aAsk a Tradesman

My attic has been converted into two bedrooms, I have a normal staircase leading up to it. I have 4 hatches around the side walls. Inside these hatches I have noticed,due to the wind and chills, that there is no insulation whatsoever on the underside of my roof tiles. What should I be using to insulte this and what are the legal requirements and regs. ie spacing for ventillation? Do i also need to board over whatever I use to insulate this area.Any help would be greatly appreciated as i have a roll of rockwool and was going to use this and hold it in with sheets of wood. Is this wrong?
i would like to add that the conversion was signed off and certificated but was done before myself and the previous owners lived there. It must be 15 years ago.
Once i've used kingspan or celotex does this then require boarding over or plasterboarding?

We have a bedroom above an unheated garage which leaves the floor cold, especially during the winter. The garage ceiling is plasterboard, and has had wood pulp insulation blown between the rafters. The bedroom floor is still cold, the overall temperature in the room is OK but about 3C cooler that elsewhere upstairs. Would putting thermal foil under the carpet and underlay be a cure? If not any ideas would be most welcome.

The ceilings are 2.56m high with the walls approx 3m wide

Thanks

whats the best way to celotex the internal garage(converting to bedroom)
build stud frame (3x2 treated) fix to floor and ceiling 25mm away from wall then celotex between and plasterboard

or............?

there is more then 1 way of doing this would just like to know which way other builders would do this.i have had 2 different building inspectors come out both with different ways to do it,so just though lets pick mybuilders brain

Our house has sloping ceilings to all the upstairs rooms. The horizontal ceiling accounts for around 40% of the total ceiling area and is insulated with glass fibre between the joists, accessed via the loft hatch.

However, this leaves a lot of uninsulated sloping ceilings with little room (around 5 inches) between the plasterboard and the roof tiles. The only access to these voids is by peering down at 45 degrees, once you are in the main loft space.

I must be losing a lot of heat via the sloping ceilings. How can I insulate these sloping spaces between the rafters whilst allowing for sufficient ventilation? I should mention that I'm not keen on insulating from inside the bedrooms. The ideal scenario is to find a way that allows me to insulate from above but still keeping ventilation to the roof space and avoiding condensation...

...and I don't want to do the work myself!

Thanks
Nick

What is cavity wall insulation and how will it be installed?