DIY Sedum

A few years back when we were installing the huge sloping sedum roof at the International Digital Laboratory at the University of Warwick, I thought it was time to green the two modest flat roofs at home – 10 m² over the rear extension and 4m² over the ground floor loo.  The internet offered me two opportunities - a supplier in a garden centre in Kentish Town, who when I visited had stopped the previous week, and an on-line source that drove me so mad I gave up. 

International Digital Laboratory, University of Warwick

So imagine my delight when, in the recent post-holiday autumn lull, I found a whole host of sites offering DIY sedum.  Three days later a van from Q Lawns of Thetford arrived with 14m² of roofing and three hours after that it was laid – a separating layer of polythene, a springy lightweight drainage layer, a heavy felt and then the sedum itself more or less attached to another layer of felt.  The sedum came in 1200mm squares so I was grateful for my son Sol’s help carrying it up the stairs and laying it.

stacked in the hall

laying the felt

It’s not necessary but it should protect the asphalt from the sun and it does need the occasional weed but it is a delight to look out of the bedroom and landing windows at our DIY sedum.

Container Joy

17 years on the heaving waves, serving The Shipping Corporation of India, now transposed to a dune-side plot, ready for service for three, five, eight years? 

Pure volume of space, 8' wide, 8' high and 20' long, mute but resonant, endlessly adaptable yet utterly fixed.

Double doors at one end open wide to the world, a thick back wall of servant space. Within the bounding steel, no fixings, a temporary and contingent fitting out.

Secure, weather-tightness assured, perfect to store materials as found or as planned, to sort and rack, to prefabricate and transform into a new cabin.

In short, a sheddist's delight!

Making things last

Prevention, Reduce, Reuse, Recycle, Recover, and only a last resort Reject - the so-called waste hierarchy.

As we move towards the circular economy we need to stop using virgin materials and make mainstream the reuse of existing processed materials, whether by becoming more ingenious in how we reuse them, or thinking as we design about how their future reuse.

We are now taking part in a couple of TSB funded research projects exploring these themes.

In the REFab House project we are working with EcoBond Cymru, ASBP, C-Tech Innovation, and Bangor University to explore how houses might be designed to promote greater reuse of their materials.

The Steel Re-use project will look at the barriers and opportunities to use hot-rolled steel without recycling - recycling may sound worthy but it is hugely energy intensive compared with reuse. Leading that team is Julian Allwood whose book Sustainable materials with both eyes open is freely available online.

16 years ago when I built our kitchen I used a 40mm slab of maple, bought by the metre, to make a worktop, finished with three coats of Danish Oil.  It slowly scruffies out, so every three or four years on a dry day in the summer we take it outside, scrape it back to the bare wood, reoil it and bring it back to life.

At the rate of wear it should last well over a hundred years, and being loose fixed it can be passed to my grandchildren as a thing of beauty.

Durable doors

 I'd like to share an experiment in joinery detailing to keep maintenance to a minimum.

 Last summer's porch reconstruction just needed some doors to complete the work. 

There are three identical doors - two on the left to make a double door entrance, and a single one on the right leading to the woodstore. They're 2.35m high and 560mm wide.

The concept is a frame, rebated to take the glass, with a full width cover piece to the sides and top, and an aluminium 'sill' below. This drains the water away from the ventilated cladding to the lower part of the door. The 4mm toughened glass is dry glazed with a neoprene foam strip, squeezed in place.













The frame and cover pieces are made of  lengths of 120x27mm American Yellow Pine, beautifully straight-grained, hard and resinous. I cut the rebates and half lap joints on my radial arm saw, and glued up with exterior PVA without fixings. The inner frame is finished in Danish Oil and the cover pieces are left untreated. They are fixed with M6 stainless steel countersunk set screws, tapped into 5mm diameter holes. The lower cladding is untreated Douglas Fir, fixed to shallow battens over a breather membrane to created a rain screen cladding. Hinges are parliament hinges to get a solid fixing into the main frame. Handles are rescued samples.

I've waited a few months to see if moisture movement would be a problem with winding and binding but all seems surprisingly stable.  Goodbye putty and paint!

Arts and Crafts modern

Traditional natural building materials such as timber, cob, thatch had to be used in a way that recognised their limited durability. Steep roof pitches, generous overhangs result. If these rules were not followed they would have fallen apart quickly. Well detailed, they age gracefully and delight with their marks of age.

Fed up with constant repairs - in particular reputtying and painting timber windows at the beach shack - has made me think about how to detail contemporary building in a traditional way.

The existing porch was detailed to invite water into it, in particular a window sill sloping backwards. After twenty years it was oozing decay.

We rebuilt it in a week this summer using decay resistant but economical details. Sawn fence posts are directly glazed with 4mm sheets of toughened glass. I love that ambiguity of the frameless window - the magic of the invisible cloak. The sheets drain over a simple aluminium flashing over open jointed Douglas Fir cladding, all detailed to keep everything beyond the air barrier nice and well ventilated. The roof overhangs and protects the wall - no gutter needed here so we could make an exceptionally thin edge for a built up felt roof. This is a detail 'under test', taking advantage of a self-adhesive felt system where a simple aluminium angle is primed, making the felt stick tenaciously to it. The test is to see how long this really does stick. In the meantime it is as razor sharp as any modernist could desire.