Do you really need to insulate between the rafters ?

[JamesRees05]

Hi,
I'm going to be insulating my loft and I am wondering do I need to insulate between the rafters if I'm already insulating in between and over the joices to 300mm ?

Any feed back would be appreciative

 

[mointainwalker]

Insulating between both joists and rafters is a total waste of time and money.

 

[JamesRees05]

Why do u say that ?

 

[mointainwalker]

Becos its tru

 

[mointainwalker]

To expand on that last thought.

If you insulate the ceiling with 300 mm then very little heat will get through and there is therefore no point in expending money and effort to insulate the rafters trying to conserve that small amount of energy which will in any case serve very little purpose in a loft.

 

[tfish]

even if the loft is being used a habi room?

 

[^woody^]

Think about it .... why would you want rafter insulation to insulate a cold loft?

Insulate the used parts of the property via insulation at ceiling level, and leave the loft cold

 

[DevilDamo]

even if the loft is being used a habi room?

Then you would look at insulating between and under the rafters to comply with the u-values. Insulation at ceiling (which would then become the new floor) wouldn't therefore be essential but some acoustic insulation would be recommended to provide the necessary sound reduction between bedrooms, etc...