sub floor / screed

rodred

Hi,

just wondering if it is necessary to use a floor screed?
or can i put a 100mm poly insulation on top of the hardcore
and sand blinding, and then pour the concrete floor on that?

or is it better to have the concrete subfloor then insulation
then a screed on top of that??

what are the pro's and cons

soldsold

I just poured a 100mm finished floor with no subfloor, under the floor I have 300mm EPS 100 in 3 layers of 100mm with staggered joints.

1200 gauge polythene damp proof membrane/ radon protection went under the top EPS layer.

I also had to install all hot and cold water pipes, radiator pipes, cables for kitchen island lighting, waste water drainage, 4 inch pipe for toilets, etc under the top layer of EPS so I had to plan for radiator positions and the island position. This is probably the biggest issue with having a finished floor in place early in the build, having to make these decisions on locations of sinks and rad's early in the build when you are just looking at a flat hardcore base its hard to visualise everything

Mellor

soldsold wrote: »

I just poured a 100mm finished floor with no subfloor, under the floor I have 300mm EPS 100 in 3 layers of 100mm with staggered joints.

A 100mm slab is going to crack often, especially when on top on 300mm EPS.