 6″ from dirt. So the fiberglass strip protects the membrane and tape that are closest to the cement. On top of the z flashing is a layer of the rodent/insect proof steel wool. It was difficult to cut the roll in half and I think I will order the narrower rolls when this order is used up. I used about a 1 1/2″ strip at the top and the bottom.
There was no way to slip z flashing under the stucco header, so I used the z flashing upside down with a layer of the rodent material overlapping about 1/2″ and then the rainscreen was cut to go between the two edges of rodent screening. The flashing, xcluder rodent material and rainscreen were all put up with galvanized roofing nails.
The rainscreen membrane is disintegrating from being outside in the weather. I removed the worst area at the beginning of the opened roll. The membrane is not an essential part of the system anyway. It is water resistant but it seems it is just there to prevent the mesh from being clogged. The matting is easier to install than lathe and will proved the breathability that a rainscreen wall requires.