Right, there are a number of variables to take into account here.
First off, that the SLC lost the bond to the sub floor suggests that you either chose the wrong SLC (which doesn't appear to be the case this time), or that you didn't prep the floor properly. Either could also be the cause of the cracking, but one thing at a time.
- Did you rough the surface of the quarries?
- Did you prime the quarries?
- What the substrate beneath the quarries sound?
That the SLC cracked suggests either faulty preparation, application, mixing, or drying.
- To what thickness did you pour? 1-10mm is the normal range for this product.
- Did you complete the whole surface in the open time of the product? (20-30 minutes)
- Was the surface exposed to sunlight?
- The temperature of the air AND the substrate within normal working range? (5-35 degrees c)
- Is there rising damp where you applied it?
- Did you let the mix slack for 2-3 minutes before remixing and applying it?
- Were your tools and buckets (relatively) clean before you used them?
Here are the
specs for Mapei Ultraplan Eco.
Using SLC is not as simple as it seems. You have to be absolutley sure that you pick a suitable product, and there are many many variables to take into account.
- Is it inside or outside?
- Is there rising damp?
- Will it be exposed to water?
- Can it be tanked?
- Does the tanking product allow for diffusion (only if required)
- What is the substrate made from?
- Is it sound and stable?
- Are there and cracks or gaps in need of mending?
- Is is the substrate clean?
- Will I need to abrade it?
- Prime it?
- Slurry it?
- How thick will I need to make the leveling layer?
- Do I need to reinforce it with rebar netting?
- Mix it with sand?
- Mix it with flex additive?
- Will it cope with the stresses of what it's going to be exposed to in the intended environment?
- What working and drying times does it have?
- Will I need to take extra precautions when it's drying, such as watering it and covering it?
- What will I put on the finished surface?
- Does the specs of my chosen SLC fit the bill?
- And more...
Always, and I cannot emphasize this enough, ALWAYS read the product specs thouroghly before use, or you might end up with lots of lost time and money.
If in doubt, call or mail the manufacturer, or their agent.