Leveling a set concrete pad before dpm

[R1plusR2]

Hi peeps

 

So heres my first topic, sorry its a bit of a basic one.

 

We had the 100mm base poured in our kitchen extension at the start of our project. I am now at the point of putting in the insulation and underfloor heating. We made some bad choices on a builder so i have a few knock on effects to deal with.

 

The concrete pad was pumped and tampered with a rake and runs out 25-60mm in places according to my laser level. Plus you can see it by eye. So basically its not smooth or level. In my eyes theres a massive risk the dpm will pierce.

 

The floor buildup on spec

 

50-60mm liquid screed

Underfloor heating (wet) stapled

1200G DPM

100mm insulation

1200g DPM turned up and joined at dpc walls

100mm concrete pad

 

Usually if its hardcore it would be sand blinded, but as its a dpm on top of a pad, should i just blind and compact/level it that way anyway?

 

Id like to get it nice and level for an even screed thickness.

[Declan52]

Just put sharp sand down on top of the concrete and level it using a straight edge and your laser level. Then just continue on with how you had it planned out. Don't forget edge insulation.

[R1plusR2]

Hi Decal52

 

Thank you for the response.

 

Right so i am on the right track there. After leveling off is there any need for compaction? Im thinking this would be a bad idea as its solid under it so it cant really go anywhere, i could hand tamp it. Normal practice obviously it would if it were on top of mot1 or subgrade.

 

I have got 25mm pir kingspan for the perimiter edges/upstands. I was told these dont need to be level as its best to trim excess off later after screed? So think i will do that.

[Declan52]

No point in getting a Wacker for that. Just walk over it constantly digging your heels in. Aim for 10mm more than you need then tramp it in, level it off and add to any low bits until it's smooth and level.

[R1plusR2]

Brill. Thats great.

 

Thanks for the help!!