The Move to Pre-Blended Mortar - Pro Masonry Guide
Pre-Blended Mortar

The Move to Pre-Blended Mortar

Big sand piles are necessary for mixing traditional mortar

Less labor, more choices: The growing dominance of pre-blended mortar is changing the mason’s business model.

By Jim Cook

Images courtesy of Spec Mix

When Jim Doane began work as a mason, big sand piles necessary for mixing traditional mortar were a given on just about any jobsite. Today, Doane sees fewer of those sand piles as pre-blended mortar increasingly dominates the industry.

“Until last year, my local brick yard was still selling masonry sand and cement,” says Doane, a South Florida mason contractor. “Now all they sell are pre-blended mortars. Home improvement stores are now stocking a larger variety of specialty pre-blended mortars, like water-repellent mortars, stone veneer mortars, and stucco mortars, in addition to type M and S pre-blended mortars. This greater market availability was not present in the masonry industry 10 years ago.”

Innovations and improvements to pre-blended mortar and its delivery systems in the last decade have changed the business model for many masons. These changes have resulted in an ability to more accurately bid projects, reduce labor costs, improve product quality, and reduce waste and environmental impact.

“Labor and material costs have declined greatly,” Doane says. “Just one example is not having a sand pile on the jobsite to make mortar. Storage of sand is always an issue on tight jobsites and for interior work. What should you do with any leftover sand? Do you discard it? Try to transport it to the next jobsite? These costly issues with a sand pile on the site are now eliminated.”

Spec Mix introduced a silo system in the late-1980s that made storing, mixing and delivering pre-blended mortar to masons less labor intensive and time consuming. This created a critical advantage over the traditional field mix.

“Pre-blended construction materials have been around since the 1940s, but we’re the ones who came to the market with an efficient, safe, material delivery system,” says Brian Carney, Spec Mix vice president. “It took away the lifting and shoveling of field-mixed products. It made the whole process up to 40 or 50 percent more efficient.”

The business case for pre-blended masonry

Carney says the company continues to lead the way in innovation, making strides in developing more portable silo systems that make getting mortar to masons even quicker. This has reduced labor costs for mason contractors.

“Now, contractors have the ability to mix materials very close to where their masons are working, instead of mixing a football field away, which eats into forklift time, availability and fuel expense,” says Nick Blohowiak, Spec Mix national masonry products sales manager, “not to mention the cost of masons sitting idle on the wall waiting on mortar.”

Pre-Blended Mortar

Blohowiak says interior work is where pre-blended materials help make contractors highly productive. Using pallets of 80-pound bags or the Spec Mix PA1000 system with bulk bags allows the contractor’s mixing station to move quickly from floor-to-floor, without waste or the use of crane time, Blohowiak adds. The contractor can basically mix wherever and whenever he wants, rather than at street level. The long wait on materials is eliminated as well.

“Masonry foremen used to have laborers show up 30 to 45 minutes early each morning to mix the mortar needed for 20 to 25 masons,” Carney says. “Now, the laborer can show up 15 minutes in advance and get six tubs of mud out right away. It may seem insignificant, but over time, the efficiency adds up to real dollars.”

Carney says that, in addition to the productivity factor of a more portable product, pre-blended mortar makes masonry more accurate and efficient in materials usage. Pre-blended mortar bags and silos leave little or no waste of material, and estimators have a more accurate idea of how much material they need to complete a project, he adds.

“Estimating has gotten really tight, and now a project estimator can confidently calculate how many block or brick the masons will install per bag of pre-blended mortar,” Carney says. “So, whether it’s material or labor requirements, pre-blended products have changed the formulas contractors used to bid masonry projects.”

Other benefits to pre-blended mortar

Pre-blended mortar also eliminates sand bulking, a problem that arises when sand mixed with mortar in field mix is contaminated, according to Cory Olson, vice president of Amerimix, another producer of pre-blended mortar.

“For example, if soluble salts end up in the mortar, that could cause problems for reinforcing steel that is subject to corrosion from them,” Olson says. “Other contaminants could cause chemical imbalances in the mortar such that problems show up later, like efflorescence on the face of the finished masonry. Any deficiency in the wall that can be traced back to the mortar is a ding on the mason’s reputation and can mean repair work – a major blow to profits, since crews are repairing versus generating new revenue.”

Pre-blended mortar does not pose the same problems that field mix does when temperatures drop, thanks to the way it is made and stored. This is a key logistical benefit of its use in the northern United States.

“In the North, damp masonry sand will freeze during the winter and must be heated significantly, causing additional cost and inefficiency,” Blohowiak says. “A frozen pile of sand kills jobsite productivity. Today’s mason contractors have realized silos and pre-blended mortar and grout are the solution for profitable, cold-weather masonry construction. It’s the reason you almost never see a commercial project without pre-blended products and silo systems; warm water is all that’s needed.”

Color mix and match

Making pre-blended mortar in a factory, rather than in the field, also has led to the development of improved colored mortar and mortar blends that work well with specific masonry units, such as various types of brick or natural stone materials. In factory conditions, manufacturers can better control the components going into the mortar, whereas with a traditional sand pile and bagged goods, it’s all guesswork with some sand and a shovel.

Olson is seeing a lot of innovative solutions for colored mortar. Amerimix maintains a color technology lab where spectrometers are used to precision-measure color for exact matches, based on customer preferences. Much like paint centers found in big box retailers, Amerimix can get within a nominal percentage of a given color through its lab process.

Spec Mix engineers are developing high-performance mortar formulations with properties featuring water repellency, increased bond strengths, reduced set times for hot weather construction, and accelerated setting for cold temperatures.

“For example, with clay brick, there’s a range of properties it can exhibit on the jobsite, from hard brick that doesn’t absorb water to soft brick that takes on water like a sponge, and everything in between,” Blohowiak says. “I can actually design mortars that work with the characteristics of brick. If the brick wants to pull a lot of water, I can create a mortar that uses a lot of water and allows for water absorption.”

With clay brick, there’s a range of properties it can exhibit on the jobsite

From the mouths of masons 

Atlanta mason contractor Dave Jollay uses pre-blended mortar for gray mortar about 60 percent of the time, for colored mortar about 15 percent to 20 percent of the time, and for grout, about 85 percent to 90 percent of the time. Jollay says there is still a place for traditional mortar mix on many jobsites.

Cost and quality guide Jollay in making decisions regarding using pre-blended mortar versus a field mix. He says that, while pre-blended mortar does reduce a masonry operation’s footprint on a jobsite, it can be impractical for floor-to-floor work, due to the size and weight of silos and equipment needed to mix the mortar. Jollay says that while smaller 80-pound bags of mortar can be taken up on higher floors and prepared there, moving these bags still poses an injury risk to workers. He adds that buying 80-pound bags also is more expensive than purchasing the larger bags used in silos.

Jollay would like to see pre-blended mortar makers continue their work in making their delivery systems more portable. He also remains more comfortable with mixing his own colored mortar on site, as he feels it gives him greater control over color consistency in projects. Architects who work with Jollay’s company typically specify the mortar suppliers and manufacturers they wish to use, he says.

We spend a lot of time with our architects on color selection.

“We spend a lot of time with our architects on color selection and they don’t want any variation on color,” Jollay adds.
Doane has a different take. He specializes in custom masonry, including historical restoration projects, and says that even on historical projects, pre-blended mortars are the best solution.

“I do not use any traditional blended mortars at all,” Doane says. “For me, pre-blended mortar is superior. Even in historical masonry work, there are pre-blended natural cement products, lime putty, Portland cement lime mortars, etc. that are manufactured.”

Blohowiak estimates that in the Unites States, about 70 percent to 80 percent of commercial jobs use pre-blended mortar, while many residential masonry markets are still using field mix. He adds that as a new generation of masons who have trained primarily on pre-blended mortar cycle into the industry, the trend toward exclusive use of pre-blended mortar will accelerate.

Jim Cook is a freelance writer based in Dothan, Ala. He can be reached at

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