Most modern houses today now have solid concrete ground floors. These will typically be constructed using: –
Hardcore – a suitable filling material to make up the top soil removal and reduced level excavations.
Sand blinding – a layer of sand used to blind the top surface before the 1200 gauge DPM is placed down.
100 mm insulation sheets
100 mm concrete
50 to 75 mm screed.
It remains to be said that each set of plans may vary from architect to architect and the manner of construction they advise to follow may vary, but the above is pretty much standard construction so far as solid concrete floors are concerned. Years ago, it was not common practise to add insulation before pouring concrete whereas nowadays, you would not be allowed to proceed in laying a solid concrete floor in any living or dwelling space without the addition of it. Any BCO (Building Control Officer) will expect to see that you have or are using insulation in any new concrete floor that is to be laid.
I feel it also important to mention at this point that when you lay the DPM, it should be lapped up and over the course of bricks to where your DPC (Damp Proof Course) is to be laid. This will help prevent any chance of damp coming up from below. To finish the new concrete floor, if your designer has allowed for it, you will lay a 50 to 75 mm screed on top which will be trowelled closed. A 3:1 sand cement mix is typical for this with the addition of any additives.
The top screed will look great once laid but a word of warning! You will need to protect it with a covering until you are going to lay your final floor finish. Make sure you allow the floor to fully cure and dry out properly before covering it. Protecting the floor is particularly important if you are on a construction site and other trades are still working there. Once ladders start getting used on top of it and tools are moved around, it won’t take long before the screed starts getting damaged in places. If it does become damaged you can always use a self levelling compound to smooth it out but it is far better to protect the floor in the first instance.