Dome build. The perils of rubber skirts and flashing.

*

Wednesday: A dry and mostly sunny day. Completed cutting and fitting most of the dome's 90mm [3.5"] wide skirt flashing. Only the observation slit and the two shorter lengths to do by lunch time.

I'm trapping the upstand under the edge of the lower panels of the dome. A couple of small screws just above the flashing ensure a tight hold. I haven't tried to drill through the flashing for a permanent fix yet.

One support roller is slightly outboard of the rest of the circle and is rubbing on the flashing as it passes. I shall have to move the roller inboard slightly. I drove off to a fish pond specialist to buy a strip of heavy rubber pond liner but found they were closed for the whole month. They had stacks of pre-cut pond liner on the ground just inside the gate. Grr!

Oh well. I have ordered a meter of the 1.2mm heavy EPDM in 7m width from another dealer online. Free postage. If I cut it into strips I shall have more than enough to have two complete skirts. One hanging from the flashing outside and the other inside the base ring. That should keep the drafts and the rain out! Though I'll have to find a way to protect the rubber form the steering wheels. A metal strip?

My hope is that the EPDM it will be floppy and heavy enough to hang straight and vertical. Yet be able to move gently aside if there is any obstruction. I have some 1/2mm thick, plastic pond liner but it is very stiff. The folds are still in it from when it was bought. It would never straighten out no matter how long it hung there. Though I could have tried a heat gun I suppose.

I had to remove a 2"x8" from the octagon top ring without being able to get at the screws with the drill. So I used a ratchet and Torx driver and then half a tap wrench with a Torx bit for the last inch.

Finally I was able to remove the support wheel and frame. Then move the four holes inwards by 20mm. Then I had to drill a new hole for the steering roller and hold down disk in their shelf bracket support. Job done as dusk fell and the bats came out. It's been a long day but well worth taking advantage of the dry weather and sunshine. It's a shame I could not take advantage of a dry day to seal the dome.

The image shows the inside stains from repeated cloudbursts. The big mounting is multiple wrapped under the black gardening bag. With the stepladder "scaffolding" towering over the top.

Thursday. Moved another support roller inwards. It was brushing the metal flashings. Probably due to eccentricities as the dome rotates. Moved the steering wheel outwards on the bracket to match the change. Removed all the flashings and trim routed the plywood on the bottom of the dome to take out variations in overlap.

Still thinking about the best method to clean up the flashing joints at the drip nose. Because the profile is double, just there, and folded at an angle, it doesn't take kindly to small cuts with the tin snips. The flashings certainly reduced rain infall through the midriff gap far better than I had expected. I trimmed off the bottom of the slit ribs to make room for a length of flashing there. Last, I chopped off the accessible corners of the 2"x8" octagon top ring to stop the rubber skirt from dragging. The rubber should be here tomorrow.

Friday: Returned the two support rollers to their original positions. Moving them yesterday resulted in an offset dome relative to the octagon. The skirt would be dragging over the octagon's corners.

The rubber has arrived. Incredibly heavy it was too. The suppliers were quite generous with the measurements but had cut the strip on the diagonal! I cut along one of the manufacturer's moulded lines and ended up 8" from their cut edge! It just scraped in at 1m wide to the wavy opposite edge.

There was some damage too. With a couple of large, permanent looking dings. Not penetrating, but I'll have to avoid it on cosmetic grounds. It wouldn't matter for a pond. Because it would be under the surface and pressed flat by the water pressure. Still not what you would expect though at about £8 per squ.m.

Click on any image for an enlargement.

*