Insulating a loft

exiled_red

I have just bought a house and am looking to insulate the loft, I have read a fair bit about insulating using loft roll between the joists. This seems to mean that the heat is kept in the house and as a result there are fairly large temperature variations in the loft in summer and winter, I am wanting to store some stuff in the loft that will not do well in with large temperature fluctuations. I have read that you can do rafter insulation presumably as well as normal loft insulation but I am wondering how well this works, if anyone has done this? what they did? and what the temperature variations are like?

Hong_Kong_Phooey.

exiled_red wrote: »

I have just bought a house and am looking to insulate the loft, I have read a fair bit about insulating using loft roll between the joists. This seems to mean that the heat is kept in the house and as a result there are fairly large temperature variations in the loft in summer and winter, I am wanting to store some stuff in the loft that will not do well in with large temperature fluctuations. I have read that you can do rafter insulation presumably as well as normal loft insulation but I am wondering how well this works, if anyone has done this? what they did? and what the temperature variations are like?

Then the lofts not the place to keep it.

exiled_red

Hong_Kong_Phooey. wrote: »

Then the lofts not the place to keep it.

The idea is that appropriately insulated there shouldn't be large temperature fluctuations. That's why I'm asking

MX5huggy

You can insulate at the rafters it's more expensive, and complicated to do properly. It's what you would do if doing a full loft conversion.

One link :- http://blog.kingspaninsulation.co.uk/how-to-insulate-a-pitched-roof-at-rafter-level/

Don't be tempted by multi foil products.

Ebe_Scrooge

exiled_red wrote: »

The idea is that appropriately insulated there shouldn't be large temperature fluctuations. That's why I'm asking

No, the idea is that appropriately insulated, there WILL be large temperature fluctuations in the loft. It will be boiling hot in summer, freezing cold in winter - the idea is to keep the house at a reasonably constant temperature. Indeed, that's why you have to be careful about water tanks in the loft - they could freeze in winter if there is insulation directly under them. As per the above replies, a standard "properly insulated" loft is not the place to be storing anything that is sensitive to temperature fluctuations.

exiled_red

My thinking is that if you insulate at roof level rather than between the ceiling of the house and the floor of the loft you can keep the temperature fluctuations to a minimum, the down side is obviously that you are paying to heat the loft. Which seems to be what MX5huggy was suggesting, the other places that I have read have suggested insulating at the roof and at the loft floor which I don't see working because the insulation stops the loft from being warmed by drawing heat from the house (which is what most people want)

Furts

If you are going for a Celotex type board then follow the manufacturers technical data. It will be fiddly, there will need to be ventilation. you need to consider what material is used on your existing felt, you may need a vapour barrier, so it does get technical. But you also have to consider will your loft take the weight of your stored items, and how you access these items across the bedroom ceiling.

Celotex boards are not cheap and you will struggle to get decent insulation. All round there are many reasons why builders put loft insulation as fibreglass placed directly over the bedroom ceilings.

exiled_red

If you use these types of boards do you have some insulation at floor level in the loft or is this counter productive?

Furts

It is your choice on what you are trying to achieve. In principle if you put Celotex boards at ceiling level you will be making your loft colder in winter and hotter in summer and this is running counter to what you want.

You need the insulation at rafter level, but this is going to need careful design, and careful installation. Add to this it will not be cheap, and your heating bills will be higher, simple . You still will not get a perfect environment, and ventilation, condensation, and control have to be considered.

You have not said what you want to store, nor why temperature variation is a concern. A quick answer is to store these items in a bedroom where better conditions exist.