advice re: re-roofing garage please

[diy_fun_uk]

Hi

I have a single car garage built in the 80's. The roof structure comprises wooden joists with concrete/asbestos corrugated sheets:



The sheets are now starting to fail i.e. although they still look sound they are no longer water-proof, heavy rain now results in a wet garage floor and when I look up the underside of the sheets is wet through. The pics above were taken when everything was nice and dry!

So, time to replace.

I'm going to seek quotes from local builders/roofers to remove and dispose of existing sheets and replace with new roof. I'm hoping the existing joists can be left in place. On looking around, my neighbours have mainly gone for felted roofs whereas I was thinking about metal or bitumen roofing sheets e.g. something like this or this.

Can you advise, working on the following options, which one would you recommend? The garage itself is old and an all singing/dancing 100 year warranty covering isn't required.

option 1: boards and felt.
option 2: metal sheets.
option 3: bitumen sheets.

 

[^woody^]

Steel and bitumen sheets have a very short life, and to be avoided if noise and condensation might be a problem.

Similar profiled cement sheets are a much better option and will be much more durable than the others you mention.

 

[oldbutnotdead]

You can get GRP with the same profile as many patterns of cement sheet, not sure how well overcladding would work if the cement sheets are held down with those big button nails but might be worth a look.

 

[catlad]

Simplest solution is to replace with the modern version of what you have now.

 

[diy_fun_uk]

Hi All

thanks for replies and advice. I think I'll avoid metal sheets due to reasons mentioned e.g. possible condensation, noise. I'm now looking at the fibre cement as mentioned by you, maybe something like this:

http://www.steelroofsheets.co.uk/products/fibre-cement-price-list-and-order-form/

I'm a competent DIY'er and, especially if I'm essentially replacing like for like, you've no idea how much I'd like to do this myself. However work does take up much of my time and, including the fact the existing sheets are asbestos, do you think I should save myself the hassle and get a roofer to complete the work?

 

[catlad]

If you go to your local tip tell them that you want to bring in some old asbestos roofing sheets and they will tell you the procedure, in my area they will give you some thick visqueen sheets and tell you to double wrap it.