Hot Tub Forum

Original => Hot Tub Forum => Topic started by: D.P. Roberts on September 25, 2007, 07:14:12 pm

Title: Curing concrete?
Post by: D.P. Roberts on September 25, 2007, 07:14:12 pm
I'm finally having my slab for our patio poured tomorrow. The concrete people said I need to wait a week at least before putting a hot tub on it. They said one week is the MINIMUM; they said it takes up to 28 days for the concrete to completely cure, so they recommend 28 days before putting something really heavy (like a hot tub) on it.

Is this typical? I can see waiting a week, but 28 days smacks of "CYA". It's just a 4" rebar-reinforced pad. I was going to wait two weeks anyway, but October is prime tubbin' weather here in Ohio, and I hate to wait two more weeks if I don't have to. Plus, as my namesake once said, I hate waiting.
Title: Re: Curing concrete?
Post by: Chad on September 25, 2007, 07:59:11 pm
Yes, what they recommended is "by the book". Is it neccessary? Imo, if it's over earth that hasn't been tampered with for a few years, then 2 weeks should be fine. FWIW, I waited the recommended 4 weeks and have had absolutely no problems at all now one year later. Not even any hair lines.....
Title: Re: Curing concrete?
Post by: D.P. Roberts on September 25, 2007, 08:06:09 pm
It's not old dirt- they're excavating out the old stuff and putting down a new 4" compacted stone base. Maybe we should wait.
Title: Re: Curing concrete?
Post by: Jacuzzi Jim on September 25, 2007, 08:08:10 pm
 We have set spas in less than 3 days with no problems,not our choice but a anxious spa owner, still there have been no issues I like to see at least 5 days.
Title: Re: Curing concrete?
Post by: Vinny on September 25, 2007, 08:18:18 pm
If you watch it, it dries faster and hader ...  ;D ;)
Title: Re: Curing concrete?
Post by: Jacuzzi Jim on September 25, 2007, 08:23:37 pm
 Get the wife to blow on it, it will get hard real fast!!   The concrete that is.   8-)
Title: Re: Curing concrete?
Post by: tony on September 25, 2007, 08:40:42 pm
Quote
I'm finally having my slab for our patio poured tomorrow. The concrete people said I need to wait a week at least before putting a hot tub on it. They said one week is the MINIMUM; they said it takes up to 28 days for the concrete to completely cure, so they recommend 28 days before putting something really heavy (like a hot tub) on it.

Is this typical? I can see waiting a week, but 28 days smacks of "CYA". It's just a 4" rebar-reinforced pad. I was going to wait two weeks anyway, but October is prime tubbin' weather here in Ohio, and I hate to wait two more weeks if I don't have to. Plus, as my namesake once said, I hate waiting.

The concrete people are technically correct.  It does take up to 28 days to completely cure the concrete, but you would most likely have no problem putting your hot tub on it in a week.  The concrete people are covering their butts.
Title: Re: Curing concrete?
Post by: Repeat_Offender on September 25, 2007, 09:33:12 pm
A week is plenty.
Title: Re: Curing concrete?
Post by: Cola on September 25, 2007, 09:47:20 pm
They can add a quick curing agent.  All contractors tell you this so that if or when it cracks, they have something to fall back on.  Concrete will cure for ever.  Not sure about exact specs but something like 60% strength in one week, 85% in 28 days, The CN tower was a continuous por from the bottom up back in the 70's and it still stands.  Heavy concrete poured upon freshly cures stuff.  Wait a few days to set the empty tub, a couple days for power then add water and don't worry about it, just my opinion
Steve.
Title: Re: Curing concrete?
Post by: Chad on September 25, 2007, 10:11:24 pm
I'm confused.
Are we talking about rest between football games or curing times of concrete?
Maybe we should have this moved to Bonniebelle's FOOTBALL thread in the BS forum. ;) ;D
Title: Re: Curing concrete?
Post by: Zep on September 25, 2007, 10:20:30 pm
let me first say, I am no expert, in fact I know alot less than most in here

BUT......
you have probably been shopping for a tub for months
you'll be soaking for the next 10 years
in the big picture what difference does a week or two really mean?

why get in a hurry & have a small chance of some nightmare?
let the concrete do what it supposed to do
relax.....give it a week at least, maybe two.
a month from now it will be long forgotten
and you'll be soaking to your heart's content
Title: Re: Curing concrete?
Post by: D.P. Roberts on September 26, 2007, 02:23:20 am
Quote
let me first say, I am no expert, in fact I know alot less than most in here

BUT......
you have probably been shopping for a tub for months
you'll be soaking for the next 10 years
in the big picture what difference does a week or two really mean?

why get in a hurry & have a small chance of some nightmare?
let the concrete do what it supposed to do
relax.....give it a week at least, maybe two.
a month from now it will be long forgotten
and you'll be soaking to your heart's content

Yeah, we're kind of thinking along the same lines. We're spending more on the patio than on the tub, so we really hate to risk screwing up the patio. We actually found this used spa months ago, another week or two won't hurt.

The post about the CN tower reminded me about the concrete in the Hoover Dam. It was poured more than 70 years ago, and some of the concrete still isn't fully cured. Now THAT is a long wait.
Title: Re: Curing concrete?
Post by: wmccall on September 26, 2007, 07:49:29 am
Quote
A week is plenty.

Mine cured a week. 5 years later, still looks like day 1.
Title: Re: Curing concrete?
Post by: tony on September 26, 2007, 08:27:35 am
Cola's info is pretty much on target.  The majority of curing takes place in the first week.  That pad can handle a lot more weight than a hot tub.  I just poured a pad for a trash dumpster and put it to use in a week and that involves a trash truck backing into it and lifting and dropping.  Even a house foundation only sits a week before the framers start.  28 days is a long time to wait, IMO.
Title: Re: Curing concrete?
Post by: Dr. Spa™ Ret. on September 26, 2007, 09:01:57 am
(http://www.samerb.com/cure.gif)
Title: Re: Curing concrete?
Post by: D.P. Roberts on September 26, 2007, 11:20:40 am
Quote
Cola's info is pretty much on target.  The majority of curing takes place in the first week.  That pad can handle a lot more weight than a hot tub.  I just poured a pad for a trash dumpster and put it to use in a week and that involves a trash truck backing into it and lifting and dropping.  Even a house foundation only sits a week before the framers start.  28 days is a long time to wait, IMO.

That's a good point about the house frame. I used to live in a development that was adding new houses on a daily basis, and I never saw them wait a month to start framing. And if I read Doc's graph correctly, it looks like the concrete is almost as strong as it's going to get after about two weeks.
Title: Re: Curing concrete?
Post by: webboy on September 26, 2007, 04:13:31 pm
Quote
I was going to wait two weeks anyway, but October is prime tubbin' weather here in Ohio, and I hate to wait two more weeks if I don't have to. Plus, as my namesake once said, I hate waiting.

If you just wait the two weeks that you where planning you should be fine, this cooler weather is best curing weather anyway, that's assuming its cooling off where you live. 2 weeks is one week longer than most people would wait anyway... :)