31 Oct 2008
Latest Transition Town Totnes Bulletin Goes Online
Thought that on this beautiful sunny Autumn morning (feels like the morning after the Great Flood, given the extraordinary rainfall we had yesterday) you might like to have a snapshot of what TTT is up to, courtesy of our latest Bulletin which was published yesterday. Click here to read it.
ian greenwood
2 Nov 12:56pm
Congratulations on the new TRANSITION format
under “Buildings” The following comment was left “For me, there is a whole area of natural building that urgently needs exploring which no-one is (as far as I know, if you are, please correct me!). Most of the natural building literature refers to newbuild, certainly everything I built was. However, not that many people will ever get to build their own home, most are stuck with the ones they have. How can we use hemp, clay, straw, lime and so on to make the poor quality houses we have sufficiently well insulated and beautiful to enable their occupants to live out energy descent in comfort? This is the next great area of exploration for the natural building movement”.
GOOD POINT – USE NATURAL WOOD CLADDING
I hope the following is of use – it made a major difference on our North Wall – indeed the whole of that side of the house (when I came into a room with 2 external elevations clad last winter in the “cold snap” after we’d done it, it seemed like a heater had been left on) the rest of the house had cooled off as normal in a week but not that room which normally would have been just as cold!!
Short of adding 18 inches of straw-bale and then rendering, an extra thickness of walls which is impractical for most existing houses in village and urban environments, this is what we did with very good results, mostly natural products:
USING Triso Super 10 (ACTIS – France) (30 mm thick)highly reflective multi-layer foil product we got about the same insulation value (EXTERNAL INSULATION IS IMPORTANT TO CAPTURE THERMAL MASS) ..the same ins value as a straw-bale in only TWO INCHES or so including 18 mm T%G boarding about 0.2W/sq m degree C. Because it is a warm surface condensation is not a problem – it is vapour proof so water-vapour cannot condense because it cannot pass through the product.
The boarding does not need painting. As long as there are no exposed ledges/water traps – droplets evaporate off – it functions a bit like a well-constructed fence – if vertical boarding is used (the timber then looks a bit like the natural grey wood so common in France) it would improve the longevity of the building by protecting the external walls and improve the value because people would know of its insulation value. Using Natural wood we avoid render which can need painting, can fall off etc, etc, but render is an alternative where desired. Or a new skin of brick at ground storey height?
IMPORTANT THINGS – NO air leakage from Behind the Triso super 10:
for maximum effectiveness: Treated tile lath screw-fixed to brickwork at ~ 300c/c and silicone mastic sealed at the perimeter between batten and brickwork. Next – fill in with vertical battens at about 450 c/c first layer. Apply Triso – edges captured between the next battens screwed on top at the perimeter so Triso is captured between, then horizontal battens as second layer at 450 cc approx so most of the battens only compress 50 mm sq contact area of the Triso where the battens cross each other.
Then apply vert boarding as normal cladding – paying attention to flashing correctly to shed water outside the cladding (even to form drip off the flashing if at all possible). Old pond liner is ideal for cheap flashings in place of wide lead where difficult behind SVPs etc, which can be moved out 50 mm for most of their length and re-fixed.
On our house the cold side became the warm side with a lot less heat input. It is the most effective energy saving measure I have ever done! in 30m years as a Building technologist! But we would not want all the fronts done like this the front elevations are essential for the Character of Britain! I am now trying to get government to cough up a subsidy because the savings nationally would assist the Transition, even holding the price of gas/electric down if done on a wide enough scale. As you TRansitioners know it must be done quickly. By all means contact me and respond to some rough documents on http://www.STEERglobal.org. We need to act to get an announcement in the Pre Budget Report due out in only a couple of weeks.