Concrete 101 Help

[geomarq]

I helped a friend pour and finish a 40' sidewalk yesterday and now have some questions for those with concrete/pool deck experience. I'm going to attempt my pool deck in the spring and this was a test for me.

- after the pour, screeding and initial float, how long do you wait for the next & final float? or when do you make your rounded edges and control joints?
- we waited roughly 45-60 minutes for the bleed water to settle.. then we did a final float, broom finish, then the edging and control joints
- only problem was the concrete was too hard IMO.. the edging and joint process was a pain in the a** as the cement was just too hard.. rocks kept pushing up and we had to mist the area frequently. There must be a trick to the timing of this.

 

[duraleigh]

The folks who do it for a living make it look easy because of the experience they have. Temperature is the most critical factor so the time will vary widely depending on the time of year.

The few times I have poured, I try to catch it just as it stops "weeping" on the surface but I have always been a little uneasy with that timing. My results have been OK but not great.

 

[JohnT]

It's very much a "feel" thing. We did a sidewalk once during a volunteer day at a park, and we waited and waited for it to set enough to edge it, and when it started it went faster than 3 of us could keep up with it. Had a concrete floor poured in my shop once, and one of the crew had to stay until 10:30pm because it wouldn't get right for the final troweling. I'll do a small area, but I call the pros when I need something big done because it can get away from you if you don't have the experience.

 

[Bama Rambler]

It is a "feel" thing. My dad and I (and a full crew) poured concrete for years when he was in the house building business and sometimes it'd go perfect and we'd be done and out in a few hours, and sometimes I've seen the sun come up the next morning waiting on it to "get right". As you can probably guess, I now have any large slabs contracted out so there's a crew of folks to handle the waiting part.

As John said, once it starts it can go really fast and that's when you need a full crew of folks that know what to do in order to stay ahead of it.