From this we can see why so many houses came down (around 1.4m at last count)
Wednesday, 29 December 2010
Post Flood Housing survey - Pakistan
Excellent report here by UNHABITAT covering all different types of houses, materials and designs in rural architecture.
Friday, 17 December 2010
Pakistan floods, firewood and recovery
A school front door in Jacobabad. |
So in summer this year the monsoon rains opened up with all the built up ferocity of a planets' worth of energy, heat and smoke from a continent on fire (Russia, Portugal, etc.), droughts across Africa, floods in South America, a mighty freeze in Europe the winter before that has to balance out somewhere. And so it rained. The mighty Indus that flows from the craggy North to the desert South of this amazing country swelled and burst into irrigation channels built by the British a hundred or so years before, channelling water where it sholdn't have been, sweeping away decades of community. Luckily, most people had time to move out before the water (less than two thousand people died, amazingly few).
Camps of returnees, in the shadow of their former homes. Jacobabad, Sindh. |
We decided to visit Dadu and Jacobabad, the two districts al of which lost the most houses - about 150,000 each, and see how people were coping. Photos say more than I could... First we stopped in at a camp, for a few thousand folk
So we travelled through Dadu, a district that lost around 180,000 houses (at 7 people per house that's a lot of people without a home).
So, cooking: See the cow dung drying in the sun, makes for good cooking fuel, saves money. Stuck in camps people don't have access to their usual source of firewood, so they pay about $1 a day for sticks and roots. This exposes a major problem here - inefficient cooking systems. Local landscapes are denuded, there are literally millions of people cutting and chopping their way through the undergrowth and the canopy, to burn semi dry or just green wood to sizzle up their meals. There's little evidence that anyone has mapped out the implication of this over the next five or ten years: what will happen if this continues, this size of population cooking their way through these few remaining trees?
Especially frustrating when you know that alternatives exist that really work: fuel efficient stoves (at least to slow down the disaster), solar cooking (ovens, parabolic water heaters, oil tank heaters, and more), biogas (cooking from the gas of our poo, or our cows poo, or both).
The humanitarian machine is incredibly fixed into its way of doing things, but it can change. It's taken years but mainstreaming concepts around gender equality and to a lesser extent protection (human rights) is becoming more recognised. Environmental impact is starting to appear as an overarching / "cross-cutting" issue but most people and organisations don't understand the link between energy, environment and human communities so it's given lip-service and spin. In fact, from an environmental perspective our aid operations are catastrophic. Consider the overall pollutants and carbon emissions of the millions of products we import from the far corners of the globe, the tens of thousands of air flights, air lifts, truck days and so on. Do we count this up? No, don't even discuss it! We are, it seems, immune to the carbon magnifying glass. "hey, we're saving lives out here, don't hassle me with that tree hugging shit" is the general impression you'll get if you bring it up.
Sunday, 26 September 2010
Roof building time / Tempo para a construção do telhado
After many moons of preparation - of walls, lime work, wood research and planning - it arrived, a truck load of eucalyptus wood from near Porto, 140km or so away. With this + one experienced carpenter, our main house roof began.
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This is the only hip-roof we're going to have on the building (alternative to a straight, gable end).
I have been amazed by the skills and confidence of this guys. I ask them if they have any young 'uns coming up behind them, learning their trades. They laugh, regard me as retarded, and explain that no young person wants to do this sort of thing. "People want to learn to design things on computer, not here for real, where it's hard work, takes years to learn". For sure, this isn't something you could pick up in a year or two. It's an art, a lifetime's work. And not particularly well paid.
"anyway" they add "everyone builds their roofs with cement these days". This is a whole other issue, based on a little common sense and no doubt serious financial gain for a few individuals in charge of the concrete industries. But how could the entire architectural and engineering professions have been sold out so easily?
Here's the story:
Carlos, the local Hulk, nudges this half tonne beam and lets the block and tackle take the rest of the weight. |
Day 1, wood arrives and sits like heavy lumps on the ground in front of the house. I expect a day of phone calls for cranes and heavy lifting gear (after having seen João, the stonemason, use his mechanical claw to move stone all around).
These guys are different – they use a block and tackle. A “Garibaldi”. A pulley with gears. They built a super basic frame higher than the first floor, and dragged the first 8m mega-beam up to it, then hoisted it with this simple yet life-changing little device. From the 1st floor they did the same thing up to the roof, and within an hour the first beam was sitting there, all warped and imperfect, waiting.
It was incredible to see how quickly they worked. By the end of day 2 they had created the skeleton of a roof, made from enormous bits of green wood (let it go dry, it's impossible to work they say).
Manuel, lead carpenter, 40 years experience, lining up first beam to go on the roof |
They work with no plans or drawings. The list of materials they ordered was done standing in the empty house, pionting at corners and spaces in the air, pulling figures from their volumes of experience. “8m beam there, 64 rafters to cover both main roof elements, a truss here, and supporting beam there” and so on. Jorge, Mr Sawmill, was there scribbling notes as Manuel fired out instructions. They ignored me and my irrelevent questions.
When it's time to join the wood together Manuel whips out his electric chainsaw, sharp as a needle, and cuts shapes, based on how the wood sits beside another bit. He may draw a pencil line, he may not. A few whacks with a mallet and chisel to clean it up. And boom, it slots into place like it was meant to be. A couple of massive nails to keep it in place and it's hard to see how that roof isn't going to stay in place for centuries – as long as we keep the water out.
a;lksdf
Piecing it together |
Carlos, whacking out some indents to house the angled trusses. |
Temporary brace for the end of roof... Hoping there's some kind of longer term plan for that one! |
Ilie understandably worried at this stage. |
By day 4 or 5, looking more and more roof like... |
What am I doing here? |
Nikita in the thick of it. Learning. |
First he cuts, then chisels |
Then checks |
Then slips it into place. Nice |
This is the only hip-roof we're going to have on the building (alternative to a straight, gable end).
More massive wood, oak this time to hold up East side of roof. |
And floor beams, almost 6m long, 30x20cm size for the kids bedrooms floor... Roof coming over this next. |
I have been amazed by the skills and confidence of this guys. I ask them if they have any young 'uns coming up behind them, learning their trades. They laugh, regard me as retarded, and explain that no young person wants to do this sort of thing. "People want to learn to design things on computer, not here for real, where it's hard work, takes years to learn". For sure, this isn't something you could pick up in a year or two. It's an art, a lifetime's work. And not particularly well paid.
"anyway" they add "everyone builds their roofs with cement these days". This is a whole other issue, based on a little common sense and no doubt serious financial gain for a few individuals in charge of the concrete industries. But how could the entire architectural and engineering professions have been sold out so easily?
Here's the story:
Why cement? Because they are “resistant, waterproof, strong, long-lasting, cool in summer, warm in winter” (quotes from local builders, home-owners). As they have only been built in this way for the last 30 to 50 years they don't yet know the results of this national experiment. In the UK, many buildings made with cement have started to deteriorate within a 30 to 50 year time span, due in part to the inevitable cracking of cement floors, foundations and walls – cracks that allow water to come in, and eventually cause damp within the building, rotting of any wooden elements and so on.
But cement in roofs never really took off in the UK – or France, Germany, the US and most other places for that matter. This means we don't really have a precedent to measure it against. It seems mighty popular in Spain and Portugal so this should be the area to watch. Here are some of the down sides I can imagine with cement roofs:
- Non-breathability. Cement doesn't let moisture pass through, so it can't “breathe”. A bit like a plastic bag. It keeps the rain out, sure, but it also keeps the moisture in. And if you think about how much moisture we generate in bathrooms, kitchens and just breathing around the house... We would need a fairly sophisticated ventilation system to allow all that water vapour out, without letting in too much cold air.
- Money. I have yet to find out how much it costs, per square meter to build a cement roof, but I'm fairly sure it's more expensive than wood. Though that depends what kind of wood you choose. We'll get to that later.
- Carbon Factor. We now know that to produce 1Kg of cement you will emit 1Kg of carbon dioxide into the atmosphere. Multiply this into the millions and you're talking a fairly major chunk of your national CO2 diet. In fact, buildings in Europe are responsible for around 40% of its emissions. So, you want to cut emissions, why not start there, in the building products themselves ? It really is a no-brainer. Trees are like solar panels: they grow with a happy combination of sunlight and water. Cut them down to make houses and plant more, plant twice as many. Make forestry a part of the building industry. Use local timber, not imported stuff from Scandanavia and you cut emissions further. Learn how to use local wood. Get young people learning about this stuff and you may just reduce carbon emissions. Or just screw the planet and build with cement. It seems there's overwhelming pressure around us is to do just this - so many people make so much money from the status quo. Why change it?
I had better leave it there, lest I rant.
Monday, 20 September 2010
Stone building, all summer
Since May it has been stone stone stone on the main house. With João Camula, of Granitos Camula, as our stone mason, wall after wall was taken down, rebuilt - using stone on site and a few imported from nearby. We used hydraulic lime and sand as the mortar in every case. Here's how it has progressed on one of these walls, in June.
Picking apart a wall. They carried on taking it down to ground level. |
João and Amançio getting the first stones into place for the new wall |
View from inside, where the stairs will be built, one day, from ground to first floor. |
Day 2 or 3, new wall coming along. New door decided upon as well:) |
Wall completed, as seen from the East side of Adega, with new handy shelf thing integrated. |
Same wall from above. So here you can see the adega section from West view. Timber frame and straw bale walls to follow, hopefully in October. |
Sunday, 5 September 2010
A wall of straw and clay / Uma parede de palha e argil
The Alambique - timber frame and windows (from Jon and Mary in Scotland!). Shuttering below to hold the straw-clay. |
We've been working on the walls, floors, roof, plumbing, drainage, power supply since May. Now we needed a front wall. We have a few choices for wall material: bricks and mortar, earth bricks, timber frame with plasterboard and insulation slabs, and so on.
Nikita as Paulo's carpentry assistant, building the timber frame. Note the stone wall built below the timber, to keep straw and wood well away from any water. |
The clay takes loads of time to soften up, at least 24 hours. Then it needs whisked, then then the slip decanted into another container. |
Paulo, surrounded by clay slip buckets, showing our Galician friends the right mix of clay to straw, in Donald's old bath. |
Federico on clay stone crushing duty |
Irena, Cesar and Jorge working the clay slip into the straw. |
Then you need to have at least 2 people fluffing up the straw in a container of some sort. On bigger projects people have all sorts of equipment to do this, but these are not available here in Portugal, and if they were they would cost a fortune to rent.
Bugui, Galician yoga and meditation teacher, working with the Zen of Straw |
Cristina, recent Galician resident from Italy, adding her labours to the wall compaction. |
Once the wall sections are done you can remove the shuttering right away. What you have is a damp walls of clay. Looks nice, it's straight and ready for plastering. But not for months! Here's another disadvantage: it takes up to three months to dry properly. It's been 6 weeks since we built this wall and it's been really hot, so it is almost dry inside. But in colder climates this could be a real problem, mould can occur and delays in the building process can cost a lot.
Irena, great friend from Northern Galicia, and child (still at one with her) one of the hardest workers on site. Impressive. |
Me, driving ash stakes through the bales to keep them stacked in place. |
OK. What about thermal performance? Dhanya's research found that the U-value of a 40 cm straw-clay wall can be around 0.239 W/m2K (this refers to the U-value, which is a measure of energy conduction, in watts, per square meter, conducted through a material, for each degree difference on each side).
How does this compare with other types of walls? Well, here's a selection, taken from the Whole House Book:
Wall type U-value
Solid brick (225mm) 2.20
Timber frame with
50mm insulation 0.96
Timber with 100mm
insulation 0.35
Our straw-clay wall
(maybe?) 0.23
Superinsulated house
with 250mm insulation 0.14
Straw bale wall 0.13
The latest UK building codes state that external walls must have a minimum U-value of 0.35 (W/m2K), which means straw clay/ light earth would be considered more than acceptable.
Overall, we are not that impressed so far with straw-clay as a system. It is so labour intensive that this can increase the cost of the job. And it takes a long time... Also, the problem of waiting for it to dry out enough before plastering means that it could delay a construction. A few mice have also moved in...
That said, now the wall is done and almost dry, I think it's going to perform well. But we'll have to see after plastering, and after a winter of rain and cold.
Petrus, building up stone wall in front of the alambique where we plan to build a wooden structure for a veranda. More on this later. |
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