Calculating U Values - wot the heck???????????? / Insulation

Ok

I'm converting part of my garage into a utility. All I get of BC i so long as it comes up to current regs. BUT the bstds wont tell me HOW to get it to current regs.

I have a single skin brick wall. How do I calc the U value to make it thermally efficient with my chosen method of studding and kingspan etc?

I will have a floor - same question.

Can anyone help?

100mm kingspan on the walls will do it no worry's. Can you get the same under the floor ?

Need to raise floor by nearly 200mm.

Can u advise of the spec for the walls?



The outside wall of the garage is single skin and I know I will have to improve insulation. I am unsure how to do this but wish to do so with timber frame and 75mm kingspan (you say 100mm). Could you advise of detail of breathers, vapour control and any air gaps?



Also I need to raise the floor.



My proposal is to raise the floor of the garage to the level of the kitchen via timber joists that rest on the existing concrete floor. The amount of raise is 200mm. I intend to pack in between the joists with jablite or kingspan but I am unsure of exactly how thick this should be. Also I am unsure of the addition of a second DPM. Clearly, the existing floor has a DPM.

1. Do I lay another DPM on the existing concrete floor and build up off that? Or do you advise another solution?

2. How thick should the jablite be? - Pack to the full depth or have an air space below and or above? If so how big an air space.

I intend to have 18mm chip or plyboard plus laminate flooring to finish above the timbers.

Please can you advise?

Thanks in advance

Brian

Do you already have 75mm kingspan ? this can be used but would mean clear cavity of 50mm would need to be formed. Does the floor need leveling up maybe you dont need joists and can install a floating floor on your insulation or maybe screed it .

No materials bought yet, this is just pub talk with the local wags.

I'm really looking for a spec from someone who knows what they are doing.

Floor.

I am confident at levelling and setting height if i use joists. dont want to use concrete / screed if i can help it

Cheers so far

Brian

Had a similar problem with my garage floor - had to raise the level by 190mm. I laid 170mm Jablite insulation straight onto the original garage base, then 1200g dpm layer and topped with 22mm t&g P5 chipboard flooring. That was 10 years ago and it's still perfect.

Just quoted for a flooring job and BC require 1200 membrane, 80mm Celotex or similar, 500g vapour barrier with 75mm screed with reinforced matting embedded within lower half of screed. Floor dimensions are 6 metres by 3 metres and it is domestic use.