Correct size holesaw for a bathroom extractor fan

daivid

I'm having an inline extractor fan fitted and will be doing the donkey work. Does someone know the correct holesaw size for the vent covers? One to go in the bathroom and one under the eves. The ducting is 100mm and the choices of holesaw blade that make sense are 102mm and 114mm. On paper 102mm would be very tight but am I right in thinking holesaws tend to cut slightly wider holes than their given diameter? Also the vents covers have a tube that push-fits inside the ducting so presumably is slightly less than 100mm (though that could be a nominal 100mm?). The electrician will be bringing all the parts on the day he does all the wiring work so I don't have the cover to measure unfortunately.

TELLIT01

Phone the electrician and ask him.  There will be details with the kit he is going to install.

fenwick458

I use a 110mm, any bigger and it's hard to fix the grilles to the ceiling, any smaller it's very hard to fix the ducting to the grill and then get it in the hole.