World's largest modern wooden building
A method of layering wood with glue solves many of the problems with building with wood, providing a light, low carbon option. Ewen Kellar told Chris Smith more about a new project using this innovative material.
Ewen - This is a building project in Hackney in London. It's the Dalston Lane Development which is really a wonderful example of taking an old material wood and using it in a new way to build - they reckon to be one of the largest of its type, building construction projects certainly in the country. They're going to use more than 3,5000 cubic meters of wood, which is quite a lot actually, and the type of wood is, it's a sort of a laminated sort, a little bit like plywood. But rather than just lots and lots of thin layers, what you have here, you've strips of wood which are aligned at right angles to one another and all bonded together using an adhesive and a big press.
Chris - That gives you enormous strength, doesn't it? Because wood is strong in one direction but weak in another. So, by putting them at 90 degrees to each other, you're effectively sharing the benefits of both directions.
Ewen - Yeah, absolutely and you're also addressing things like the fact that wood, in its natural state, of course, starts to shrink in different ways and twist and bend. So, if you artificially bond it together, you can make flat boards stay flat for a long time.
Chris - So, you won't get a bent building.
Ewen - That's the hope.
Chris - When is the building going to be finished by?
Ewen - I think it's just started now. So, pretty soon I think, in a year or so time, but the key thing here is, why they're using this approach is that one, to tick a green box because obviously, using timber is a very green way of capturing carbon dioxide as opposed to using concrete which is, you need to produce a lot of carbon dioxide when you're making concrete. So, it's actually a really environmentally, unfriendly material as far as that's concerned. So, it's addressing that but it's all because wood is a darn sight lighter than concrete. This development is actually going all the way over a whole lot of holes under the ground, the tube cross rail, etc. so, they actually need lightweight buildings to actually be built in this. Otherwise, there may well be a little bit of a collapse of the buildings into the ground.
Chris - Will it last as long as concrete would?
Ewen - Well, probably longer actually if it's treated properly. I mean, concrete from my memory basically, which has a peak strength of about 20, 25 years, and then it actually starts to deteriorate over time especially if you've got steel reinforcing material in it which actually can start to rust and start to cause cracking. It doesn't happen with every concrete building, but it certainly can.