Mortar not hardening in damp weather

[kcflhrc]

Mix some Viagra with that Mortar

 

[s219]

Are you buying from Home Depot or Lowes? I'm struggling with the concept that either store has mortar on hand that's a year old, or with the sack from 2017, over 2 years old. Where I live, they rotate their stock and sell so much of it that there is always new stuff coming in. Just guessing, I don't think any of it sits for more then a month or two.

These were from Lowes. I never even thought to check dates but will be more careful in the future. Up to this point, the main problem I have had is sacks that were hardened. Last time I bought a pallet of concrete sacks from Lowes, the entire bottom two layers of sacks were hard as a rock. When I bought 8 sacks of concrete there a few weeks ago, the open pallet was all hard and I had to track down a worker to have them get a new pallet to pick from.

 

[drivesitfar]

s219: it might have been the date, but like I mentioned the suppliers for HD and Lowe's in our areas are known for putting in too much sand and not enough portland in the mortar mix. so in case you have a pallet of old bags and you might need to make a brick planter or some other non structural project maybe pick up a bag of Portland cement and add it to the bags current mix.

also DON'T put mortar on your lawn unless you want to kill it. LIME will make it turn green, but not necessarily healthier.

glad your new mortar was the fix!!

 

[Tractor Seabee]

Bagged stuff in spite of the plastic liner will absorb moisture into the product. Obviously the OP's first batch was already hydrated when he opened the bag. Storing cement on a concrete floor accelerates the absorption for some reason.

Side light, many years ago I was at an auction with my dad. They had a pallet of cement in bags about 6 bags high. Thumping the bags indicated it was solid a concrete. Guys were commenting "worthless already hard", my dad with only a 3rd grade education said let's check this out. he pulled out his trusty jackknife and probed some of the bottom bags, it wsa not hydrated just packed down from the weight of the product over time. He was the only bidder and he got the whole pallet for $25. We used every bit of it.

Ron

 

[s219]

Bagged stuff in spite of the plastic liner will absorb moisture into the product. Obviously the OP's first batch was already hydrated when he opened the bag. Storing cement on a concrete floor accelerates the absorption for some reason.

Side light, many years ago I was at an auction with my dad. They had a pallet of cement in bags about 6 bags high. Thumping the bags indicated it was solid a concrete. Guys were commenting "worthless already hard", my dad with only a 3rd grade education said let's check this out. he pulled out his trusty jackknife and probed some of the bottom bags, it wsa not hydrated just packed down from the weight of the product over time. He was the only bidder and he got the whole pallet for $25. We used every bit of it.

Ron

I have seen that with sacks on the bottom, and my test is to roll the bag sideways and see if the contents are loose and the bag changes shape again. Many are like that. One pallet I ordered, the bottom sacks were rock hard and solid, and had imprints from the pallet. Those were beyond hope. I really grumbled about returning them to the store since that was a lot of weight to tote back in, but it was $30-40 worth of material so I did it.

 

[Egon]

S219: congrats and guessing old mix didn't have enough Portland in it. if you have more bags of the old stuff laying around maybe buying a 60 or 94 bag of Portland cement would maybe be a good purchase and add a portion to each batch. i'm not 100% on this working, but thinking it should.

in any case you are back in business.

Adding extra Portland will work well. Premixed bags can always use a little help.

Or; a bag of mortar sand, Portland cement and some builders lime mixed so there is an over abundance of Portland but still nice and sticky. Gives you a better strength mortar.
In the original batch if the Portland had gone thru a chemical reaction there would be hard lumps in the bag.

also DON'T put mortar on your lawn unless you want to kill it. LIME will make it turn green, but not necessarily healthier.

glad your new mortar was the fix!![/QUOTE]

There is a difference between Agricultural lime and Construction lime.

 

[drivesitfar]

Egon: thanks for the clarity on the lime which is only a quick fix almost like painting a lawn green so to speak.

ALL: i've probably mixed a couple thousand bags by hand around here and a few have seemed like they were hard as a rock from being left out overnight or in the rain or for a few days. that said I've been able to use them all and yep maybe a little extra manual labor involved busting up the parts of the bags that had set, but after 30 years not a crack other than a few hairline ones in the sidewalks and pads i've made.

 

[bigtiller]

Adding extra Portland will work well. Premixed bags can always use a little help.

Or; a bag of mortar sand, Portland cement and some builders lime mixed so there is an over abundance of Portland but still nice and sticky. Gives you a better strength mortar.
In the original batch if the Portland had gone thru a chemical reaction there would be hard lumps in the bag.

Any idea how much Portland to add to a 60lb bag of premix?

 

[Egon]

About that much as experience will tell.

Sorta depends on what the mix looks like and it’s still sticky.

 

[bigtiller]

About that much as experience will tell.

Sorta depends on what the mix looks like and it’s still sticky.

If a guy doesn't have any experience and has only looked at a dozen or so in a lifetime, how much would you advise a good starting point to be?

Is a gallon to little? Is a cup to much?

Inquiring minds want to know.