I'm not familiar with that acrylic mortar product, but you should generally be careful about repairing brickwork with anything but ordinary mortar. Mortar spalls off because of hydrostatic pressure due to water wicking up from the ground, not from rain water. The brick doesn't spall because it is stronger than the mortar, and the spalling mortar relieves the pressure on the brick. If you replace the mortar with anything stronger than the brick, the brick will spall, and that repair will be costly.

There are so many reasons why this is just wrong. Caulk is not a good thing for filling joints in masonry. This is just sanded caulk, a water based no less. It will deteriorate in short order, shrink away from the bricks & allow water to flow in. The price, $4.00 for 10 oz, compares to a bag of mortar @ $4.00 to make about 3 gallons of mud.
I can see nothing good or useful about this product.

For a repair of the size shown in the photo the acrylic is certainly better than nothing and almost certainly will not lead to damage. Here in New England, where I do a lot of work on houses, freezing can be a problem for brickwork. Specifically, water getting into the sort of cracks and holes shown, then freezing. Each freeze-thaw cycle makes the problem worse. Ideally you'd use mortar which, as William noted, can be a PITA on such a small job. Short of that, he did good by fixing it the expedient way rather than letting it go unattended.

Just a small nit-pick, not meant to detract from the possible value of this product.

"Tuck-pointing" is a rarely used technique that Victorian-era Noveau Riche and others used to make old, hand-formed brick buildings appear to be newer buildings of cut brick. You chisel out the old mortar, and point with mortar that is color-matched to the brick, then lay in a thin line of pipe clay or pure white mortar in the exact center of the colored mortar. This makes the mortar joints appear thinner, which is the whole and entire point of tuck-pointing. NOBODY does this anymore. You have never met and will never meet a tuckpointer, it is a historical technique useful for dating buildings.

What you're talking about here is simply "pointing", that is, replacing mortar.

Brickwork that is properly constructed will need to be re-pointed every century or two; badly made brickwork more often. Always use a softer mortar than the brick; the older your brick the softer it is, so be careful!

Here's the secret to mortar grades: M-A-S-O-N-W-O-R-K use every other letter. Type K mortar is unuseably soft, it's nearly sand. Type M mortar is so hard it should never be used for anything built prior to the 22nd century. Use type N for nearly all jobs, use type S for stonework because it has a bit of lime in it which makes it sticky. S=Sticky=for Stonework, N=Normal=non-brick-shattering.

Thanks for the tip on Quikcrete sanded caulk - nice to know about for filling small voids in masonry!

Just another vote of confidence for this product on small repair jobs. Our house has brick stairs and also some brick trim. A few years ago, we had to do some serious mortar repair on the stairs, used real mortar for that. Later, we noticed some little bits missing on the trim. Still remembering the stair project (not fondly, mind you), neither my husband or I wanted to tackle the repair. We were positively giddy that the quickcrete had worked so easily, and has held up so well.

PS. Thanks for the tuck pointing explanation. Lots of houses in the northeast have it and I've always thought it was curious. Now I know!

I've a bit of experience in dealing with masonry in my work & have done research & repairs on brick, block & stonework built in the last 10 years to well over 100 years. This link seems to layout mortar types & uses quite nicely.

http://www.mc2-ice.com/support/estref/popular_conversion_files/masonry/mortar.htm

I stand by my slagging of this product as completely inappropriate for pointing masonry. It won't stay adhered to the masonry & will quite soon allow water in. Before it does that, however, it will, as mentioned in previous posts, prevent water vapor in the wall from exiting via the mortar joints, thereby potentially damaging the bricks, stone or other masonry. Even the mortar I recommended should be used only on modern bricks or block. If I've got to use it for old, soft brick or stone I add lime & sand to soften it up.
Additionally, cleaning caulk off of brick & stone to do the job right is a hellacious pain in the butt. A product such as this will not do a very good job to solve the problem it purports to remedy, & will create more work to be able to do the job properly at a later date.
Peace
JJS

As an architect involved with historic renovations and the owner of a similarly aged masonry house I must tell you not to use this product or any other mortar without further investigation.

Old brick is often not fired to the same temperatures we fire brick to today. This means the brick is soft often only the surface is hard making the brick analogus to bread. Because the brick is soft it expands and contracts differently and the mortar needs to be soft so that it can move as well. Using a hard mortar will cause the brick to fail via thru body cracks or with face spalling which exposes the soft interior to the weather. The photos suggest this wall has had several bad pointing repairs and bad tuckpointing or as it is correctly called: repointing.

If you use the products you can destroy the brick and create a whole host of other much more expensive problems.

My recommendation is to speak to masons in the area with experience repairing old work and learn what sands and mortars were locally used when the house was built and how they were mixed. Consider repointing entire faces at one time to maintain a consistent appearance. You will do much more to add to the life of your buidling this way.

Some times the old ways are the best ways.