First rain: leak testing

Yesterday it rained most of the day, varying between light drizzle and fairly steady rain. I spent some time inside the POD, dome closed, looking for leaks.

The structure itself seems completely leak-free. No noticeable water running or drips anywhere around the boundary between the two dome halves — the gaskets are working.

Some water intruded under the wall by following the “valleys” where deck boards joined. I had caulked around the entire dome, both inside and out, but these deep inter-plank valleys still allowed a little water through. It didn’t go anywhere — it stayed in the inter-plank valleys, came in a few centimetres, then disappeared (presumably either soaking into the wood or dropping through the crack). In any case, I marked the spots, and when the wood next dries out I’ll add extra caulking at those points on both sides.

Update: one leak and some caulking problems appeared overnight.

Checking again this morning, I note two problems that will need some attention:

1. The caulking I put on the exterior side between the dome and the deck was only a few hours old when the rain started. It needed more curing time than that, because the rain seems to have washed quite a bit of it away — there are gaps below the wall where I know I had a smooth bead of caulking. I’ll have to re-do the exterior caulking some time when the forecast says it’ll have a day or more to cure before rain. I see now, checking the users’ group forum, that there seems to be a known problem with this hi-tech caulking that goes on white then turns clear that I used on the exterior — it needs a lot of curing time before it can stand getting wet. The normal clear silicon I used in the initial assembly has survived fine (although it did have several days of curing, so is not really a fair comparison.) I’m thinking of stripping the colour-changing stuff out and going with traditional clear silicon, whose properties I know, and that I know works well.
2. Found a leak inside that hadn’t shown yesterday — there is a small puddle inside the observatory where water had dripped off the inside of the dome. The leak appears to be in the seam where the two halves of the primary dome are joined together (not, as I would have expected, the joint between the primary and secondary domes). I think I can see a tiny break in the caulking along this seam on the outside of the dome. Again, when I get my hands on a good long stretch of rain-free warm weather, I’ll touch up some caulking. Meanwhile, I’ll move things out of that spot so they don’t get wet, and leave that area clear until further rain days confirm I’ve found & fixed the leak.

By the way, note to self:

All this testing is without having installed the POD cover yet. No doubt it will completely eliminate any leaking, but I want to get leak-free without it, so it becomes additional protection, not mandatory protection.