Applying mortar to concrete blocks

I am struggling getting mortar to stick to the blocks - when I try to do the sides, the mortar just falls off. Any suggestions?

Hi John,

It’s a bit of an art, as you’re finding. Very wet mortar will slip off, and very dry mortar will be too difficult to spread. So an obvious part of your solution is to make sure your mortar consistency is somewhere between those two extremes.

You can also try spraying down your blocks with water and giving them a few minutes to soak it up.

Your best bet is the water-to-material mix of your mortar. Once you find the sweet spot, you’ll know it almost by feel.

Thanks for the response.
I’ve gone through two 60-lb bags and tried a variety of mixing techniques, mixing time lengths and water:mix ratios. I have tried paddle mixer, cement mixer, and mixing by hand. I have watched about 10 youtube videos on the topic, and it just doesn’t get to the “peanut-butter” texture/stickiness, which is necessary to get mortar to stick to sides/bottoms of blocks on first layer. I felt like I was close once, but only a couple trowelfuls stuck. I guess I just foolishly assumed this was something anyone could do (especially with the “just add water” legend on the Quikrete bag).
Anyway, sorry to vent, but this part has definitely been the most frustrating.

Okay. Take a breath. And know most of us have been through this too.

An alternate technique is to lay mortar for the bottom of the block, set it in place, and then use your trowel to “slide” mortar down one side of the block. This is technically “pointing” the joint. It will be a little sloppier than buttering it, but it will work.

Once you have the joint filled, use the point of your trowel to smooth the joint (up-strokes only) and it will look just as though you had buttered it.

You should also keep in mind that the mortar is meant to make a solid surface from the block components. The real strength will come from the concrete you pour into the voids.

Keep us posted and good luck!

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Bikerbudmatt, Belated thanks for the response. Putting the mortar down first helped. The first layer wasn’t pretty but my mortar consistency did get better - when I stopped giving a sh*t and “got on with it” . :grinning:
I was dreading the high-temp mortar mix (for standard brick on top of the base), but this turned out to be much easier. Not sure if that was because my skills were improved from messing with the regular mortar for so long, or if there is an inherent difference in ease of use.


You cracked me up, John!

I’m glad it worked out for you. Yes, the heat resistant mortar is easier to stick and “stay stuck.” I can’t put my hands on it right now, but I recall watching a guy on YouTube demonstrating everything he knew about making a concrete block wall. He was amazing to watch—quick! agile! neat!— and I had to keep reminding myself he was a pro who had been doing this for a living for 20 years. Great teacher, though.

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I had a hard time with the first batch, but I added a bit extra water and it worked fine. Do not forget to wet the blocks though, they soak up the water right away.