Update on that hot pour we did in Flagstaff last month

We had a big slab to finish and the sun was beating down, drying it way too fast. On a hunch, I grabbed a garden sprayer and filled it with a 50/50 mix of water and a little liquid dish soap. Giving the surface a light mist right before the final trowel pass kept it workable just long enough to get a slick finish without burning it in. Anyone else use something like this on a fast setting mix?

3 comments

3 Comments

fisher.adam12d ago

That soap trick is a good way to ruin the long term strength of the surface. You're basically putting a layer of weak, foamy junk right into the top coat where it needs to bond. I've seen slabs treated like that start dusting and scaling within a year. The right move is to plan your pour better or use a proper retarder, not kitchen sink chemistry.

king.andrew3d ago

Exactly. Saw the same thing on a garage floor a few years back. Guy used dish soap to slow the set so he could stamp it. Top layer just turned to powder, came right off when you swept it. That weak layer has no bond, so once water gets in there it's done. Total hack move that costs more to fix later.

bennett.riley12d ago

So what's the actual failure mode when it starts dusting? Is it just the surface flaking off, or does it go deeper into the slab?

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