The old bitumen felt under the tiles on my 1930,s house is rotten .Is
it really necessary to replace it (off with the roof!), no great
amount of leaks virtually nothing, loads of ventilation, can see the
stars in places ...attic floor heavily insulated (~250mm rock-wool),
hatch sealed with strip...house fitted with CH .
There are no deliberate ventilation tiles near the apex nor any fitted
under the soffits (? at the bottom). what can be done in this
situation to sheet,ie prevent wasps/bees etc.gaining access?(one year
half a billion ladybirds..since gone and never returned?).Any ideas
please..