Liquid DPM -> then screed -> then self levelling compound

[speakermonkey]

I am in the process of converting my 8.5m x 3m garage into a home workshop. The floor is old concrete and dips ~25mm in the middle.

My plan so far was:
- fix up any cracks and dodgy bits in the current concrete floor
- lay a liquid dpm
- finish with a self levelling compound

I spoke to Everbuild/Sika and they were able to recommend a DPM paint and compound that would bond together, by priming the final layer of dpm with sand. My problem is, I will end up spending about a grand on the SLC, not something I have the budget for really.

I then considered laying a layer of screed to take up most of the depth and finish with SLC. However, I don't have the headroom in the garage for a thick layer of screed as I believe the min. thickness is around 50mm (?).

Can I bulk out the SLC with sand or is there a screed mix that can be laid thinner?

I'm not after a perfect-perfect level floor as I will be laying a rubber workshop matting over the top to be easy on the feet.

Any input appreciated.

 

[Mr Chibs]

Liquid screeds can be laid thinner than 50mm, so I'm told... but they are not the cheapest... if you can find someone with a concrete pump, you might be able to do a 'deal', you wouldn't need to fill any dodgy bits.

Don't think you can bulk out SLC without making it weaker, but willing to be proved wrong.

 

[23vc]

I didn’t think bulking out SLC with (sharp) sand weakened it, I thought the manufacturer stated it was ok, just that it’s no longer self levelling