When I pointed out to the manufacturer that their web site said that their domes are guaranteed weatherproof, they were very concerned that mine had let the rain in. They explained that they had never heard of this having happened before, but promised to order some self-adhesive foam strip to stick under the shutter. Three weeks later this has still not arrived so I cannot really comment on how well it might work.
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I illustrate the solution here, where the foam strip is indicated in red. I do not know how wide the tape will be, but they told me that the thickness is 7 mm, about half the width of the gap. I think they may intend that I stick it to the underside of the shutter as well. My main fear about this solution is manoeuvring self-adhesive tape into place on the dome (which will have to be done with the shutter closed). Also in my case, I would have to do it standing on a sloping roof rather a long way above the ground. It may also be difficult to stick it to the underside of the shutter (depending on how wide it is) because of the attachment for the chord that closes the shutter. There would still (in theory) be a 1 mm gap between the strips but I seriously doubt water would be blown through it. |
After a little more prompting from me, this tape finally arrived. As you can see, it is two strips of tubular rubber foam which is very soft and has two strips of adhesive. The instructions were to put one piece across the underside of the shutter and a second piece across the dome itself about 50mm in from the edge. This was difficult with the shutter in place but made easier by the fact that there were two strips of adhesive. It meant that if I loosened only one strip, I could keep the sticky bit away from the surface whilst sliding the tape on the covered half into position. After it was stuck in position with the first section, the backing could be pulled off the second strip and the tape finally fixed down.
With the shutter fully open, I spaced the piece on the shutter slightly back from the edge by putting a piece of poster hanger across the edge and using its edge to locate the strip as I moved it into position whilst removing the backing strip. This means that the tape only partly goes over the bolt where the chord attaches (at least I think that is true). It was also necessary to ensure that the tape went under the chord.
The piece attached to the dome was most easily positioned from the inside. With the shutter about half open the chords could be slack and moved out of the way whilst the tape was inserted under them and around the pulley. It might have been easier if I had removed the pulley but I preferred to avoid any more dismantling than was necessary. As before, removing only one strip of backing at first made it a little easier to slide the tape into position. I judged the spacing from the edge by feel but it has not gone on very straight. It is difficult to tell if the strips touch all along their length or not. Time will tell how effectively this has sealed the gap. At the time of writing there has not been much wind or rain.
The closing chord of course passes over the rubber strip. It remains to be seen how well if resists the effects of the tight chord being pulled over it.
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