Eleven years ago, I built a greenhouse with a 2' high pony wall. That wall is "L"-shaped, 36 feet long on one side and 18' on the other. The wall was framed with 2X4 rough cedar. On the inside is poly (polyethylene, not urethane) (visqueen, Keith) and 1/2" plywood. Fiberglass insulation between the studs, and 1/2" plywood sheathing on the outside. The sheathing is (was) covered with 2" expanded (white bead) Styrofoam, and with cement board (i.e. the modern equivalent to asbestos board). The top 12" had vertical cedar siding and the bottom was dirt, as there is a 32" wide irrigated raised garden bed on the
*outside*. (Inside greenhouse beds are plywood boxes, so dirt does not touch the wall there.)So, I recently had all the dirt removed in the raised bed so I could check out the condition of the wall. Removed the siding and the Styrofoam (the cement board had practically disintegrated). The plywood sheathing had considerable rot. The wall framing is in pretty good shape, the sills have no rot that I can detect, and only three of the studs have rot on them. The interior plywood sheathing looks like it's got rot in quite a few places, i.e. it looks black behind the polythene. But I'll fix that once I've solved the problem I'm asking for your ideas on; namely:
What do I do now? Bear in mind that one side (inside greenhouse) is hot and damp, and the other side is cool and wet (dirt in raised bed). Things I have thought of:
Use galvanized sheet metal as sheathing (this would isolate the wall from the dirt). Pour concrete between the studs (hard to do & I would lose the insulation value which is important as we start using the greenhouse in March, which is still winter here in the Yukon) Remove the raised bed (Not acceptable to the LOML - she'd rather dig out the bed every ten years)
What would you do? Any brilliant ideas?
Luigi Replace "no" with "yk" twice in reply address for real email address