Design Museum Pavilion · cladding & foundations

Since getting the timber order in with Pollmeier, who are kindly donating some of their beautiful beech LVL ‘Baubuche’ beams, I’ve been working with Pete, Hattie & Max on the design of the metal connections and foundations. The two props at the front and back of the structure are being anchored into the flower beds with helical anchors, kindly being donated by Spirafix. After a site visit to dig some trial holes, we put the order in for two 40mm C Type anchors, which will be hammered into the ground to a depth of 500mm. On either side of the structure, we will need mass concrete blocks to prevent overturning, and also stop the structure from splaying out. These need to be 0.3 cubic meters, and we’re very grateful to Blu-3 (the contractors responsible for all the landscaping around the site) who are going to cast these next week! The design was originally a curved shape, following the back edge of the existing benches, and has since developed into a chevron, with the steel plate for the footings sitting flush against the front edge. There’s some concern that this doesn’t allow for much tolerance, so I’m meeting Blu-3 next week to talk the process through.

After a couple of weeks developing & discussing the metal connections, we decided to use 6mm aluminium throughout, with pre-cut holes so that we can tack them into place – with the view to drilling all the other holes on site (which would be tricky if we were using stainless steel which is a much harder metal). We’ve developed a flag shape for the hangers, which can be used for each of the ribs despite the different angles – although I kind of liked the idea of 11 bespoke hangers, having a universal one is obviously much more efficient to make and will also be less confusing on site. Cut Tec have very generously agreed to last cut all the pieces of metal, and will send them down to Fish Fabrications to be welded next week (who again – incredibly kindly – are doing the job pro-bono). The crucial missing links at the moment are transportation of the timber from Germany to London at the end of this month, and treatment for the timber…

For the cladding, we’re developing a system of fibreglass shingles, using a 2mm sheet material being donated by Filon – which has enough rigidity to not deflect between the ribs, but enough flexibility to accomodate the curvature between each rib. It’s actually pretty hard to work out, as the structure is deceptively complicated – a simple idea but quite a complex geometry. Not only is each rib a different length, but none of them are actually parallel… although they seem to be in plan, the fact that they are at different angles means that they get closer together towards the middle of each rib. The choice is between using many bespoke shingles (time consuming to manufacture and keep track of on site), or a uniform size which overlaps to varying extents across the surface of the structure – leading to questions of opacity and levels of light transmission. Filon have been great about promptly sending samples of all shapes and sizes, and we’re hoping to get a system resolved in the next week.