Widespan v Hollowcore

Hi

Just looking for a bit of advice. We are building at the moment - blocks about to start and are trying to decide on where to get the first floor from.

We have a quote for 150mm widespan @ €31 sqm. Supplier has said we can lay our insulation directly on top, clip the underfloor pipes to it and pour screed without putting in any mesh.

The other quote we are considering is 150mm hollowcore @ €31 spm. We're waiting for the supplier to come back with details of what screed is needed on this although I have a vague memory of being told before that hollowcore does not need mesh in the screed either?

Are there any advantages to going with hollowcore over widespan? Or any drawbacks to either? We would really appreciate any advice.

thanks

Kate

One main difference is that 'most' hollowcore slabs require a 215 (9") block on flat as its supporting walls, whereas 'most' widespan slabs only require a 4" bearing. widespan slabs generally only require 9" bearing where two slabs meet on a load bearing wall.

Hollowcore can generally span wide distances and therein lies their advantage.

did you ask each supplier what bearing their slabs require?

Hi

Thanks for the reply. All our footings are 215mm so we're covered there.

k.

I put in 125mm prestressed widespan slab with 4" bearing at the inner leaf and 9" where slabs met.
I shuttered the outside of the slab and poured about 2" of 35n steel fibres concrete on top of that to get the floor level as it is very difficult to lay blocks directly on the slab without levelling it first. The skin also binds the slabs together to give in effect a composite slab which is very strong.
I then put a 6" soap on for all my walls external and internal. 60mm of kingspan was then put down and all the domestic and waste pipes butted thru the insulation. Then the mats for the UFH were layed and the all the pipes installed. Finally approx 80mm of concrete was poured to the top of the 6" soap to give finished floor. It was a lot of work but you could land an airplane on it!!!