i have a few basic 80.lb bags of Sakrete concrete mix and mortar mix
these bags are unopened but are about one year old. does this have a shelf life or must they be fresh for best results

thanks

 

As far as I know..... there is no shelf life.

If the mix was no good it would be solid as a rock from air and moisture leaking in.

 

Not a pro on this, but I mixed up a few bags of year old sakrete for a small adjustment and it just did not firm up. My conclusion is that the concrete powder in the mix begins to harden, these bags were partially hard, and all the banging you think is restoring it for use is just creating small chunks of already cured concrete. In that state it never goes back to binding the aggregate as it should. Had to dig it all out and start over.

If they have been stored in a dry low humidity environment, maybe. Lets see what the pros say.

Bud

 

If I come across a bag that is partially hard...... it's either "out the door" or used as fill.

I've seen people chop the hardened cement and mix it in and you're right.... it never sets right.

 

Most manufacturers of pre-packaged concrete mixes use tiny perforations in the bags as an aid in filling them with product; the holes allow air to escape while the product is dumped in on an assembly line in a matter of seconds. Unfortunately, those same tiny holes enable moisture in the air to enter the bag over a period of time, allowing it to hydrate with the Portland cement in the mix and become hard.

About the only way I know of to prevent hardening of a partial bag is to empty it into a 5-gal. plastic bucket, and keep it covered with a tightly sealing lid. I've used such stored amounts of Quikrete more than a year after opening the bag, and the stuff still set up and worked as it should. That's saying a lot, as central Oregon where I live has a fairly humid climate.

 

It has been my experience that bagged cement products, concrete, cement, grout, thinset etc. do not store well for more than just a few months. The stuff is so cheap why take the chance?

 

Furd, your definition of cheap may differ (considerably) than most of us poor blokes who are barely getting by. Any opportunity to not waste construction products should both be explored and utilized, when one is hard-pressed to put adequate food on the table. Or keep good shoes on the kids, or even send them to school not looking like rag-a-muffins. Who knows--$5 here, and $5 there, and before long you're talking about real money (at least enough to enjoy a rare meal out once in a while).

And then there are the environmental consequences--filling the landfills with hardened Sakrete or Quikrete is not exactly taking good care of our planet.

 

You can safely include me in that group of poor blokes. I'm retired and although I do have a halfway decent pension along with Social Security I am far from even well-off, let alone rich.

What I mean by too cheap to take a chance is that if you invest in a few hundred dollars (or more) in materials for a tile floor along with your time, do you REALLY want to jeopardize that by attempting to use some thinset or grout that has been sitting in the garage for several years? This is the exact situation I am in as I bought all the materials to redo my bathroom floor several years ago but for reasons and excuses that I won't go into I have never gotten any farther than stripping the old tile and thinset from the floor. I have no doubt that the Hardibacker I bought is still good, the tile of course is fine, the seam tape (for the Hardibacker) should not have gone bad nor the screws but the thinset and the grout I have serious reservations over. For the cost of a bag of each I refuse to take the chance.

And your comment about taking care of the planet is asinine. What would you propose I do with the materials that are no longer suitable for their intended use? I DO have an alternative, one that I used at my old house when I had a couple of sacks of redi-mix that went bad. I used them as back-fill in a retaining wall project. Remember too that nothing decomposes in a sanitary landfill. I'd rather be digging up a landfill a couple of hundred years in the future and come across some hardened concrete products than a pile of used diapers or a bag of dog manure.

 

you guys remind me of sen dirkson's comment - a few million here, a few million there - pretty soon we're talkin' about some REAL $$$,,, as I recall.

we don't save bagg'd conc,,, unused gets rtd OR I toss it,,, far's the planet's concerned, this stuff originally came from the planet - we're just helpin' it relocate to a better 'hood.

how much's a happy meal now ? OVER $5 here,,, figger as long as there's wtr in bsmts & crk'd conc, there'll be no poor blokes in either home