I realize the correct ansewer probably involves a calcium chloride test, but generally speaking how long should a new concrete slab be allowed to cure before stain is applied?
28 days is a generally accepted rule for conc to cure but no one really knows,,, it's 1 of the test periods for conc strength & has been adopted as a timeline for staining,,, since stainers usually need 2 days to load their trucks, its been convert'd to 30 days for them,,, if you know what you're doing, earler's ok, tho.
best [the original] where'd-i-put-my-keys-to-the-truck yic-yac
Thanks. I'm very familiar with general concrete curing, just didn't know how loong to wait for stain. I do know that a fresh slab will give off a lot of moisutre, which surprises many people when they pour a basement slab in a finished house, and wonder why the bottom of the joists are suddenly condensing.
no, the answer is not a calcium chloride test.
the time it takes for excess mix water in concrete to evaporate is pretty consistent, as long as you didn't use a cheap contractor who watered down the mix.
it ranges from a month to 12 weeks, depending on the type of sealer you're going to use. outside, with an acrylic, you can seal after a month in most cases. inside or outside, with a urethane or epoxy, it's more like 12 weeks.
you can stain before 28 days, but what's the point? the concrete has not even reached 75% of its strength and you cannot seal it. plus, for that whole period you're likely to have efflorscence rising up and discoloring the surface.
so wait the 28 days. if there is no efflorescence, then go ahead and stain. don't bother testing the concrete. calcium chloride tests are useless anyway. they only test the top 1/2" of the concrete.
concrete products magazine just had a couple studies written up about how useless and ineffective calcium chloride tests really are. just don't tell that to the testing companies who have millions of these on hand.
[quote name="usconc" time="2008-04-11 16:40:35"] how useless and ineffective calcium chloride tests really are.[/quote]
Blaspheme! How can you say such a thing. :)
It turns out she used a "facory certified" installed for Stamp Crete, and they poured one day, stained and sealed the next. I looked at the web site and tried to find some application instructions. They are a little vague, apparntly you're supposed to trust the installer to do it right. But I did find something in there where they sugest that the stain and sealer shoudl be applied the same day, as soon as the bleed water has settled.
staining and sealing the same day? i've never heard that before. the floor wouldn't be dry enough for one, and two, the color wouldn't be fully developed.
but imo that's something to be expected from stampcrete. as far as i have been able to discern, they are not a real "player" in the decorative concrete industry. i don't know any contractors that use their product. just disgruntled former contractors complaining about exorbitant startup fees and poor product quality.
maybe someone here can tell us otherwise about their experience with the company, but those kind of instructions for staining are just irresponsible.
I've seen some training video's and documentation that suggests a minimum of two weeks drying prior to staining. They also recommend 28 days before sealing. As previously stated, I wouldn't stain unless I could seal within a day or two.
here it goes again,
Every contractor has his/her method. Most manufactures recommend 28 days.
The issue most people always bring up is sealing. I agree it can be an issue however it should not cause a problem if the right sealer is used.
Around our area a lot of contractors that pour pads use a cure and seal the DAY OF POUR to help in the curing process.
CURE and SEAL is a sealer. Around here it is commen to use Sonneborne CURE AND SEAL 30% solids acrylic. Again this is the DAY OF POUR.
Stain does NOT weaken the concrete. PERIOD show me a study (written) that proves otherwise. Sealing with one coat of an acrylic solids sealer (OR CURE and SEAL which they are some times referred to) should not be an issue as long as a few days have passed......how many? this comes from experience. The hardest thing staining early is knowing how to dilute the stain as greener concrete stains darker.
We have stained thousands of square feet early and never one issue.
I respect other opinions that say otherwise but forcing an opionon as fact causes issues some times.
There is no TONE here. Everyone that has posted above is an expert however opinions vary on this. I am still looking on a tested proof that early stained concrete could be bad?
Educate us here? Anyone?
I have acid stained as early as two days after the pour with good results, We do not seal until late in the project, usually 3 to six months after staining.
How do you go about staining a slab that has had a cure and seal applied? What prep is necessary to profile the slab to accept the stain?
up north where the winters are harsh and salt is used i always sprayed cure and seal right after i broomed it and after i washed the powder release on stamp i would dry it with a leaf blower then use it there also .never had a problem.i now live in the fort worth area and have tried alot of sealers and have found that only the cure and seal work without problems.i drive out of my way to dallas to buy it.when i stain i wash it the next day or two then seal it up.i like to wait at least 3-4 weeks to stain myself .summer here being 100 degrees or more maybe 2-3 weeks
Copyright © 2010 Decorative Concrete Forums Inc. All rights reserved. Any duplication of any content is strictly prohibited without written consent.Find Stamped Concrete Contractors, Acid Stain Contractors, Concrete Countertops, Polished Concrete and Concrete Overlay contractors