Ask a tradesman


Single storey extension roof

Hi what size timber is adequate for a single storey lean too roof? Extension comes away from house 2.8m.

2 Answers from MyBuilder Extension Builders

Best Answer

its probably going to have a low pitch, so use 8x2 treated


Answered 16th Oct 2017


Usually 4"x2" rafters at 40cm centres will be sufficient IF you have a ceiling below, however, 6"x2" is recommend if that is going to be your ceiling as well as a minimum insulation of 100mm thick is required in between the rafters. This then will allow another 50mm air gap for prevention of any condensation.


Answered 17th Oct 2017

Post your job to find high quality tradesmen and get free quotes

Can’t find an answer? Ask a new question

Question Categories