I had planned to find a nook in the low-humidity house in which to shove it, but it would be interesting to know how long the bag will keep in various humidities.

The main question is: How long can I store a (new, sealed) bag of Quikrete in the house with central AC and heat?

I don't expect there to be a perfect answer to this question, so I'll upvote any useful insight (ie "I kept a bag for X years and it was fine" or "I kept a bag for X years in the garage and it turned to a brick").

  • 1
    I had 4 bags stored in my garage, I thought I would be able to use it if it hadn't turned into a brick. It was hard but I opened a bag and it was still somewhat "powdery" so I mixed it up for setting a Mailbox Post. A day or so later the post was still not set. The little extra pieces were not hard and crumbly. So, I guess it does have a shelf life, even when not hardened.
    – George
    Jun 14, 2016 at 14:23
  • Ask Jimmy Hoffa !
    – Alaska Man
    Apr 28, 2019 at 21:54
  • it would be nice to change the word "Quikrete" into "mortar" (for those who never heard of it).
    – JinSnow
    Apr 5, 2020 at 17:05

7 Answers 7


Depends on how exactly you store it. If you want to keep it around as long as possible without becoming a brick, put it in a seal-able plastic tub with desiccant packs and keep it in your house (as you said you were).

Too much effort in my opinion. Just take it back to the store, get your money back, and repurchase a new bag in the future when needed.

I've had bad experiences with them turning into bricks in a high-humidity basement; took about 6 months for it to happen.

  • Well, its $3 for the bag and the drive to the store to return it would cost at least the $3 in gas. I thought I may use it in the future, but have no current plans of how yet.
    – Randy
    Jun 28, 2013 at 19:00
  • 2
    No need to make a special trip. Just make it part of your daily trip to Lowe's :) Jun 28, 2013 at 19:17
  • I would, but the problem is I bought it at Ace :p
    – Randy
    Jun 29, 2013 at 0:50
  • some won't "turn into bricks" but just won't work (you could break the result with a finger).
    – JinSnow
    Apr 5, 2020 at 17:02

I live in the Pacific Northwest. A bag in my garage turned into a brick after just one summer to winter to summer transition.

  • Sounds about right in the land of rain where people rust instead of tan. It starts clumping towards midwinter. I actually salvaged it with a sledge hammer and screening as it was a low strength application. Lotta work for little return. Buy only what you need unless you have a really dry storage area. Amazingly, the Bentonite HoleShot didn't get affected by the humidity (4 winters now). That stuff swells to 20-30 times its size when it gets wet. Jun 28, 2013 at 5:58
  • So, even after it turns to brick, you can bust it up and use it for something like a post hole?
    – Randy
    Jun 28, 2013 at 18:58
  • If it hasn't thoroughly set, yes. It doesn't necessarily evenly absorb moisture. You can have an outer shell that ends up being aggregate that can be fused together by the remaining Portland Cement that has been minimally hydrated. Not something you want in your foundation where strength is needed. Also wear a dust mask, you don't want cement lung. Jun 29, 2013 at 5:07

I got a 60 pound bag of concrete donated to me by a neighbor. I have no idea how old it was, like how long he had it. I used it to set a metal sculpture -- a pole, really, like you would set a fencepost, in a big hole with a few big stones to take up a lot of the space. The stuff mixed just fine and had a nice slump to it and poured no problem, vibrated nicely into the interstices of the stones. And then it never set up! It's soft. It acts like concrete that's just been poured and is starting to set up, but it seems like it's never going to set up. It's been days. So my advice is that there's only one kind of bagged concrete to use, and that's a new bag from a busy store.


I just used a bag that was 10 years old. Set up beautifully! Stored in a heated garage. Dry climate.


Cement is nothing more than a bag of DRY chemicals! So dry, that it wants to suck in moisture any way it can! once the bag is opened, you better find a good way to keep moisture out other then rolling down the open part of the bag, and call it good. There is a reason that the cement bag has a plastic liner! Once that bag is opened,...it's on borrowed time, unless of course your going to use it within a FEW weeks. Water (or moisture), will activate the chemicals as we all know...moisture will work more slowly, but it's like brown sugar...that also will turn into a brick if exposed to moisture for too long. Use it or lose it....


In our attached garage I have a bag that is a few years old that still works fine on small projects. In the detached garage there is a bag that is also a few years old that is as hard as, well, cement! Likely the difference in heat and humidity since the attached garage will get some heat from the house, while the detached garage has none.


I’ve got an open bag of postcrete (which I presume is similar?) in the garage; it’s been there a few years and is fine. I folded down the top and clipped it. I’m in the U.K. The garage isn’t attached to the house and isn’t heated. But we don’t have moisture problems in there.

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