Joists drafty

[dormermike]

Hi

First post here but have read lots.

Was hanging a light pendant and I couldn't believe the draft (gale) that was coming out of the hole in the ceiling. Looking up in the eaves (its a dormer bungalow) the soffits open up directly (albeit at a 90 degree angle) to the joist space. What can I do about this - is it OK to block it off with wooden planks cut to size? or just stuff insulation into the space?

Thanks
Mike

[dormermike]

OK from doing a little more research, and for the benefit of anyone reading this, I have discovered that soffit dams seem to be required. My roof construction does not have these, seemingly.

My eaves are boarded on top of the joists to approx one foot from the soffit, presumably for ventilation. The joist opening is "open" barring the small bit of insultation crammed into the opening, which in most cases doesn't block the joist opening sufficiently.

Its a big roof, and I have both sides to do.

If someone could give any tips on this i'd appreciate it please - presumably there are different materials etc that I could consider for the dam construction. Also would be good to know if I need to install the dam within the opening, or outside it? Outside would be easier to save cutting hundreds of short lengths to fit inside the gaps between the joists, I could jjust have long lengths of it presumably?

Thanks