Let's bring back tasty waffle slabs
In the Washington Post, they write about How pancakes and waffles divide the nation. I have always preferred waffles to pancakes, which I consider to be limp and formless. Waffles, on the other hand, have form and real substance, structure and rigidity.
It is much the same in architecture. A concrete slab is- just a slab, and a thick one at that, using a lot of concrete to get to the depth it needs to span a significant distance without limply sagging. You don't look at it because it is boring, and the electrical or mechanical services are hanging from it so they are covered with even more boring drywall.
Lloyd Alter/ Montreal Museum of Fine Arts/CC BY 2.0
Waffle slabs are different. They are designed to be thick where you need it, for the structure in the ribs, and thin for the slab. They are designed to be exposed and seen and enjoyed. Today I was walking through the wonderful Montreal Museum of Fine Arts' decorative art collection in the Liliane and David M. Stewart Pavilion and had trouble looking at the fabulous stuff because I was entranced by the ceiling, layers of the tastiest waffle slabs I had ever seen. The entire structure is there for you to see: nothing but the concrete that it holding itself up.
© Engineering Heritage Australia
Almost nobody really does waffle slabs anymore; they can be expensive, with the reinforcing carefully placed in narrow ribs between forms.
© John B. Parkin
They can be really hard to repair; one of the reasons that Toronto's iconic John Parkin Terminal was demolished was because he built the parking garage with waffle slabs, and one should not put salt on waffles.
But while we are no fan of concrete on TreeHugger, there are good things to say about waffle slabs. They use less concrete, and they look good enough to leave exposed so you use less of everything else.
Lloyd Alter/ National Theatre/CC BY 2.0
There are wonderful waffles at the National Theatre in Britain;
Lloyd Alter/ Confederation Centre/CC BY 2.0
And really cool ones at the Confederation Centre in Charlottetown, Prince Edward Island, where in one section, they even left off the slab itself and put on great pyramidal skylights.
Holedeck has figured out a great way to integrate services into them. Perhaps it is time to say that if we have to use concrete in our buildings, then we should let concrete be concrete, exposed and beautiful through thick and thin. It's time to bring back tasty waffle slabs. Mmmmm.