Raising conctrete floor level

[vbpupil]

In my utility room i want to rais he floor level by about 3 and a half inches, what do i need to take into concideration when hightening a floor with concrete with regards to my dpc? may seem a silly question but ive never seen this done before. also would the concrete need reinforcement put in it? ie steel mesh?

 

[RedHerring2]

Needing to raise by 85mm is a bit in-between'ish.
Not enough for a layer of concrete and a layer of screed, and a little too much for just a screed.
Again, not quite enough for a layer of insulation and then screed.

For instance, a layer of concrete really needs to be about 50mm.
A layer of screed really needs to be about 40mm, or 65mm over insulation. (for normal sand/cement screed)

It may be possible to use a, say 30mm layer of insulation, then a 55mm liquid type of screed.

Or you could have a 50mm layer of concrete with a 35mm layer of sand/cement screed with additives.

I'm no expert, but perhaps my comments will encourage debate.

If you already have a dpm in the original floor, no additional dpm should be required.
If you have no dpm already there's ample opportunity to add one.
You souldn't need any mesh in the concrete.

 

[simeonosen]

Suggest RonaScreed 8 Day Overlay Mix 2.