Question about a small batch of concrete I mixed with a splash of dish soap last week

I was trying to get a super smooth finish on a small patio slab in my backyard, so I added maybe a quarter cup of blue Dawn to the mix (which I heard could help with workability), but it ended up setting way slower and left a weird, almost foamy surface that I had to grind down.

2 comments

2 Comments

the_hayden20h ago

Is it really that bad every time? I've seen guys add a tiny bit of liquid soap to mortar for brickwork to make it creamier, and it worked fine. The problem might be using too much, or the exact type of soap. @troy832's story about the laundry powder sounds like a total mess, but a quarter cup in a whole batch seems like a lot. Maybe it's more about the dose than the idea itself. I'd try it again on a test patch with just a few drops before writing it off completely.

troy83220h ago

Yeah, that Dawn trick is a total gamble. I mean, my uncle tried something like that years ago on a shed base, but he used laundry detergent powder. It basically stopped it from setting right, like it just stayed this damp, crumbly mess for weeks. We ended up having to break the whole thing out with a sledgehammer. It's one of those old-timer tips that seems to work for some people and totally ruins it for others, and you never know which it'll be until it's too late.