I have boarded the floor in the loft of my house (a 1920s built semi-detached) and have insulated between the rafters with polystyrene board to create a 'warm loft'.I've left a 50mm gap behind the board and covered it with a vapour barrier sheet. I use the loft for storage and access it infrequently but as there is only room for 4 inches of insulation under the flooring, I wanted to improve the overall insulation.
At each end of the loft there is a gap between the outer brick and the inner layer of brick on which the loft flooring rests. Presumably this gap runs around to the eaves and therefore allows cold air to flow into the loft. Also, the bricks in the gable end are fairly rough and I suspect air can flow through the gaps.
What is the best way to finish off the insulation job? Should I add studding to the gable ends, put polystyrene board between and cover it over? Or is there a better way to insulate them? Or can I just block off the gap at the bottom and not worry about the gable ends themselves?
There are two chimney breasts at one end, so boarding around them will be tricky unless I just board straight across and leave a large gap behind.
Thanks very much in advance for your advice.