Cold Attic but why?

jasgrif11

Hi All,

I recently completed my new build and I put 100mm aeroboard platimum in my wall. I put 150mm of fiberglass inbetween my ceiling joists and another 150mm over the ceiling joints. I didn't put any insulation between the "ridge rafters". My problem is this my master bedroom has a double height ceiling and the room can be chilly even with the heating on (not cold but just not as hot as other rooms).
My attic is also cold but I put this down to the fact that its ventilated? Should I increase my attic insulation or add a product like Aerodorm to the space between my ridge rafters?

Thanks
J

ART6

jasgrif11 wrote: »

Hi All,

I recently completed my new build and I put 100mm aeroboard platimum in my wall. I put 150mm of fiberglass inbetween my ceiling joists and another 150mm over the ceiling joints. I didn't put any insulation between the "ridge rafters". My problem is this my master bedroom has a double height ceiling and the room can be chilly even with the heating on (not cold but just not as hot as other rooms).
My attic is also cold but I put this down to the fact that its ventilated? Should I increase my attic insulation or add a product like Aerodorm to the space between my ridge rafters?

Thanks
J

A room with a double height ceiling is bound to be colder than one with a normal height given the same heat input. Warm air rises, so a lot of the heat will be collecting under the ceiling. In industrial buildings that is overcome by fitting fans in ducts under the roof to blow the warm air back down to floor level, but I would doubt you'd want that in your bedroom!

Given the insulation you have installed on your ceiling rafters, why are you surprised that the attic is cold? If I were you I'd worry if it wasn't:D

RKQ

Art6 is right. Your unsulated attic should be just slightly warmer that outside!

Heat will rise especially in high ceilings. Some people install those ceiling fans with a light fitting. Fans rotate one way to push heat down in winter and the opposite way in summer to pull cool air in and up!

Insulation will slow heat loss it can't prevent it! Air moves all the time.
Airtightness and cutting draughts may help.

ART6

Just one other thought that occurs to me -- If your attic floor is well insulated, make sure that any copper pipes in it are also well insulated or they could conceivably freeze in the sort of cold snaps we have had recently. Been known to happen!

jasgrif11

Thanks Guys. A ceiling fan is out of the question though. I should have said that the room has 2 triple glazed windows and also 2 velux windows in the ceiling so there would be heat loss there anyway.

I increased the UFH in that room and it appears a lot better. I was just wondering if I have sufficiently insulated the ceiling space?

ART6

jasgrif11 wrote: »

Thanks Guys. A ceiling fan is out of the question though. I should have said that the room has 2 triple glazed windows and also 2 velux windows in the ceiling so there would be heat loss there anyway.

I increased the UFH in that room and it appears a lot better. I was just wondering if I have sufficiently insulated the ceiling space?

If you have two layers of 150 mm insulation I would think you have it about as good as it's going to get. In any case, you say that your attic is very cold. That's an indication that your insulation is good.