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Masonry myths.


Thomas Brumfield (right) has seen it all. After more than 20 years as a journeyman mason working in six states, he knows what's behind the brick veneer of most masonry jobs, and he wants you to know about it. "Builders and should be aware that what they want isn't always what they get when it comes to masonry work," he says.

"These aren't masonry's dirty little secrets," says Brumfield, now a job-site super for QuickSilver Construction in Lubbock, Texas. "It's just that no one has ever told contractors and architects what really goes on during a job."

MYTH #1: Masons Have No Opinions

It used to be that builders and architects never asked a mason for any advice. "That was just the chain of command," Brumfield says.

No longer: As masons change (more open shops, more versatile skills), some barriers are finally coming down. "Suggestions from our subcontractors are welcome if it means we'll end up doing it right," says Larry Trammell of Total Design Three, a design-build firm in McCall, Idaho. "I'm no mason, so I rely on their expertise. There may be easier ways to do things that we just don't see on the plans."

To encourage input from masons (or any subcontractor), builders should make provisions in the bid documents for alternative specs and suggestions. "A smart contractor won't bid plans with a lot of problems," says Michael Adelizzi, executive director of the Masonry Contractors Association of America, which represents 1,000 firms nationwide. "After the contract is awarded, it's hard to make changes to the specifications without adding costs and change orders."

MYTH #2: Weep Holes Work Weep holes in masonry walls look good on paper but often get buried - literally - when masons build the walls and try to leave a cavity. The problem: Excess mortar from the bricks can drip down into the air (or finger) space between two walls, clogging weep holes installed at the base of the wall and perhaps creating thermal and moisture bridges from the brick to the interior wall surface [ILLUSTRATION FOR SKETCH 2A OMITTED].

Brumfield says design is part of the problem. "If masons aren't given at least an inch of finger space, we have a hard time drawing [excess] mortar away from the back of the wall," he says. (In practice, Brumfield adds, the 1-inch gap also allows the brick facade to mask any juts, bows, or other flaws on the inside wall.) What's more, he says, "Younger masons rarely leave full head joints when laying brick," which creates entryways for water and increases the likelihood of damage.

A simple solution: Make sure the foundation base accommodates the combined dimensions of the CMU (concrete masonry unit) wall, insulation panel (if any), adequate air space, and brick facade. A good mason will furrow the mortar or bevel the brick mortar bed away from the air space to reduce the potential for drips.

Brumfield recommends demanding full head joints and eliminating the fancy weep hole designs; instead, allow the bricklayer to leave out head joints entirely every 2 feet or so to act as the wall's drainage system [ILLUSTRATION FOR SKETCH 2B OMITTED]. "If the inside wall and the remainder of the head joints are tight, they'll keep moisture and bugs out well enough," he says.

MYTH #3: Masons Love Pre-Insulate Block

"Masons carry blocks two at a time, one in each hand," Brumfield says. "Foam inserts make it impossible to get your fingers in the web" [ILLUSTRATION FOR SKETCH 3A OMITTED]. Because masons work in such a time-sensitive trade, few appreciate the benefit of insulated CMUs because they're harder to handle and to lay in place.

And, says Brumfield, masons are so production-minded that, should an insert fall or get knocked out during wall construction (to accommodate plumbing runs, for instance), they probably won't put it back in.

According to the National Concrete Masonry Association (NCMA), which represents block manufacturers, insulated CMUs ensure architects and engineers an insulated structure without having to design for panel insulation or other thermal protection. "We haven't heard too many complaints," says Kevin Callahan, an NCMA technical consultant. "CMUs are popular with architects, despite the fact that they may be more difficult to lay."

"Manufacturers never pick up the block by hand," says John Pies, executive director of the Expanded Shale, Clay and Slate Institute, which supplies lightweight aggregates to block makers. "They have no reference or respect for how the material handles."

What builders can do: Specify pre-insulated block with foam panels in the center, not the side [ILLUSTRATION FOR SKETCH 3B OMITTED], or consider rigid foam panels on the outside of the wall.

MYTH #4: Welded Wire Works

Before Hurricane Andrew ripped through South Florida a few years ago, only masons working on expensive high-rise buildings used welded wire mesh for lateral support of a masonry wall [ILLUSTRATION FOR SKETCH 4A OMITTED]. Now, says Miami builder Eduardo Camet, codes and building officials insist everyone put it in. "People at the county say it adds reinforcement," Camet says. "Is it going to make a difference in the next hurricane? I doubt it. The experts also say it reduces cracking, but it's hard to believe it's better than filling every fourth block with a #5 rebar and concrete, especially with a bond beam on top" [ILLUSTRATION FOR SKETCH 4B OMITTED].

Brumfield says he and his fellow masons hate welded wire almost as much as pre-insulated blocks. "It gets all cut up anyway for mechanical runs," he says. "And if it gets bent, it's impossible to lay your block to the string line," in which case the section of wire either gets cut out - rendering the remaining wire useless - or the finished wall juts out around it. If wire is in the specs, he says, use a lighter gauge that's easier to handle and bend in place. Or consider an alternative, like bond beams.

MYTH #5: A Block is a Block

"It's funny that bricklayers can moan about handling welded wire and still be able to feel a 1/16-inch difference between modular bricks," Brumfield says. "You can take the top row of a standard hundred pack [of bricks] and only seven will be the same size."

While terms like "modular" and "standard" would seem to ensure uniform dimensions for bricks and blocks, the reality is that masonry units aren't created equal - affecting both installation and the finished building's aesthetic. "When you're trying to hold an exact head joint, that kind of [a 1/16th of an inch] variation can add up to a 1/2-inch difference along a five-brick run," Brumfield says.

Standards for brick and block dimensions - inside and out - are set by the American Society for Testing & Materials. The standards allow manufacturers to vary dimensions 1/8 inch from what they specify to masons and designers; nonmodular brick sizes, in fact, can vary 1/4 inch from a manufacturer's specs.

MYTH #6: A Mason Is a Mason

While Brumfield believes masons should simply install bricks and blocks and not much else on a building project, others see a shift. "We'll build the whole house, if possible," says Chuck Nacos of Soderberg Masonry in Fort Collins, Colo. "I'd rather not give away work and make the owner manage more trades."

On a recent project, for instance, Nacos' firm contracted to install a steel beam because the owners didn't want the hassle (and expense) of hiring an ironworker for such a small job. The same goes for waterproofing, installing foam panel insulation, and light welding.

MYTH #7: Builders Know Masonry

Think you're up on the mason's lingo? Okay, maybe you do understand the easy ones like bond beam, vertical pour, and CMU. But to really test your knowledge, see page 151.

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Title Annotation:housing construction and masonry
Author:Binsacca, Rich
Date:Sep 1, 1996
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