Concrete slab & insulation

[chirpychippy]

Good morning,

I'm building a summer house, I've been advised I need a reinforced concrete slab for the base comprising of 150mm thick up to 225mm around the perimeter, ontop there will be two course of facing brickwork incorporating airbricks then the timber frame will built off of the bricks, that's the theory anyway.

How do I insulate the concrete slab, will I have to build a timber suspended floor and use celotex to achieve some form of barrier to the cold slab?

The concept of the airbricks is because I'm assuming I'll need to vent the suspended timber floor.

The reason for the face brickwork is because the vertical cladding has to be minimum 150 from the ground.

The spec for the summer house is 7mtrs x 4mtrs x 2.5 high, it is next to a boundary.

Thank you.

 

[Deluks]

It seems a bit heavy duty for a timber framed structure.
You can float the insulation and floor on the concrete slab. No airbricks required.

If you go for a suspended floor you can sack off the concrete slab altogether. Airbricks required.

 

[chirpychippy]

This is the issue, I don't know anything about concrete, I'm building this for my in-laws and the father in law is over me like a hawk, so I'm thinking slab, I spoke to a builder who quoted £4440 for machines, muckaway, shuttering and reinforced slab, I thought that was alone was excessive...

 

[Deluks]

I don't think the price is excessive, but the spec is.
Although if you are paying someone then you'll have to price up your options. What the soil type?
If not on heavy clay or rubbish, then a simple strip foundation would do ok for a dwarf wall.
You need more quotes, and a second opinion.

Tell the FIL if he doesn't trust you then he can organise it all himself.

 

[stevie888]

I think you need a proper design tht you can then build: better all round.

I agree with Deluks your propsal ott.

 

[noseall]

Good morning,

I'm building a summer house, I've been advised I need a reinforced concrete slab for the base comprising of 150mm thick up to 225mm around the perimeter, ontop there will be two course of facing brickwork incorporating airbricks then the timber frame will built off of the bricks, that's the theory anyway.

How do I insulate the concrete slab, will I have to build a timber suspended floor and use celotex to achieve some form of barrier to the cold slab?

The concept of the airbricks is because I'm assuming I'll need to vent the suspended timber floor.

The reason for the face brickwork is because the vertical cladding has to be minimum 150 from the ground.

The spec for the summer house is 7mtrs x 4mtrs x 2.5 high, it is next to a boundary.

Thank you.

Would you not be better off on a strip foundation?

 

[chirpychippy]

Would you not be better off on a strip foundation?

I expect you are correct, for some reason I always think "slab" but strip foundation seems sensible. I was also pondering reinforced concrete piers but that creates different problems...