02 May 2013

When is a queen not a queen?

When is a queen not a queen? When she's a brick.

Worcester Guildhallfigure of Queen Anne
(ell brown on Flickr)
Several years ago, I got into a discussion with an architect about the size of brick he wanted for a project. He said he wanted modular brick; I asked for a specific size, and he simply repeated modular. I knew it wasn't quite that simple, so to prove the point, I compiled a list of brick names and sizes I got from several brick companies.

Although I knew there would be differences, I was surprised how many there were (see the list below - and that's not all). Now, some might argue that the differences aren't all that important; after all, the three lengths of Norman brick - 11-7/16, 11-1/2, and 11-5/8 inches - are all considered nominal 12-inch. Similarly, 3-1/2 and 3-5/8 inches would be considered nominal 4-inch.

However, looking at it from another perspective, the three nominal 12-inch lengths give mortar widths of 9/16, 1/2, and 3/8 inch - the widest being 50 percent larger than the smallest. Depending on the mortar color, the appearance could be quite different.

Courtesy Brick Institute of America
To further confuse the issue, we often talk about modular dimensions, which, in general terms, means units of something that have joints at multiples of a given dimension, say 24 inches. For modular brick, a combination of bricks plus the same number of mortar joints, give dimensions that are multiples of 4 inches. So, what you might consider a modular brick size in this sense might have a name other than modular.

The appearance of a brick wall depends not only on the size of the brick, but how they are put together, or bonded. Structural bonds are used to interlock brick units, while pattern bond refers to the appearance of the exposed surface. With brick veneer, we're concerned only with the visual pattern.

Bond patterns suffer the same problem that affects brick sizes; they also have various names that are not consistent. You might think that running bond is a universal term, meaning brick courses that lap each other by half a unit, but it's not. Another term used for this pattern is stretcher bond, and running bond itself comes in at least two flavors - 1/2 running bond and 1/3 running bond. Although it is possible to lap brick at any dimension, laps that are multiples of the brick width are most efficient and attractive, as they don't end up with odd pieces at the corners.

Longer brick provide more options for bond patterns. A 1/2 running bond is similar in appearance to that of 8-inch brick, though the head joints are obviously farther apart. If each successive course is offset four inches from the one below in the same direction, a stair-like effect appears. If the courses are offset four inches in alternating directions, pairs of vertically aligned joints appear. All visual effects are emphasized by high contrast between the mortar and brick colors.
A good looking bond pattern, but not what was expected.
A good looking bond pattern, but not what was expected.
Use more than one size of brick, more than one color, or brick from more than one manufacturer, and the number of combinations becomes enormous.The bottom line is, when you specify brick, give the specified dimensions, and, unless you're using stack bond, show the pattern in a detail. If you rely on just a name for the brick size or the bond pattern, you may be surprised by the results!

Gregg Borchelt, President and CEO of the Brick Industry Association (BIA), adds, "Actual dimensions are just that, and are not known until the brick is delivered. Specified dimensions have tolerances in the ASTM standard for that unit, and the combination of specified dimensions and tolerances give a range for actual dimensions."

Refer to BIA Technical Notes 30 - Bonds and Patterns in Brickwork for more information. Whenever you're working with brick, it's best to refer to BIA Technical Notes

Width Height Length Manufacturer's names
2-3/4 2-5/8 8-5/8 Builders Special
2-3/4 2-3/4 7-5/8 Queen HSP
2-13/16 2-5/8 9-5/8 King
2-13/16 2-13/16 7-5/8 Queen
2-13/16 2-13/16 8-5/8 Queen DVP
3 2-5/8 7-5/8 Queen
3 2-5/8 9-5/8 King, Economy Modular
3 2-5/8 11-5/8 Norwegian
3 2-3/4 9-1/2 King
3 2-3/4 9-5/8 Engineer King, King
3 2-13/16 7-5/8 Scotty
3 2-13/16 9-5/8 Engineer King
3 2-7/8 8-3/4 Colonial
3 2-13/16 11-5/8 Super Scotty
3 3-5/8 11-5/8 Saxon, 3-Inch Utility, 3" Bed Economy Norman
3-1/8 2-3/4 7-5/8 Slim Jumbo Modular
3-1/8 2-3/4 9-5/8 Queen
3-1/2 1-5/8 11-1/2 Roman
3-1/2 1-5/8 11-5/8 Roman
3-1/2 2-1/4 7-5/8 Modular
3-1/2 2-1/4 8 Standard
3-1/2 2-1/4 11-7/16 Norman
3-1/2 2-1/4 11-1/2 Norman
3-1/2 2-1/4 11-5/8 Norman
3-1/2 2-11/16 11-1/2 Norwegian
3-1/2 2-3/4 11-5/8 Norwegian
3-1/2 2-13/16 7-5/8 Engineer
3-1/2 3-1/2 7-1/2 Titan, Continental/Closure
3-1/2 3-1/2 11-7/16 Norman Titan, 100 Saxon/Utility 4"
3-1/2 3-1/2 11-1/2 Norman Titan, 100 Saxon/Utility 4"
3-1/2 3-1/2 15-1/2 100 Giant 4"
3-1/2 3-5/8 7-5/8 3-Inch Utility
3-5/8 2-1/4 7-5/8 Modular, Standard Modular
3-5/8 2-1/4 8 Standard
3-5/8 2-1/4 11-5/8 Norman
3-5/8 2-1/4 15-5/8 Ambassador
3-5/8 2-5/8 7-5/8 Engineer, Engineer Modular, English, Oversize, Full Bed Depth Queen, Danish Hand Mould
3-5/8 2-5/8 9-5/8 Full Bed King
3-5/8 2-3/4 7-5/8 Engineer, Engineer Modular, English, Oversize, Oversize Modular, Full Bed Depth Queen
3-5/8 2-3/4 8 Jumbo
3-5/8 2-3/4 11-5/8 Jumbo Norman
3-5/8 2-13/16 7-5/8 Engineer, Engineer Modular
3-5/8 2-13/16 11-5/8 Engineer Norman, Norwegian
3-5/8 3-5/8 7-5/8 Economy Modular, Closure, Econo, Modular Economo
3-5/8 3-5/8 11-1/2 Economy, Jumbo Utility, Saxon, Utility
3-5/8 3-5/8 11-5/8 Economy, Economy Norman, Utility, Jumbo Utility, Saxon, Giant Norman, Monarch
3-5/8 3-5/8 15-5/8 100 Giant 4", Meridian, Monarch
3-5/8 7-5/8 7-5/8 Triple Brick
4 2-3/8 8-3/8 Ontario

4 comments:

  1. Check out the UK standards for how to build in bricks. That's where the real experts live!

    ReplyDelete
  2. I'm sure the Brick Industry Association would argue the point! :)

    Do you have links for specific standards or organizations?

    ReplyDelete
  3. You left out my favorite brick coursing variable: stretcher, header, rowlock, soldier, sailor, shiner.

    ReplyDelete
  4. Sounds like a nursery rhyme.

    Stretcher, header, rowlock;
    Soldier, sailor, shiner.
    Using just the right ones;
    Will make your brickwork finer.

    ReplyDelete