DIY Doctor UK DIY Forums

We are having a window and front door installed in to space where garage door was. Our builder is using a 4" by 2" frame to make the structure to support this. The frame is going to be insulated, boarded, felted and meshed. Our concern is that the 4 by 2 frame is being fixed directly into the base of garage ( ground level ). Should there be a layer or two of brick work first as surely rain could get underneath the wood even if rendered to ground level ? Rain always came under are old garage door. Internally the garage floor will have layer of membrane, celotex, another layer of membrane then chip board on top of that. Would appreciate any advice.

If you are converting the garage into living accomodation you need to apply for building regulations as you must comply with the insulation and fire regulations. Failure to do this is a legal matter and you can be asked to remove everything you have done. You may also need planning permission to alter the garage door. You should, under all circumstances, have a damp froof membrane 150mm above ground level.

Thanks for relpying so quickly. We have all the planning and building consents. It is interesting that you say the membrane has to be 150mm above ground level as the building inspector is OK for the first membrane to be laid directly on to the garage floor, which does not appear to be above ground level, hence our concern with the 4 by 2 timber frame going straight into the ground and water getting through underneath.