Masonry cement gone bad?

[Tig]

I had six bags of masonry cement left over from bricking my place. They have been on a skid in the garage for the past 20 months. Dry, with a plastic sheet draped over them, but it is quite humid here in general.
I'm installing a corner shower and the instructions said to set the base in a mound of mortar for added support. So I opened a bag, it had a few soft lumps but no hard crumbs. Mixed it 3:1 (didn't have any portland to add) and I built a base for the mound yesterday Today I have that uh oh feeling. It did set, sort of, but stray lumps simply turn to dry powder when pinched lightly. It's been 20 hours, the mound is 3" high.
In retrospect I'm quite annoyed with myself on several levels. If someone else had built a 3" mortar mound as a base and used old left overs to boot, I'd be hard pressed to not roll my eyes.
I'm going to avoid mirrors till I get this done properly.........

 

[dave1949]

Maybe give it another day? Watched pots never boil and watched mortar never sets. Anyways, you will know for sure in another 24 hours. Until then, relax, it is out of your control. If it doesn't harden, it won't be any more difficult to remove than it is now.

 

[s78wingrider]

Thing it's only good 1 year

 

[studor]

Most bagged cement has an expiry date -- even in super dry conditions it will go off and usually within about three months. Like you I learned my lesson the hard way. Best to just take it out and start over -- JMHO

 

[Western]

Hey Tig There ya go!! Is there any way you could get it out?? If so, might save you many nights laying there thinking...........Drop in shower, you may be fine, but if it degrades over time???

I've used 2 year old bagged sakrete for fence post and had no problems, but it was a fence.

 

[Soundguy]

i've use bags of sackrete that were over a year old. never had an issue with them.. un;less you let them get wet and they turn to paper covered rocks....

 

[Tig]

The only thing worse than screwing up a job would be pretending that I didn't. I've lost confidence in my little stash of masonry cement. Seems that something has gone wrong. There is no plastic liner to the bags, just paper. Glad I did this in two steps so I could let the first part set before I dropped the base on a top layer. Doing it in one step would have hidden the flaw, for now.
To do it over I would lay a few bricks under the base to displace most of the prescribed mortar mound. I'll get at that later this week.
On the bright side looks like I can move the last 6 or so bags to the soon to be filled basement. They were a nuisance in the garage anyway.

 

[Western]

I haven't bought cement in a while that didn't have the plastic liner, that probably shortens the work life considerably.

"On the bright side looks like I can move the last 6 or so bags to the soon to be filled basement. They were a nuisance in the garage anyway. "
See, it has a "silver lining" anyhoo:thumbsup: I wonder if adding a fortifier would increase the strength of the cement?? Probably not worth risking though to save $20 for new sakrete.

 

[dave1949]

Tig, How did your shower pan bedding work out?

 

[Paddy]

Tig,

There are a couple of things here. First, I never understood the point of making a motor mound. It would crush over time. I did it the first time and it sounded like gravel 6 months later. In this home just built, I came from the side and glued in treated wood wedges at several key points. Now it feels real solid and no squeaks or crunching gravel.

The problem I think happened is the plywood base sucks the water out before the chem action can occur. Thus the crumbing. same is true with setting brick and block, if the block is dry it will pull the water out. They always recommend wetting the blocks and keeping it wet. That is hard to do on OSB.

Cement can go bad. We use a portland cement in our factory. We do incoming inspection strength tests before using. It is all time stamped and controlled very closely. But like I said, I don't think that was your problem.