How to Insulated plasterboard

[DIYinsulation]

Hi

I recently bought a house with a loft conversion, however the loft seems to always be cold. So i was thinking i should insulate it.

I'm thinking the the most effective way would be to buy plastered insulation board and put it on the ceiling, but all the walls are already plastered/painted, would this affect the fitting of the insulation, also can i paint directly over the plastered insulation (after filling the gaps).

I was thinking of getting thermaline super (60mm), anyone used this before?


Thanks

 

[skhudy]

Is it an "official" loft conversion? or a posh loft. You don't want to be adding extra weight up there to the original rafters. I ask because if done correctly it should already be well insulated

 

[DIYinsulation]

Hi

Thanks for replying

I'm not sure what you mean by posh, but it's got smoke alarms, and fire exits as required by regs. its also got a couple of beams running across each side. The roof thickness is only around 18cm from tile to inside, and even if it does have insulation it'll need more i think.

 

[skhudy]

Hi
I'm not sure what you mean by posh, but it's got smoke alarms, and fire exits as required by regs. its also got a couple of beams running across each side. The roof thickness is only around 18cm from tile to inside, and even if it does have insulation it'll need more i think.

Posh loft is one done without planning permission. When you say beams running on each side it sounds like you mean the purlins (part of the original roof structure). Usually there is some kind of V shaped support in the middle of the Purlins resting on a load bearing wall in the middle of the house (I guess this is not there any more).
Having smoke alarms and a fire exit is a fraction of the regs.
I don't think it is an official loft conversion, the problem is if not, and you start adding extra weight, you can potentially cause a problem to your roof (which weighs several tons) especiallys if the structure has been altered. When you say the thickness is 18cm, these sound like the rafters which are holding up the weight of the roof.
If so I wouldn't add anything.. maybe get someone in to advise it is structurally sound...

 

[DIYinsulation]

Oh, that's not what i wanted to hear haha
I've got to get the roofer in anyway (for a problem on a different roof), so ill see what he has to say.

Thanks for your help

 

[DIYinsulation]

Although, i found a calculator that measures if the roof would be able to handle the extra load, http://easy-pv.co.uk/structural.php

in my situation, the insulation weighs 7kg per meter squared, over an area of 13 meters squared that would be 91kg. Im not sure of the weight of roof covering, i just put 15. and it says its within limits.

I'll still get the roofer's opinion though.

 

[skhudy]

The roof has got the extra weight of the flooring, plaster boarding, carpets, furniture? likely to have been structurally altered - missing collar Ties? / Purlin Supports? staircase put in so the ceiling joists altered.. the weight distribution has all changed.. You need a structural engineer / architect not a online calculator!!

 

[DIYinsulation]

oh, well there were no collar ties or purlin supports before the conversion, and i would have thought it would have been the floor that supports all of that weight.

 

[NickB_99]

I recently bought a house with a loft conversion

If it's recently bought, what did the survey say about the loft conversion?
Hopefully your solicitor would go through it also and make sure any building control sign off is correct, if it was claimed as a proper loft conversion.

I don't necessarily think asking your roofer would give you a definitive answer either.

 

[Alastairreid]

A roofer can install coverings to the roof structure! not design and load capacities.