DIY Attic Conversion Insulation Q

Myrddin

Hi guys, as the title states Im doing a simple attic conversion myself. I've laid floor insulation down, and fit the floor down over it. The next step is I want to plasterboard the rafters which make up the roof apex.

I was planning to insulate between these aswell, but somebody has told me not to - that they should be left clear to prevent dryrot and condensation. Im inclined to insulate them, but though Id ask for some advice.

Thanks for any input

Stratocaster

EnterNow wrote: »

Hi guys, as the title states Im doing a simple attic conversion myself. I've laid floor insulation down, and fit the floor down over it. The next step is I want to plasterboard the rafters which make up the roof apex.

I was planning to insulate between these aswell, but somebody has told me not to - that they should be left clear to prevent dryrot and condensation. Im inclined to insulate them, but though Id ask for some advice.

Thanks for any input

I am not an expert in this field but I have seen a good few attic conversions. As long as you don't completely fill up the space with a solid insulation you can insulate the space. Breathable insulation's like fiberglass and rockwoll can be used in some situations. Also if you can manage to bring up insulated plaster boards that could work. There is a foil roll available that has the same U value (heat loss resistance) as Kingspan. It comes in various grades of resistance and its expensive but ideal for your situation. You just tack it up before the plaster board. You will still maintain the full air gap throughout the rafters. Check your builders suppliers.

aujopimur

Insuating under the floor was not good idea as you will block any heat rising from the floors below
Insulating between the rafters is important, use kingspan rafterlock for this as it will allow ventilation to the roof

Myrddin

Thanks for the rples guys. Ill check my local providers for the said supplies. I actually laid the floor a good few years ago, and at the time had no intention of converting the attic, so therefore insulation the floor was more so for the benefit of the house. Its only recently Ive decided to do a complete conversion, and lifting all that tongue & groove to get at the insulation is NOT an option

So its Kingspan or its foil roll alternative Ive to ask for? Any idead as to a rough guide price?

Joey the lips

EnterNow wrote: »

Thanks for the rples guys. Ill check my local providers for the said supplies. I actually laid the floor a good few years ago, and at the time had no intention of converting the attic, so therefore insulation the floor was more so for the benefit of the house. Its only recently Ive decided to do a complete conversion, and lifting all that tongue & groove to get at the insulation is NOT an option

So its Kingspan or its foil roll alternative Ive to ask for? Any idead as to a rough guide price?

Personally speaking I never thought it a bad idea to insulate the floor even in an atttic conversion. Reasons being is that it might mean you need a biger attic rad but it will prenet all the heat loss from the rooms below.

TBH i think that as a standard all houses should be insulated in each floor confining the heat to each room.

On the insulatuion there is a gap that is suppose to be left. I am not to sure what it is,. Perhaps if you ask in construction and planning above home and garden. i am sure most insulation suppliers will tell you anyway.

Without offending. I am sure you left the insulation out under the attic tank.... It is no harm in wrapping the tank in insulation either, It help keep the water temperature higher saving on energy used to heat it with a pumped elestric shower,

irelandhouse

a good solution is to put a pitch roof solution
xtratherm is rafterloc, quinn insulation is pitchloc and kingspan is thermapitch

the are all pretty much the same, u values negligible

put this into the rafters, leaving a small gap, about 1 inch either side.
then put an insulated slab over this, it will be 38mm overall, 25mm insulation and 12.5 plasterboard.

this wil give you a good result and stop any sort of cold bridging through the actual rafter timber themselves.

where people make mistakes are in the crawl spaces, left where you are putting in the partition, use the insulated slabs and put a fibre glass in the partition bit.

do not cover or close the vents for letting in air into the attic. this will cause rot and mould