Colorbond roof laid with overlap facing into the weather

Colorbond roof .My roofing sheets have been laid the wrong way ( overlap facing into the prevailing weather) on my new home. I am going to try to get builder to relay roof correctly as i am nearly at handover stage and am still refusing handover until I try too get this and a couple of other issues sorted out.The SS told me because it is in a catergory 2 wind zone it doesnt really matter what way the sheets are laid is this true we live on the-(Adelaide Plains close to Coast) Has this happened to anyone else and has anyone been able to get roof relaid the correct way or is the correct way only a recomendation ?

This sounds familiar Have you done a search of the forum?

Yes i have posted similiar questions before but trying to find someone that has had this problem and if anyone has been successful in getting their roof relaid the correct way.

I came across the following document that might help your cause, unfortunately it's dated 2007 but the standard is probably still current.

Look under laying procedure for the relevant information.

http://www.colorbond.com/files/dmfile/T ... er2007.pdf

Having been involved in the roofing industry for a few years in a past career I can tell you that what ever the 'technical requirements' of laying the overlap are, in practise noone really does it. I don't believe it is important as colorbond sheets are designed so that the overlap has an 'anti-wicking' function so that water doesn't penetrate due to surface tension. The laps are closed when installed so you can't get wind blowing in like you can at a ridge where the sheet pans need to be bent up to prevent this. You are more likely to get leaks where you have a sheet overlap on the end rather than the sheet overlap on the side which is why sheets should be in full lengths as with end overlaps the sheets are flush together and water can 'wick' up between them with surface tension. I have never seen or heard of water blowing in under the side laps of sheets that are laid and screwed off properly and I have supervised the installation of probably a couple of hundred roofs and been involved in the building industry for 15 years.

Also you can't just take the sheets off and 'relay' them - they would have to be replaced. My advice would be to leave the sheets as they are and then only complain if you actually get leaks which I think is highly unlikely.

Thanks yetti, I appreciate that more than you think! I have had a bit of bad luck in my house build (see 'Issys Hamilton Alfresco' in building a new house). I wanted to find out if the roof thing was against the building code or if it was just a "recommendation" before I added it to my thread. Cheers again, Issy

PS- Thanks Arcadia for your input aswell