I had a flat roof redone two years ago. it has leaked so got someone in to look. They tell me the old roof has been left underneath. I contacted the roofer who did the job. He tells me he used torch-on felt system to all areas and details comprising of:
3mm high performance underlay.
High performance mineral cap sheet to the area and edge details.
Apparently he tells me it is overlay - My question is should torch on felt be put onto chippings on the old roof? and only stuck down around edge.
I had no idea he had left the old roof on.
Can anyone here advise. please.