suspended ceiling and insulation board

country home

Hi all,

Have hollow core on the house, and was looking into the suspended ceiling,

while there is as much space downstairs and upstairs, id like to initially keep heat were we will be spending the most time.

Putting in a suspended ceiling and just using regular plaster board seems a bit worrying, the heat will rise natually, and without insulation will firstly go in to the 5-6 inch gap then up to the hollow core.

I was thinking of putting a insulated board up, just like what ill be using on the external walls inside, 38/50mm board.

Question,

can this be done?
is there a weight issue?

cheers..

Bitten & Hisses

I'd recommend using standard plasterboard and filling the cavity between the plasterboard and slab with rockwool. This will provide you with both noise and thermal insulation.

Ordinary man

Its very uncommon for insulation to used between hollowcore and mf ceilings. If the ceiling was hung to timber then it would be used. As for using insulated slabs, it can/has been done by adding extra carrier and hangers but i would be concerned about the insulation shrinking in time and throwing off the levels of the ceiling.

country home

Ordinary man wrote: »

Its very uncommon for insulation to used between hollowcore and mf ceilings. If the ceiling was hung to timber then it would be used. As for using insulated slabs, it can/has been done by adding extra carrier and hangers but i would be concerned about the insulation shrinking in time and throwing off the levels of the ceiling.

could i fill the gab with rockwool as suggested in the previous post?

Ordinary man

There would be no problem with using it but i'd question whether the cost of the rockwool could be justified. I'd be more likely to recommend the foilback slabs.

mfceiling

Hi,

It's a question reallly of what you feel is the best idea.
I hung a ceiling this week in dun laoghaire where the builder wanted it boarded with 37.5mm insulated plasterboard as per the detail on the walls.
Yesterday i did one in carlow and the client was going to put rockwool in the cavity but was told that it could restrict airflow and could lead to mould.
Other builders have told me stories from - let the heat rise naturally and go into the hollowcore which will retain heat to putting foilback slabs on will reflect the heat back to the room below.
It's difficult to say what works best as even speaking to the lads who supply me with the metal, they all have differing opinions on what is the best option.
Maybe the Mods might have a better answer ie thermal properties, U-values etc.
Cheers, Gary

mfceiling

Sorry also meant to add that if i was installing an mf ceiling with insulated boards on it i would reduce the distance between the hangers from 1200mm to 800mm...it's more weight so a reduced span would help take the weight. Cheers.