Like music lovers everywhere, residents of West Vancouver were well acquainted with the seminal Joni Mitchell song, Big Yellow Taxi, and its naturalist sentiment: They paved paradise and put up a parking lot. In 2015, these residents were pitched on a condominium development, Sewell’s Landing, on the banks of Horseshoe Bay.
Architect Paul Merrick’s ambitious and thorough plans turned Mitchell’s song on its head by ripping out the existing marina’s tarmac parking lot and leaving the natural beauty of the surrounding wooded hillside intact.
The plans were modelled on a traditional Italian seaside villa and included terraced residential units, along with cobblestone roads and walkways.
West Vancouver residents were promised the development would meet their expectations through sustainable design and eco-friendly solutions, and a unique mix of uses that promote active modes of transportation.
“Landscape and groundscape will be treated essentially like a European village, with cobbled or textured stone in the piazza (and) irregular stone paving in larger pieces on the pathways,” Merrick wrote in his proposal. “The development will provide adequate underground parking for Sewell’s Marina, as well as all residential and supplementary commercial uses. Vehicle access to parking will be discretely managed through site terraces, and pedestrianized plazas through small portals into underground parking.”
Mapei on the Job
Finding the right setting products for such a unique application of the cobblestones and granite paving stones posed a challenge. It was a problem Dave Randall, Mapei business development manager for Western Canada, was brought in by Merrick Architecture to help solve.
Over the next seven years, Randall served as Mapei coordinator on the project. He assisted in the installation of cobblestones and granite paving stones over a 36,000-square-foot area to meet the stringent specifications that are usually reserved for concrete or tarmac roads.
“To use paving stones as roads, they had to show it would have a 28-day compressive strength of 8,702 psi for emergency vehicles — basically, for a 35,000-pound fire engine,” says Randall.
In North America, paving stones are not generally used for roads in this way. Randall knew the setting products required to meet that spec — and stand up to de-icing salts, seawater and freeze/thaw cycles — would not be easily found.
“I had to do some research,” he says.
Looking to Mapei’s existing tile and stone installations systems product line for North America, Randall found nothing that fit all the criteria that was needed.
“Other mortars on the market might have the resilience for salt water and freeze/thaw, but not the strength,” he says.
Mapei S.p.A. to the Rescue
Mapei technical services helped bring the mortars Mapestone TFB 60 and Mapestone PFS 2 from Mapei S.p.A. in Italy. These two products form the Mapestone system, which is a pre-blended screed mortar and grouting solution for architectural stone flooring that features high compressive strength and good resistance to freeze/thaw cycles, de-icing salts and seawater.
“I proposed it to Merrick and the other stakeholders at the time and that got this put into the spec,” says Randall. “Different landscapers came up with other ideas but nothing else met that spec, so we got on our horse and started the process in 2017 to bring the formula from Italy.”
Initial batches of Mapestone TFB 60 and Mapestone PFS 2 went through testing and trial runs in Mapei’s plant laboratory in nearby Delta, B.C.
“Then we did field trials and some mock-ups and got to put it into place in other local projects to get a good idea of how it performed,” says Randall. “We did some training in the T. Moscone & Brothers’ yard in early 2020. It was a lengthy process.”
Eventually, work got underway on the actual stone installation in 2021.
The stones themselves were back-buttered with Granirapid System premium, rapid-setting mortar before placement. Designed to not contribute to efflorescence, the mortar allows for installation in both cold and warm temperatures. Additionally, Granirapid System’s early mechanical strength and rapid-setting qualities are helpful in dealing with sloped areas.
With the stones prepared, the team applied Mapestone TFB 60 to the bed where the stones were then set. Mapestone PFS 2 was then applied for grouting. Planigrout 755 construction grout was also used to secure linear drains for precipitation run-off.
In 2022, Sewell’s Landing was fully delivered as advertised, with its durable and beautiful cobblestones covering the spaces in and around the new village and spruced up marina.
A gentle warning to diehard Joni Mitchell fans: With Mapei products, they literally built paradise over a parking lot.
Jonathan Clavet is director of technical services at Mapei Canada, based in Laval, Que. He has been in the construction industry for more than 20 years, receiving his bachelor of engineering in construction in 2012, from l’École de technologie supérieure in Montreal.