Building terminology & specification queries....

[Pickup]

Hi Folks,

got some queries on terminology & specifications which I'd be grateful if someone could answer/clarify for me.

"the sole plate anchor is laid above the DPC, lined up and shot fired into the concrete base" - what does SHOT FIRED mean (nail gunned??)?

Insulation in a concrete floor slab "Extruded Polyurethane Rigid Insulation" should this be Expanded Polystyrene Insulation (XEPS)?

Are "Breather paper" (timber frame construction) and "Breather membrane" (roof construction) the same thing / is there a product that can do both?

Concrete slab for a 2 x 1.5 m porch - is a 100mm C35 concrete slab with A142 mesh on 100mm insulation / DPM / 50mm sand / 150mm compacted hardcore overspecified - if so would C30 without the mesh but with the hardcore etc be adequate?

Any reason why C35 - 2:3:5 (Cement/Sand/Fine Aggregate) cannot be mixed on site?

Thanks

F

 

[noseall]

"the sole plate anchor is laid above the DPC, lined up and shot fired into the concrete base" - what does SHOT FIRED mean (nail gunned??)?

Yes. Or you can plug and screw or use concrete screws.

Insulation in a concrete floor slab "Extruded Polyurethane Rigid Insulation" should this be Expanded Polystyrene Insulation (XEPS)?F

It sounds as though he is specifying PIR foam board to me I.e celotex, kingspan etc.

Are "Breather paper" (timber frame construction) and "Breather membrane" (roof construction) the same thing / is there a product that can do both?

Building paper and breather membrane are two different things. Breather membrane is a universal waterproof covering that allows water vapour to escape and will be suitable for wrapping most structures.

Concrete slab for a 2 x 1.5 m porch - is a 100mm C35 concrete slab with A142 mesh on 100mm insulation / DPM / 50mm sand / 150mm compacted hardcore overspecified - if so would C30 without the mesh but with the hardcore etc be adequate?

Any reason why C35 - 2:3:5 (Cement/Sand/Fine Aggregate) cannot be mixed on site?

Thanks

F

I have no idea why mesh has been specced other than you must have very poor ground. Yes, you can mix your own concrete.

 

[Pickup]

THANKS Noseall,

We were surprised at the spec for the slab, especially when I read elsewhere that C35 was "(industrial strength) Structural concrete for major construction work and roadways"

The ground is - I think - good... compacted hardcore (the gravel driveway runs up the side of the house and previous porches were constructed on this) down to about 1400 mm and then firm, natural, base sandy/stony/ rock. No clay or anything I think I should be concerned about.

I suspect, from a couple of errors I found on early drafts, the plans were either for something much bigger and just tweaked or a copy & paste job of relevant text.

Thanks again.

F

 

[noseall]

Typical of an over zealous architect or a lazy one.

Ridiculous spec for a small porch.