Stonework on the garage gable wall

Garage door quoins
We built up stonework for the north-west gable wall, to the left of the new garage wall, alongside rebuilding the front-door area, as they are adjacent. Once this was at lintel height, we spent a couple of half-days building up the quoin stones to the right of the garage door. This was really close to the corner of the building, so the stones were generally rather skinny. I had to sculpt the bottom few stones to shape and used steel strapping to tie the tops into the existing stonework, to add strength. I could then add larger quoins to get up to lintel height, again strapping them to the existing stones. So we created a decent & solid edge up the wall from a very un-promising start.

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Garage door granite lintel
Which mattered, because the lintel was 150mm deep, 300mm high and 2.7m long, so was a big beast. We reckoned it weighed around 400kg. I got our chain hoist slung from timbers propped over the top of the concrete blockwork and strapped them to a scaffolding bay behind the wall. We lifted the lintel it with an effort, got it above the height of the padstones, lowered one end onto a padstone and were able to lower the other end into place without too much damage. We built the rest of that course of stonework, fortunately it tied in exactly with the existing quoin on the right had edge of the gable wall.

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Garage door structural lintel
The next day we made up a bucket of quite dry lime mortar and put a bed at each end of the granite lintel. We hoisted a Catnic steel joist up and rested it on the mortar pads, leaving a minimum 10mm gap between the granite and the steel. It was ridiculously light compared to the granite. The following day we were able to start building a 200mm course of granite facing over the front 100mm-deep shelf of the Catnic, then extend it to a full-depth course either end. Again it tied in very well to an existing quoin. It very effectively disguised the Catnic, there will be a wider line to be pointed at the top of the granite and that is all. After filling the lower half of the gap behind the Catnic with squirty foam, we topped it up with lime mortar and waste material. We left the wall at that point to go off before we carry on building above the Catnic. We will point in the gap when the wall above is complete and the Catnic had deflected as much as it is going to.

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North wing windows & doors

The north wing has two doors and three windows on the south wall. The doors are missing their decorative granite lintels, but are otherwise good to go. The three windows have sills, one already has quoin stones  and I got another window partly built up, before we headed south. All three are missing granite lintels. The north wall has two windows and what will be the front door. Both windows have sills, one has quoin stones, both are missing the decorative granite lintel. The front door is still only blockwork with a pair of concrete structural lintels in place, otherwise it needs the full works – sill, quoin stones, stonework to either side of the quoins, an extra concrete lintel and the granite lintel.

These all need sorting before we can finish the raised wallheads and get the rest of the north wing trusses on. Having got so far with the sarking on the east wing roof, Ric set out to do as much of this as he could before he finishes in the second half of October.

South wall: He completed the quoins in the window I started and in the remaining window on the south side. He finished them both up to lintel height, added the extra concrete lintels, then put granite lintels over all five openings. Three of the openings already had the raised wallhead blockwork above them, these left 50mm of headspace to lower the lintels down into their sockets. Ric used the eletric hoist and the cradle for lifting blocks. He rested the granite lintel at the end of the cradle and lifted it up as delicately as possible. He found he was able to get the lintel to height, then lift it up a small enough amount to slot it back into place. Neat. For most of them, he was even able to fill the gap between concrete and granite lintels with concrete, from above. The door at the east end was more of a problem because it had trusses over it and Ric had fixed the fascia board in place. He ended up squirting foam up into the gap. Once this had all gone off enough, he filled in the gaps in the raised wallhead, meaning that side is ready for the rest of the north wing trusses!

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Moving trusses: We had no real choice at the time but to rest our north wing roof trusses against the north wall of the north wing. The only place with enough space was right in front of one our incomplete window openings, meaning Ric could not work on it without moving the trusses. He did the manful thing. He cut the birds-mouthes (the cut-outs on the rafters that rest on the wallplates) on every single raised tie and trimmed the end of the rafters to approximate length and shape. He lifted the trimmed trusses over the wall and stacked them inside. He got them as vertical as possible and left them in three groups down the length of the north wing, securely strapped to the wall. Given the amount of ladder-climbing and the fact that the scaffold tower is a complete pig to manouver, this could not have been a fun job. However, we did then have the north wall clear to finish doors and windows!

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North wall: This left Ric a couple of days to do what he could with the windows and doors in the north wall. He got the granite lintel over one window, then installed the granite threshold for the front door and laid the first quoin stones. The front door is close to our newly constructed blockwork for the gable end we demolished last year and we will have to do the stonework for both areas together. The gable end projects 220mm out from the line of the north wing, so he fitted the first quoin stone at the junction of the walls. Hopefully, Ric will get the remaining window up to lintel height, so that next spring we will only have to get the front door stonework completed, then fill in the gaps in the raised wallhead. I expect we will run the stonework at the same time onto the gable end as far as the garage door.

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At which point, we can get the rest of the trusses up! This should be comparatively quick and easy since all trusses are at 600mm centres, the wallheads are parallel and they are the right distance apart. We do need to trim the concrete blocks to make room for the bottoms of the rafters and let the birds-mouths rest on the wallplate. Putting sarking on should also be a little quicker than on the east wing, because the 600mm centres will mean less cutting boards to size.

More windows, blockwork and rubble walling

Alongside building the bathroom window opening, we worked on the remainder of the east wall of the east wing,. We had decided that the southern-most of the three windows in the wall would use our complete set of splayed quoins stones i.e. where the window opening widens out towards the back of the wall. This will be in the room with the gallery and the large (3m x 3m) south-facing window.

We did not know exactly what space the quoins needed, so had not laid the backing course of concrete blockwork at that end of the wall. They have a lip at the outside face, with the window being fitted at the back of the lip. Because the stones were rather roughly finished, it was not clear what the angle of splay would be, until we installed them. So we laid sills in the second and third window openings, then laid the first pair of splayed quoins. I guessed the angle of splay and laid concrete blocks back to the inside edge of the wall. The following day, we laid the next pair above, I had not been not too far out – I laid a fillet of block on one side, to line up with the second quoin, the other side needed no adjustments. As the third and fourth quoins went on, it all became much more clear and I was able to lay the concrete blocks up to the height of the lintels and paint on the synthaprufe. Ric worked on the middle window to keep pace. We laid the remaining concrete structural lintels and the outer granite lintels on both openings, I then finished the concrete blockwork right up to original wall, painted on the synthaprufe and filled the gaps behind the granite lintels with concrete.

And that was my time used up, I had to head south again. Ric stayed on for another two weeks to finish of the east wing wall and then do what he could on the north wing.

Our first home-grown window opening!

Having got our bathroom window sill in place, I got going on forming the window opening. We had decided a while ago that all three windows on this length of wall would use red Peterhead granite quoins. I levelled up the granite walling to just above sill height, picked my first two quoin stones to match the coursing of the rubble wall and trimmed the corners so that they overlapped the sill by 30mm each side and lined up with the concrete blockwork at the back of the wall. I laid them in lime mortar and pinned them in place. It was quite straightforward to build the quoins up, alternating the direction they lay (along wall, across wall, along wall etc.), four courses each side. The door frame will be set back from the outer wall face by 215mm, less the length of projection of sill over wall face, less the length of overlap of frame onto the back of the sill. This is around 150mm and any gaps behind that we could fill out with concrete block, to save stone. I built back from the quoins to original wall as I went, to stabilise the whole thing.

I left the quoins a day for the mortar to go off enough, then Ric cut the third concrete structural lintel (the other two were already in place supporting the concrete blockwork) and the outer granite lintel and lifted them into place, with a gap between them. I made a wooden framework to fit under the window, wedged it in place then filled the gap with a dryish concrete mix. I tied a luggage strap around the two lintels and wedged a stone in the top between the lintels, to hold everything in place until the concrete set. Which it did by the following morning. And that was our first self-constructed window opening. There are already 5 pre-existing window openings, but it was still a great feeling to do our own!

Garage progress

We need to do a lot of work to get our garage area, in the west wing, sorted. We took the entire north gable-end down, we need re-construct it to include the garage door. This requires installing two Catnic structural beams and a 2.7m x 300mm x 150mm granite lintel. We also need to block up the large opening in the side wall and reconstruct the window, where we had to extract a wooden internal lintel and replace it with concrete ones. The existing granite in that wall is sound but not brilliant. As an aside, we will probably get our incoming electricity supply moved to an in-wall box set into the opening we are blocking up – the current box is surface mounted and blew open over the winter, permanantly damaging the door.

On this visit all we really wanted to do was prepare for granite lintels arriving later in May. Ric & Geoff had already blocked out the back leaf of the gable-end wall, to lintel height. Before we arrived this time, Ric perched one of our two 3m Catnic metal beams across the garage door opening and continued the gable-end blockwork upwards to the sill height of the upper-floor window, finishing tying the blockwork into the remaining granite. He also built up the side opening towards old wallhead height and placed the concrete structural lintels over the side window opening behind the exterior granite lintel.

After we headed south, Ric intended to build up quoin stones either side of the garage wall, to a point where we will see if we can get the big granite lintel dropped directly into place when they are delivered – the current plan is that they will be delivered to the local builders merchant, in Ellon. They have fork-lifts and can deliver them to us. We expect this to be in the last week before Ric heads back to Cornwall. With the granite lintel in place, we will place the second Catnic directly above, with a gap of a couple of cm. We will start rebuilding the granite outer skin, including across the front-facing shelf of the Catnic. With a bit of care, we should be able to completely disguise the steelwork. Once everything has had a chance to settle, we can pack mortar in the gap between granite and steel lintels. That is the plan, it should ensure the granite lintel has zero loading on it, other than bearing its own weight…

Concrete blocks and lintels

To recap, all our new and replacement rubble walling must be constructed with an inner skin of standard concrete blocks laid on their sides. We tie the blockwork in to existing walling with ‘swallow-tail’ wall ties that screw into sound boulders in the old wall, with the swallow-tail part eventually getting mortared into the blockwork. We include stainless steel mesh reinforcement strips, bedded in the blockwork mortar and sticking out the side, to be able to tie the granite outer skin to.
When we are ready to build the outer skin, we paint a liquid DPM (Synthaprufe or, in our case, a cheaper substitute) on the outer face of the blocks, wait the short time for it to go off, then build the 250-300mm skin of granite rubble, as close as possible in style to the adjacent walling. Given the old walling was 450-500mm thick, some of the boulders are too wide for the new construction – we use the feathers & tare to split them.
There is no reason why the replacement walling should look any different to the original, once it is all picked and pointed.

Also to recap, all the wallheads are to be raised by 450mm. This is to lift the roof by some 45cm and give us headroom in the upper storeys of the east and west wings. We are doing the same to the single-storey north wing, to maintain the proportions of the building as a whole. We do this by laying two courses of concrete blocks widthways across the wall, lined up with the inside edge. On top of this we place two courses of blocks laid lengthways, also aligned with the inner face of the wall. The roof trusses will bear directly on wallplates laid on the raised blockwork. We completed some of this blockwork a year or two back, then got distracted onto other priorities.

Back last September, Ric and my youngest brother, Geoff, started building up the inner skin of concrete blocks across most of the building. They made good progress, getting many of our window openings defined and building the blockwork for the two gable ends in the west wing, to ground floor lintel height. We got a lot done, but had more still to do. Ric has since put concrete structural lintels over two windows and a door in the west wall of the east wing and raised the blockwork above these to the height of the old wall head. He had bult up to new wallhead heights on the remaining granite wall.

On arrival, we carried on the good work. Ric worked on the east wall of the east wing, forming the northern of the two new windows we opened up at Christmas. He could not block out the other window because we will use our splayed quoin stones and will not know the exact size and shape until we do it. This done, he took the top off the north gable end, removed the wooden inner lintel and put concrete ones in its place. He built up the inner course of concrete blockwork. The outer granite lintel is still in good condition, so was left well alone. He moved to the northwest gable wall and built blockwork above one of out Catnic steel beams. He kept going until he reached sill heights for the upstairs window.

We started by placing concrete lintels over all openings in the north wing that were ready. Where this was over new blockwork, we had room to place 2 out of the three required lintels – the third one will have to wait for us to build the granite outer course. We tidied up the blockwork above, to the level of the old wallheads, but cannot raise it to the new height until the granite outer skin is built. Over original walling, we placed all three concrete lintels, just leaving room at the front for the decorative granite lintel, then raised the wallhead by the required 45cm. We had a bit of an issue running the raised wallhead across the concrete structural lintels, the bottom course of blocks tended overhang the outside edge and sag down. We sorted that by using old slate on thinner beds of mortar, it was much better at supporting the blocks until the mortar went off. By the end of our visit, the north wing had raised blockwork over the entire length bar two openings on each side that need granite rubble to be rebuilt to old wallhead height.

This all had a transformative effect – what had been gappy tooth-like islands of old wall quite quickly became coherent and well defined runs. With the floor slab in place, it is easy to visualise the internal layout and get a reasonable feel for what the finished structure will look like. Exciting times, though there is still a lot to do before we can get the roof on.