sweat the details…masonry
7 December 2011
Details details details. This is the mantra of the architect. This is the destiny of the architect. We sweat the details most other people never notice. It is often the case that most people do not notice when we get it right, but they notice if we get it wrong. No credit for good effort is given it seems. However, not all architects get it right and certainly contractors overlook it as well. It seems it is actually harder to build something clean and simple than something that is full of trim and other measures added in order to cover the joints, flaws and intersections of sloppy or poor craftsmanship.
Recently I thought about this as I observed a few poor masonry installations. Either there was a bit of oversight with respect to coordinating various materials or the installation was not done with appropriate care. In each of these cases I am criticizing both the designer and builder. Then to balance the discussion, later I add a few detail images that I find to have been designed and executed well. Kudos goes to the designers and to the builders.
In this first photo we see that there is no coordination between the vertical masonry coursing and the window head location. The mason had to cut the bricks above the window to insert the steel lintel. This is supposed to occur in the coursing pattern to permit the lintel to bear on one course of masonry and be hidden within the mortar joint. Either the designer and/or contractor totally ignored this one or the brick coursing dimensions changed and no one thought to alter the window size to fit. It required the mason to stop the normal sequence, cut brick horizontally (and hope not to break them) and then install the lintel. This equals more time and money for a bad detail. The window could have easily been made a few inches taller to fit within the brick pattern. This one might be the most egregious of my illustrations today.
This next photo was taken, oddly enough, of the same building. A real winner you’re thinking. We see a brick rowlock course wrapping the building as a decorative feature. Directly beneath it, the mason cut the last row of brick horizontally so the water table could occur at a fixed dimension above the floor line. Did the designer intend for a different vertical brick coursing dimension? (i.e. 3 brick per 8″ versus 5 brick per 16″). Did the designer not even care? Was this detailed on a Friday afternoon before hunting season? Was it changed during construction by the contractor? Either way, this added expense lends nothing to the project and quite frankly detracts greatly as we see the brick course pattern broken with uneven brick slivers. The brick coursing could have been maintained with the water-table course occurring one brick higher or lower. I don’t recall seeing the water-table course aligning with any specific architectural feature or window sill either.
Here we see a clogged plastic weep tube. I presume the mason installing this did not ensure that these tubes remained unclogged. Perhaps I’m faulting the wrong party. I have found these familiar tubes to be difficult to maintain, so I specify another type. It’s good the weep tubes were included as an important part of the cavity wall system, but they do no good if they are clogged. The architect could have specified a more fail-safe component and the GC and mason need to pay attention to the details. I have also seen these tubes clogged by dirt and bugs. So who is to blame?
Although you can’t see it, I am guessing there is an asphaltic covered copper flashing or perhaps PVC flashing between the two types of masonry. Copper good…PVC bad. The flashing location is right on, but the type selected is all wrong. I have often seen the use of asphaltic coated copper flashing used where over time the sun heats up the wall and the asphalt melts and leeches out. This looks especially terrible over window heads (see next photo). There is a simple solution. I specify a copper flashing with a PVC scrim that serves the same purpose to bond the flashing to the mortar and masonry. I suppose the black asphalt can be cleaned and removed, but depending on the quantity used, it could be quite costly.
Ok, now let’s end with a few good examples. You may find fault in these, so have at it. However, I found these examples to be doing the right things based solely on what I could observe.
In this first photo notice a few things. We see two masonry types together. One is brick; a clay masonry. The other is concrete block. Brick and concrete expand and contract and differing rates thus there is an expansion joint that occurs vertically between the two. It is neatly caulked to allow for movement but match the mortar joint color. We also see that the brick coursing which is based on 3 bricks = 8″ aligns with the concrete block coursing that occurs every 8 inches. Alignment of masonry joints…good. If you look closely, the concrete block is dimensioned to remain on coursing; thus we see either a half block or a whole block. It is a neat running bond. The 4″ high smooth block at the window sill provides both a texture change and a shadow line at the stone window sill. Last we see that the soldier course occurring over the window head is based on an 8″ masonry module and it works out evenly within the course pattern. No cutting of bricks is always good. If you look carefully you can see the weep vents.
This next one shows an interest on the designer’s part to use the masonry coursing as a modern type of ornament, similar to the last image. We see a change in masonry texture from split face concrete block to smooth face block as a transition between the masonry foundation and the metal siding above. The block layout was carefully coordinated such that the smooth face block ends to align with the edge of the metal siding element above; all within a standard 8″ and 16″ block coursing. No cutting of blocks is always good. We also see a similar sill detail…a bonus.
These last series of photos are me being indulgent. The first is a house by the talented Ibarra Rosano which is a beautifully executed masonry house. Here we see in this photo how they respected the standard block coursing, but used a change of texture and color to highlight a ‘traditional’ lintel and sill, yet in a modern rendition. This is so simple, but so beautiful. The next photo is from the legendary Tod Williams and Billie Tsien Associates. They really have a wonderful knowledge of building materials and use the material properties and construction joinery as their own modern ornament. Here we see two materials turning a corner, yet there is great care taken to work within standard modules and achieve alignment of window heads. This doesn’t happen by accident. Someone must sweat the details. The last image is from Virginia architect, W.G. Clark. Here we see his wonderful ability to render the banal block into something amazing. He works within 4″ and 8″ modules creating a wonderful but minimal composition of block, concrete. metal and plywood. Truly inspirational.
Just as there is a time for everything under the sun, there is a time to celebrate great details and a time to mourn details gone badly. I hope we are all conscientious to design and/or build great details. Know thyself, know thine materials.
top photo from alisharama’s photostream on Flickr (used under the Creative Common License)
photo of Emma Willard School Hunter Science Building by Michael Moran for Tod Williams Billie Tsien Associates
the rest of the photos by yours truly…