The delivery of all the beams, blocks and steel for the upper floor support was unloaded into the courtyard in early 2008. In France, this type of floor — poured ready-mix concrete on top of a beam and block support with steel trellis reinforcement — is refereed to a an “hourdis” (pron. ‘oardee’ ). The RSJs are ordered to length such that they span the width of the floor area and penetrate about 20 cm into the wall at both ends. They are a sort of short, stumpy capital T shape in cross-section and are set in place “upside down” (inverted T shape ) such that the hollow concrete blocks when dropped in between each pair of beams, rest on the protruding inverted top of the T.
In the image above, you can see how we’ve used a block at the ends of each set of beams to act as spacers. As each beam is positioned, the next beam adjacent to it is then placed with a spacer block. This ensures that when all the remaining blocks are dropped in between the beams, they will all fit! Don’t need to measure anything and this method allows for any small irregularities in the sizes of the beams and blocks.
Those beams at the gîte end, that lay across the width of the building, had to be housed into the existing stonewall. If sufficient loose stone could not be safely removed, then we had to cut slots into the stone with an angle grinder, which created dust clouds worthy of a Saharan Sandstorm! Depending upon the future room layout and stairwells, etc, 2 and sometimes 3 beams were laid adjacent to one another, for greater load-bearing strength at that locality, and to facilitate adding shorter cross beams when creating open spaces for stairwells.
Read Stage 2
Not a lot left to say—the poor old climbing rose on the right of the image has survived all the abuse that came with being in the wrong place at the wrong time. It has wonderful deep blood-red blooms in early summer so we hope it now thrives in its new setting.
And by this stage I’d managed to use most of the good stone, and clear the courtyard of the remaining rubble—although it did make quite a mountain out in the back garden.
Two weeks of subzero weather has finally given way to warmer sunnier weather. Back to clearing some of the mess at the back of the house, including piles of leftover old broken roof tiles. We’d already decided to use them up as ground cover around and between the raised beds in the vegetable garden. In the images, the ‘path’ between the two existing raised beds was prepared by raking level, a porous plastic anti-weed membrane cut and laid down, and some leftover castine (fine clay/chipped stone aggregate) added and tamped flat before adding the broken tile, smashed with a club hammer into small, nicely sized pieces, flat enough to walk on.
Once I had all the arch stones mortared in place, I ran an oak timber on the inside behind the arch to finish spanning the opening. Further dry stone was then added in courses as usual. I wanted two or three shallow courses of stone above the arch to reach the final height.
The image on the left below was taken from the old balcony and the image to the right is a good illustration of ‘the Double’ – one line of face stones to the outside, and a second to the inside, with the middle filled with smaller locking stones.
And the view from the front……………….almost finished. I’ll need to find a solvent or some other method for removing the painted numbers on each of the arch stones. The farmer I bought the arch from had marked each stone as he’d demolished it. Essential maybe, but now, 10 years on, maybe not so easy to get rid of.
The arch stones comprised 16 cut stones, 3 large stones with cut rebates to one side, 4 large stones to the other side ( the ‘second’ stone was actually 2 stones) and then the curved upper section forming the arch itself numbered 9 smaller stones. As mentioned in the previous posts, the crane was used to position the more massive side stones, but I was able to lift and place these smaller arch pieces directly off the scaffolding. I used a little lime mortar, allowing around 12mm for the joins when I measured and cut the formwork.
I left the formwork in place for a few days but in theory, it can be removed earlier if necessary, once the lime mortar has gone off sufficiently—though it is probably safest to leave it 24 hours at the least.
It may be worth stressing again here that should there be any chance of frost, then delay using any work involving mortar. There are preparatory additives available to guard against the mortar freezing before it has fully cured—but they are relatively expensive and not 100% foolproof. If you are forced to take a chance on the weather, then at least find some good insulating cover for the next few nights.
MAKING THE FORMWORK FOR THE ARCH
At odd times over the year, I continued building up the main wall until the time came to sort out the other side of the Archway in order to put the arch stones in place. They’d been lying around for years—lost count of how many times I’d already moved them! I’d roughly measured the span as they lay on the gravel, but now had to position them exactly so that the exact span could be measured and the formwork constructed.
The original entrance way was wider than the width of the new arch, so I extended the wall on the house side by about a metre, setting in the new postbox as I went. Here I did use a little lime mortar in forming the stone housing around the metal box.
I used OSB (Oriented strand board) to make the form for the arch. After laying out the individual stones in their correct position, the board was jigsawed to shape, a second identical piece cut, and then the two ‘halves’ nailed together with noggin spacers.
Once all the drainage pipework was in place and buried in the gravel, we had a delivery of ready-mix and poured the reinforced concrete slab. Then scaffolded up the walls to remove much of the unstable stone to make working in the area safer, and then started laying down the first brick-block courses. Used a laser to accurately set out the first courses.
You can see in the top right image that we’d leveled off the stonework at the gable end of the ruin—it was leaning out somewhat—but we needed to do this as we would be cementing in a reinforced concrete ring beam all around the top of the stone wall to place the wall plate timber to take the bottom edge of the roofing panels. All the mortar mixes were the usual 3 sand to 1 lime ( a medium to high strength hydraulic lime and NOT a pure non-hydraulic CaO ). See the post on LIME for further details on the uses of lime.
Stonefall—happened one evening, June 2007; no-one below luckily. This section was due for demolition—just hadn’t got round to it. Guess I got away with this one with just a bit of scrappy boarding getting smashed and buried by the rubble.
In the image below, I’ve zeroed in on the unstable area prior to the collapse. We were in the process of removing the original large and heavy flat stones along the top of the wall. Once a roof has gone on a crude stone building like this, the weather and rain get in, and then when the frost comes, water freezes, expands, and gradually “blows” the wall. This collapse, however, well illustrates the structure of the dry stone wall (the Double) — the outside face stone collapsed, leaving the inner face still in place.