Tried a new mortar mix and it crumbled like crazy

I picked up some pre-blended Type N mortar from a supplier in Denver last week and figured it would save me time. Mixed it up per the bag instructions and by day two the joints were already cracking and falling out. Called the supplier and they said the batch had too much lime in it lol. Now I'm back to mixing my own parts and checking the bags before I buy, anyone else run into bad pre-mix batches?

2 comments

2 Comments

uma_wilson791mo ago

Had a similar thing happen with a bag of Quikrete I grabbed from Home Depot two summers back. Mixed it up for a little retaining wall and it set up hard on the surface but the inside was sandy and loose. Took a hammer to it after a week and it broke apart like stale bread. Called the supplier and they blamed it on a bad pallet that got moisture in storage or something. Now I just buy my cement from a local masonry yard and check the lot numbers online. Also found out storing bags up on a pallet instead of concrete floor helps a ton.

thomas_roberts1mo ago

Wow, that's rough. I actually read something online last week about how some big brand premix batches have been going bad lately because they're adjusting the lime content to cut costs or whatever. Supposedly it makes the stuff look fine when you first spread it but then it doesn't hold up after it cures, which is exactly what you ran into. I always figured mixing your own was the way to go, especially for anything load bearing or structural, because you can see what's in the bag before you dump it in. It's a pain to measure out the sand and cement and lime yourself, but at least you know it's not gonna fall apart on you two days later. Good call on checking the bags from now on, that's something I'll start doing too after hearing about this kind of thing.