easy, done thousands of roofs with the stuff,
buy a can of what ever sort of chemical you are going to use, lets say either the stuff from tool station or cupronol, i take it you do not need a gaurente, if so you need to call a company
the main thig to do is to clear all the dust and cob webs off the timbers as we want to treat the timber not the dust. we used to brush down all the rafters first, then we would put the chemical into a garden pump up sprayer and then spary every thing so its well covered, then if we had isulation we would then start at one end rolling the fibre glass back bruch the ceilig joists off then spray them and then roll it back and then roll the over way and then brush and spray them.
if you have a open ceiling just dust ever thing off then spray it all.
the usual clevate applies about wearing a great dust mask as we dont want to kill use off and put all the gear outside, leave it open for the day to vent every thing off then put it all back at night and it would not effect the bee equipment as it wont be covered in chemicals
most wood worm treatments work by poisioning the woods surface and they dont penitrate to far in. the way it works is that as part of the wood worms life cycle it turns from a wood worm to a bug and in doing so it burrows its way all most to the surface digs a little cavitiy and pupates it then bites its way out of the timer to then fly off to start again, so going in and coming out it nibbles of toxic wood.
if i remember rightly there was some form of herbal treatment that was based on Boron but it was a while since i sprayed a ceiling out. even so there are better chemicals to use than white spirt based suff we used to used water based as it was less smelly and cheaper , we used to buy a litre of chemical and add it to 25 litres of water
you can buy a chemical that is just wood worm killer or what we used to call dual, which used to do rot as well as worms.
