Extra wide U
Because we did what Michael Reynolds warns people not to do - that is, to go off plan which adds extra complications and costs. We've added extra complications and costs! I'll summarize here what we've done (look at the 'Putting the lid on' pages to see photos and more detail).
We made the main U 7m wide instead of the normal 5m. This means that we needed to add strengthening columns in the middle. Adding columns means digging foundations and filling with cement. It also meant sourcing a 6m long beam which sits on the 2 columns and supports the weight of the roof beams. All these beams and columns were ordered from our local carpenter and are Spanish grown. They're round trunks as you can see which look lovely and natural but gave the architects headaches - apparently there's no way to measure their strength so earthquake calculations were difficult.
Ceiling planks and wood treatment
On top of the beams go the ceiling planks. We sourced these from a wood supplier in Albox - Maderas Ismael. They have palettes and palettes of wood that has been sitting outside for years. We liked this 'old' seasoned wood so walked around to find a palette that had sufficient for our needs in the right sizes.
The books say to buy pressure treated wood, which basically means it's been treated at high pressure with wood preservative. Non of the local Spanish suppliers could source this type of wood for us, although we've subsequently found a British supplier who can. We think he ships it in from Northern Europe. I'm not sure what's best when you think of the extra miles it has to travel, but we spent hours and hours, and days and days treating the wood, my backache (and all the people who helped) was testiment to this. At first we were using a rather nasty, smelly concoction which gave me headaches - even though I was painting it on in the open air. Then we found borax, and what a revelation that was. It's lovely non smelly stuff to use that we bought in a powder from a uk company and mixed with water. Unfortunately EU regs now make it impossible to buy borax in powder form, but it's ok to buy it already mixed. After all, where would we be if we didn't transport lots of water around unnecessarily??
I also opted to put a wash of white paint on the planks as the final finish for the ceiling, I thought it would be easier than doing it afterwards. Big mistake. The length of time it's taken to make the roof waterproof has proved disastrous and we now have planks of rainwater stained white wash. It'll need doing again, sob.
That finishes the main structure of the roof, next comes insulation.