Replace Corrugated Garage roof by overlaying

[Astra99]

Hi Everyone. My garage is at the end of a block of seven. The roofs are all corrugated cement board (not asbestos). The roof leaks, and no matter what I do I cannot get it watertight. I was considering overlaying my section of the roof with marine ply and then a "heavy" felt, re-using the existing lead flashing where the roof meets the wall. At the other side, where it extends to the next garage, I thought about dropping a fillet of ply (with felt) into the next "valley" and siliconing or using bitumen to act as a seal. Opinions, both negative and positive gratefully received.

 

[Elastomeric]

You will need to fit a timber in the trough of the deck to enable you to fix the deck. Stop your deck on the party wall, dress lead across 2 troughs of the adjacent, or Ubiflex if the lead may get stolen. Felt up and onto lead/Ubiflex.

 

[^woody^]

Will the roof supports take the extra loading?

 

[Astra99]

Thank you, Elastomeric for your input. It was how to finish off at the party wall that was causing me some head-scratching! Thanks also to Woody. One of the existing supports is rotten as a pear, so I was going to replace that before starting anything else. I might add a couple of extra joists just to be sure! It's a job I don't want to do again, ever!