Replacement for corrugated iron roof
Q. I inherited the old (very) stone-built croft house on the Isle of Skye in Scotland after my parents' deaths. I have done a lot of work on it when over in Scotland every summer, but the corrugated iron roof is a headache. The house would have been thatched, but I'd guess that in the early 1900's that was replaced with corrugated iron. The cottage is literally a stone's throw from the sea, so the salt air takes its toll. As a result, I have to re-tar the damn roof every couple of years, and I'm fed up doing it. The house is a listed building (because it's so old)so I can't change the roof without an official song and dance act or two.
My question is: Is there some material, resembling corrugated iron, which I could put on top of the existing roof - I'm thinking of corrugated aluminium coated with plastic? The existing rafters would not take much more weight, so the material would have to be light. Alternatively, is there something I can put on top of the tar/bituminous paint which presently covers the corrugated iron? (Last summer, by way of an experiment, I covered a few sheets with water-soluble silicone paint. It seems to be good, but I reckon I will know the truth when I get back this coming summer!)James Sligh
- Toronto, Ont.
A. How about using corrugated fiberglass and overcoating with a black silicone rubber caulking material? The rubber should keep the UV away from the fiberglass resin, and the assembly, although expensive, should go up easy and last quite some time.Bob Zonis
- Bohemia, NY
Thanks BOB Z. That's a good idea! I can see one catch, however; I've noticed that sheets of corrugated iron laid on top of similar sheets never quite fit exactly. Maybe I'd have to put battens on top of the existing corrugated iron before laying the fibre glass sheets(?)James Sleigh [returning]
- Toronto, Ontario.
A. This is a non issue. As far as I can tell onduline is a tar based pre colored sheet in the same profile as iron 850 mm cover. You could re-clad over existing; it's not so dare, suits the Scottish budget, and easy to handle and light. So there's my suggestion.
- Gisborne, Nzl
A. When I was in Norway I noticed that the roofs were turfed with grass and this kept the heat in and grew every year. I don't know much about the other things but only a suggestion. It is almost like thatching so you could argue that it was natural and it would have been burned out maybe in the first place. I have never been to sky, a disgrace I know but I feel it is beautiful. Every time I have set out to go I end up somewhere else, thats it I am definitely going next year. Good luck with your cottage.Maria Carroll
February 12, 2017
Silicone paint on the corrugated iron sheets was a total disaster. In fact, I took the paint company to court over their product. It acted as a paint remover and there was a hellish chemical reaction between the silicone and the zinc on the sheets... I have pretty well settled on replacing the existing sheets with factory-coated (painted both sides) sheets.
To Matt in NZ. I have used Onduline on sheds and it needs almost no maintenance. Sheep will nibble it if they can reach it! The Onduline I've used and seen however, has much wider corrugations that the galvanized iron sheets.
To Maria. If I turfed with grass I'd need new rafters etc. The weight is far greater than the corrugated sheeting. Hope you got to Skye OK... I'm Canada based, but generally managed home every summer.
- Isle of Skye, Scotland