I want to replace my aluminum siding with vnyl siding. The contractor suggests that he remove the aluminum siding and add foam sheeting, (I am not sure of the depth) before installing the vinyl. Is it safe to have foam underneath the vinly and if so what depth and should there be another vapor barrier?
Answer:
The old siding should certainly come off and underneath the new, you might consider 1.5" of rigid fibre insulation rather than foam because of the cost. More than 1.5" of rigid foam becomes a vapour barrier on the wrong side of insulation and you don't want that. Fibre, on the other hand, can be applied in any thickness.
