Few initial questions

[grahama]

Hi all,

My first foray into the building world, on a budget so want to do as much work myself as possible including sourcing materials.

Firstly,

what are the u values and how do they work, the higher the better??

secondly,

I am considering Crown diotherm slabs instead of Kingspan due to cost, which gives the better insulation for a total 100mm cavity filled fully.

I have read, I think, that the U value of CD slabs is .0034 and Kingspan is .0023, which is best??

Many thanks from a newbie, lots of questions to come I'm sure.

Graham

 

[stuart45]

Hi all,



what are the u values and how do they work, the higher the better??



Graham

Other way round, lower the better.

 

[grahama]

Have been doing some more reading and as you say I got it the wrong way round.

Is there a maximum figure for building regs, I will be doing the brick-dritherm (32)-thermalite block-plasterboard and skim method ??

Thanks,

Graham

 

[stuart45]

Each element of the building such as the walls, roof, floors, windows etc have a U value that should be bettered for regs.
However there can be a trade off if the insulation is increased in the other elements in some cases.

 

[^woody^]

U values are for a given element (eg a wall) and are made up from the k values of the individual components, and the wall is designed to achieve a certain u value by selecting certain materials, not just using a certain insulation

You can't use Kingspan in a full fill cavity.

Foil faced board such as Kingspan is roughly twice as efficient as quilt for a given thickness. But is also more difficult to use for cavity walls, especially for diy

 

[grahama]

Thanks for the help, didn't know kingspan and the like were not for full fill. What is the bldg reg document I obviously need to read please??

Graham

 

[^woody^]

It's not to do building regs. Its to do with the fact that it's solid sheet insulation and needs an air cavity