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.

July visit

I was at the steading for a full week in early July, with Ric. The aim was to prepare for our September visit, where we want to get roof trusses up on the east wing and, if practical, part of the north wing.
To summarise where we are with the east wing…

• West wall (facing the courtyard): We rebuilt the doorway and installed lintels over the door and small window in April, then built rubble wall above the lintels to old wallhead height. We still need to lay blockwork to raise the roof to the design height.
• South gable-end: The parapet and retaining stones will need raising to the new roof height but can be done after the trusses go on. At the same time, we need to remove the stub of a concrete lintel that was embedded into the courtyard corner.
• East wall: The pre-existing doorway has been blocked out as a window and we completed the stonework up to sill height back in April. Last Christmas we opened out a section of wall to install two windows. The backing blockwork for one window is complete, the other is not blocked out because we plan to install quoins for a splayed window and do not really know how that will play out. We need to do the stonework (sills, quoins, lintels) for all three windows, complete the backing blockwork, lay the rubble walling, then raise the wallhead to the design height with the four courses of blockwork.
• North gable-end: This needs one side tidying up, replacing missing quoins and the retaining stone (for the coping). The parapet will need raising to the new roof height, but can be done after the trusses go on.

So most of the work on this block translates into:

1. Getting possession of the 41 granite lintels we ordered in March from Lantoom Quarry, Liskeard, Cornwall.
2. Converting three of the lintels into window sills for the three window openings down the east wall of the east wing.
3. Installing the sills, building quoins up the sides of the window openings and placing concrete (structural) and granite (decorative) lintels.
4. Completing the inner skin of concrete blocks up to old wallhead height, where we had demolished original wall.
5. Re-building granite rubble walling in front of the concrete blocks, around and over the window openings, up to old wallhead height.
6. Lay the four courses of concrete blocks above the walling, to raise the roof to the designed height.

Ric was confident we could do it, I was prepared to give it a shot. Being mid-year in northern latitudes, I could allow myself as long working days as I could stand – it gets light at 4am and dark after 10pm!

I brought the strimmer up with me to tame the grass, nettles, docks & thistles, but quickly realised that it was a bit late. The hot, dry weather meant that the perennial weeds had seeded and gone over already and had woody stems – strimming them would be dissatisfying and not very useful.

A flying visit

We had planned a while ago to fly up to the steading over the late-May bank holiday. We wanted to meet up with our granite lintels and sills, however this was not to be. They were delayed and Ric headed south early because there was not a huge amount to do. We went ahead with our visit because we had bought the tickets and car parking, got the dog booked into kennels etc. It was a sound decision – we had four days of wall-to-wall sunshine, low winds and moderate temperatures – warmer and sunnier than down south.

We had a bit of a mare getting home, though – we got back 13 hours later than scheduled. We got to the airport just after 7pm for an 8.35 flight. At 8pm we were told it would be delayed until 10.20pm, then 11.20pm. Then, after 11pm, someone spotted that flightradar was showing the incoming flight, having circled over the airport for a while, heading back over Dundee. We knew it had landed in Glasgow before it was officially announced that a) it was going to refuel and then b) that it was too foggy to land in Aberdeen, so our flight was cancelled. We were near the front of the queue at the Menzies Aviation desk where one hapless individual had to sort out over 100 concerned passenger, so we had only an hour to wait to get sorted out. We had little choice – wait two days for the evening flight out from Aberdeen or transfer to Glasgow for the 7am flight to Luton. So we taxied across to Glasgow, arriving 5am, got our flight out, got a train from Luton to Gatwick, transferred from the south terminal to north then got a bus back to the long stay car park. We knew which zone we had parked in, but it took about 40 minutes to find the car, we had not noted down the row number. Anyway it was a fairly quick run home, getting back about 2.30pm.

Back to the steading: We decided at the get-go on two areas of work – tidying our hedging and carrying on with concrete blockwork.

Weeding & tidying

With spring well underway, our hedging needed weeding and tidying up. In fact we could usefully have run the strimmer over most of the garden, but I had taken it south last year so we could keep our allotment in order. I will take it back up in July.

Jill worked her way round the entire plot, pulling weeds, removing tree guards, removing dead stuff and replacing the guards. The failure rate is still reasonably low, even in the areas that flooded over the winter, probably less than 1 in 10 overall. Most plants have broken well clear of the tree tubes and are starting to bush out, but for whatever reason, we have patches where they are languishing – it may be the wrong species in the wrong place or just poor ground. We had problems over the winter with the wind blowing some of our tree netting over and the rabbits had chewed the bark off a couple of our fruit trees. We will look to do a proper inventory later in the year and buy a small batch of replacements. We will probably not do anything where one plant has failed, we will expect the others around it to fill up the gap.

Concrete Blockwork

Ric had left the mobile bay of scaffolding in the master bedroom area of the west wing, for us. I carried on from where Ric had left off – he had constructed the north gable-end as high as the sill for the upstairs window, then worked around the west wall getting blockwork up to old wallhead height. I blocked out a shortish length of original wall to new wallhead height (four courses of blockwork, 2 across the width of the wall, 2 along). I then worked on the south gable-end. This had been taken partly up to ground-floor lintel height last September. I built it up level to old wallhead height, going round each corner and tying it in to the original walls. I then extended just the gable-end upwards to the same height as Ric has with the north gable-end i.e. to sill level for the upper story window. We ran out of time & mortar to do more, with just two blocks not mortared into place. Looking at the gable-end that we have part-raised to new roof height, we will need a few more blocks to tie the gable-end in to the raised blockwork on either side wall – at worst we might need to use wall-ties.

We can carry on with the concrete blocks, getting the west wing gable-ends completed, raising the last piece of old wall to new wallhead height and blocking over the new piece of wall we finished in the east wing. Beyond that we need to get building the granite skin in front of the blockwork in the remainder of the east wing. And that needs us to have the lintels and sills.

Looking at my spreadsheet, we have bought 34 pallets of blocks to date: 2912 concrete blocks, with around 450 not yet used. Six pallets-worth of 10N ones went underground to get our foundations up to DPC. The rest have been 7N and above ground level. With the tops of two gable-ends to complete and nearly  half the wallheads still to raise, we might only need an additional 600 blocks – another 7 pallets! I doubt we will be sorry to see the end of them. In theory every single one of them will disappear from view.

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…

Gable-end facelift

The east wing of the steading has two gable-ends. The south end is complete & intact. The north end is sound, but in poor condition at the upper end. The retaining stones  that held the coping stones in place are long gone, as are the upper quoin stones. Some of the coping stones were missing, the remainder were threatening to slide off and we removed them a couple of years ago, for safety. This gable-end needs sorting out before we can get the roof on, plus we need to raise the roof by 45cm (four courses of 100mm concrete blocks + mortar lines) over the original wallhead height, so both gable-ends need to be raised as well.

The gable-ends are to be constructed (as they are now) in the traditional Scottish manner. The outer 300mm is a parapet that should be 150mm above the slating, with the coping stone above that. The remaining 200mm of wall is rough-finished, just under the sarking board and slates. The sarking projects out from the last truss, which will be tied in to the stonework of the gable-end. DPC runs under the coping, down the parapet and over the sarking, overlapping with the roof breather membrane. We flash lead over the exposed DPC, down onto the slating

Tidying up the north gable-end is a tricky proposition – we need to work out where the new roofline will be, given what we know about the proposed construction (raised-tie trusses) and a guess about the depth of the top chord above the wallplate (we assume 180mm at the 42-degree angle). We assume 22mm depth for sarking and 30mm for the slating. We calculated, quite accurately, from that where the retaining stones need to sit, so we can build the gable-end corners to the right height to support the retaining stones.

Enter stage right, a dummy roof truss that is exactly the right size to fit across the raised wallheads and exactly the right slope (42 degrees from horizontal). Ric created the truss and propped one side up in the correct position, using a length of wood. We cross-checked the dimensions and slope, realised it was 50mm too narrow, reconstructed it in-situ and screwed it onto the stonework to stop it blowing away. So now we could work out accurately where the retaining stones need to rest.

Enter stage left, the batch of granite we bought from our neighbour a couple of years ago. It is mostly quoin stones but, significantly, has two pairs of retaining stones. These are like over-size quoins, with a distinctive hollow cut into one end of the upper surface. The hollow allows the lowest coping stone to lodge in it and supports the next coping stone up the slope and so on. They are about the largest stones we will be handling apart from the lintel over the garage door.

With a level to work to, Ric rebuilt one side of the gable-end with quoin stones, let it go off for a couple of days, then we very gingerly hoisted the rather massive retaining stone into place. It was then a quick job to run blockwork up the inside of the wall, with just enough room for the finished roof to cross over to meet the parapet. Ric will repeat the operation on the other side of the gable end. We will leave completion of the parapet until we have the roof on, just in case we need to make fine adjustments.

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.

2018 shopping list

As far as we know, we need to buy the following:

• Granite lintels, cills and thresholds – from Lantoom Quarry
• Around half our concrete structural lintels – Having bought a whole load of 1.5m and 1.8m lengths a year or so ago, we need to get 18 x 1.2m, 8 x 1.5m and 8 x 1.8m ones. We can do this by buying 4 x 3m & 10 x 3.6m lintels and cutting them.
• An initial tonne of NHL 3.5 lime.
• A truckload of sand, probably from the Bridgend quarry near Tipperty, for lime mortar
• A heavy canvas that we can arrange over scaffolding to protect us and the walling from the elements.
• A tarpaulin to cover the sand.
• A truck load of 440 x 215 x 100 concrete blocks
• DPC and other sundries
• Locking castors for our scaffolding so we can run a bay around the concrete slab for working inside.
• A silt trap so we can install our linear drain in front of our garage & front door.
• Blockmix, sand & cement to build a concrete apron in front of the garage up to the linear drain.
• A bilge pump to clear sludge out from our concrete tank

Depending on progress with walls, we may need:

• Structural timber to support roof trusses at each end of the north wing (where we demolished the internal rubble walls)
• Timber for wallplates, truss clips, tie-down straps etc.
• Roof trusses
• Sarking boarding
• Breather membrane and tape (may be a cheap temporary fix to protect the roof, to be replaced when we are ready to slate)

Methinks this will stretch our finances until we can sell our current house and I retire.

A Recap & some odds and ends

We were in Aberdeen over the Christmas and New Year period, mostly for social reasons, but with the intention of opening up two more windows in one of the steading walls.

Ric & Geoff had  stayed on for some time after we finished our September stint. We missed the last pour of concrete, in the east wing, and whilst they had made good progress on blockwork before we left, there had been plenty left to do. So our first visit was a chance to catch up on progress and check the state of the site.

Floor slab

We now have all our sub-floors in place. They had done as good a job of the east wing as they had on the rest. All are within a cm or so relative to each other and across each slab, apart from the garage floor which is 15cm higher and is the finished surface. We had not cut the expansion joints that the warrant requires us to do, for any continuous area over 30 square metres. Technically they are needed to provide a line of weakness in the event of contraction, to avoid random cracks across the slabs. However it had been raining whilst the slabs were laid and they were all under a cm or two of water when we arrived, so I expect there had been little scope in between for expansion/contraction. There were certainly no signs of any cracking, although the top few mm was starting to spall off in place, assisted by freeze & thaw. I expect we will cut the slots when we re-start work in April 2018.

Floor slabs

Blockwork
All our replacement walling has to have an inner course of standard concrete blocks laid on their sides i.e. 212mm wide. In the time they had available, Ric & Geoff got every opening that needed blockwork built up, mostly to lintel or sill height.

Having had misgivings about the whole issue of demolishing walling and rebuilding it, I was heartened with how well the blockwork tied in to the existing walling. For example Ric had started to sort out a particularly tricky piece of blockwork where the east wing joins the north wing on the courtyard side. We had removed a lot of granite because it was in poor condition and the adjacent door opening was a fairly shapeless 3-dimensional gap. He had cunningly tied in a column of blocks to form a neat internal corner that we can key quoin stones into, to form one edge of the door opening.

They had got two concrete structural lintels in place over the main bathroom window and had the padstones ready in several others.

They had embedded strips of stainless steel mesh into the blockwork at intervals, to tie into the new stonework. This means that when Ric is next up we can paint on the liquid DPM and get started on stonework, assuming we have our replacement sills and lintels. I am hoping that, once we can get the structural lintels on top of new granite, we can block out the wallheads ready for roof trusses separately from getting the outer, decorative granite lintels in place – if we need to. I expect that, if we want to go for getting roof trusses on by the end of the year, we will concentrate on building up the load-bearing walls at the expense of the gable-ends. Again, if we need to.

New/rebuilt walling

Wind

We had worried a little about the gales in November and the cold snap in December. The good news was that the only wind damage was to our builder’s fence panels, that were mostly horizontal, and to our electricity meter cupboard, where the door had completely blown off. The latter unsurprisingly had damaged hinges but I sort-of put it back together and leaned a solid lump of wood against it until we can do something more permanent – possibly some sort of strap that we can use to hold the door in place. As for the fence panels, we stood them up and used a couple of stout timber props tied into the panels to stop them blowing over again. I hope. We were particularly pleased that our shrub-guards netting survived the gales, having blown away twice over the least year!

All our shrub guards passed with flying colours! They survived the gales.

Drainage

It has rained quite a bit in the area over the last few months and we noted that…

1. Our flooding problem in the track and driveway area is completely fixed!
2. The short section of hedge on our north boundary right next to our track is still under water and we will want to run a short French drain to connect to the one Ric installed last year across the driveway.
3. The east boundary that had flooded around the time we put our fencing and hedging in, was not too bad, mainly because water is no longer running off the fields the other side of the fencing.
4. We will need the planned linear drain in front of our garage door, because water was coming of the track and ponding up. Not much, but it will make a big difference.
5. The mystery excavation under the boundary fence between ourselves and the holiday let had filled with water to 40cm below ground level. I expect that simply reflects the water table in the winter and explains why…
6. The bottom of the plot around out soakaway has some flooding, including a section of boundary hedging. We do need to look to a) do a bit of landscaping to make sure it does not pond up and b) see if we can help get surface water off site a bit quicker.
7. The concrete sump that our septic tank temporarily drains into had water up to 40cm below ground level.
8. A small point, but the drain cover is now in place over our concrete surface water tank, there is one less thing to fall into now. We did not get round to clearing the sludge out from the tank, I need to hire a bilge pump at some point.

So we are clearly not quite there yet, We need to do some minor drainage engineering. Given the high water table, we will be very interested in how our raised drainage mound performs as and when we get it in place.

Caravan and stove
The caravan was in good shape and did not look wind-damaged, but is starting to look green from algae. The drain cocks Ric has installed in the water supply meant the water heater was completely emptied and should be good to go next time we are in residence. The stove was installed in the caravan and Ric had had a test firing of it. The stove does look tiny, but we have high hopes for it.

It looks tiny, but is was highly recommended.

The stove pipe should be a good radiator.

The double-layer section o fpipe should preserve teh roof where it goes through!

Rodents
We have a bit of an issue with small furry mammals. They had got in to the caravan again and must have been desperately hungry. They had found the gauntlets that came with the stove, made of some sort of leather, and had consumed quite a large chunk of one of them. They had even come across a pair of ear defenders in the bothy that were not out of chewing range; They had eaten their way through much of the soft plastic – the foam soundproofing and the vinyl over the earpieces!

The bothy doors
When we built the bothy doors, two years ago, I made them a bit of a tight fit. By the time we got up this time around, the wet weather had made them expand a bit too much and we could no longer close them. I borrowed an electric plane from brother-in-law Bryan and took several mm off one door and painted the edge with preservative. It mostly sorted the problem, there is one point where it catches a little, I will see if it still a problem in the spring.

The tools for the job.

A satisfactory conclusion…

The weather
Having been up in the area off & on over 30-odd years, I got in the habit of expecting one or two falls of snow over Christmas/New Year. For whatever reason though (and yes, I do believe in man-made climate change), the last decent fall was way back in 2010.

• In 2013, when we first discovered the steading, the weather was chilly and variably windy and damp, but not cold enough to snow.
• In 2014, when we were putting up our fencing, it was well below zero, but still, dry and sunny, apart from one day of wind and sleet.
• In 2015, when we put the new doors on the bothy, it was chilly and damp.
• In 2016 when I dug out an inspection chamber do re-route some pipework, it was again chilly and damp.
• In 2017 we had the first significant fall of snow over the period, in seven years. We only got an inch or two, but it stayed for days, iced over and became quite a hazard. The combination of uneven ground, a capping of ice, melt-water and poor grip on my work boots meant that I landed on my bum several times a day and got quite adept at collapsing gracefully. Driving on the local back roads was exciting and the floor slabs became like skating rinks.
• I had left the dog’s water bowl outside and it had a good crust of ice on top. I lifted it out and observed an impressive array of ice crystals that had grown at angles down into the water.

Not much depth of snow, but it iced over and was lethal.

This layer of ice was on teh dogs drinking water bowl. These amazing ice crystals had grown down into the water!

Building our blockwork up to lintel height!

We bought a truck-load of concrete blocks last year, expecting to use most of them getting the wallheads blocked out. That is still a work in progress, so we used the dumper truck to move blocks 40 at a time to the two gable-ends and to all the openings that need squaring up or converting to windows.

We went over the building warrant plans to work out exactly how the damp proof course was to work. We used 90cm DPC, wide enough to cover the full 50cm width of the foundations and to get up and over whichever leaf of blockwork was higher that the other – the inside at a bit above finished floor level, the outside at ground level + 150mm. It was to be bedded in to mortar below and above, then the blockwork on top of that. We had already decided to use cement mortar for the first metre upwards, because it will be tanked on the inside and have DPM painted on the outside. Above 1m, we used lime mortar. The blockwork will still have the liquid DPM painted on, but it will make the wall more breathable into the narrow 25mm cavity between the wall and the timberwork/insulation .This is to help keep the wall dry, not to benefit the living space, which has a vapour barrier just inside the plasterboard.

We tied the blocks into the existing walls every 3-4 courses with Bluebird stainless steel swallow-tail ties. We cut 50cm strips of Expamet expanded stainless steel mesh and bedded these into the mortar at 90 degrees to the blockwork every 4 courses and at approx 1m intervals. These will be tied into the rubble wall when we get to that point.

Geoff worked on the big gable-end, the big opening in the side wall of our garage area and the area between the garage door and front door. Ric worked on the smaller and more fiddly openings. The windows that were doors need to go up to around 700mm or 800mm and already have the quoin stones in place, so will simply need lintels above the blockwork. The new openings, the ones we needed to widen and those that were brick/block lined additionally need blockwork up each side to form the window /door opening.

Geoff & Ric made really good progress and only stopped once they got blocks to lintel height.

New/rebuilt walling

The first of teh blocks we need in the gable-end.

The pilehas grown…

The DPC is in place.

A corner of the gable-end wall is being laid on the DPC,itself beddedonto the slab DPM.

Here is a swall-tail wall tie in place. The tie is screwed into a hole drilled in a granite boulder, the swallow tail is bedded into the mortar.

This is the east edgeof the gable-end wall, showing what was once a door converted into a window.

The gable-end wallheads upwards, teh upper courses are mortared with lime.

This is the gable-end wall at lintel height!

The water supply and the three power cables all in place in what will be the power room.

The bathroom window opening, to be built up 70cm.

The old garage door is to be fully blocked up – it overlooks our neighbours driveway and will have our air sourced heat pump on the other side.

Preparing to rebuild walls

Getting the floor slab in place was quicker than planned, plus my brother Geoff stayed on for three extra days, so we wanted to get on to the next big job – re-building walls. We need to do this so that we can finish raising the wallheads, in preparation for putting a new roof on.

Not having expected to get this far on, we had quite a bit to do before we started laying blocks. For example, with the floor slab in place, we could accurately measure heights over the entire footprint of the steading and compare with the building warrant plans.

New/rebuilt walling

Single-storey wallhead height: So the height from finished floor to wallhead height, on the single storey north wing, will be 2170mm. The architect has specified doors that are 2050mm high, leaving 120mm between the top of the door and the wallhead. All the windows in that section are designed to finish at the same height – 8 openings in total. This is significant. The plans assumed we would have 150mm above doors & windows i.e. we would need decorative lintels because they will show. The best measurements I took before we had a floor slab convinced me there would be no space, so we could get away with structural lintels only.

It is good that we are close to what the architect planned, but it means that granite lintels are back o the list, but we are very short of them. Most that we removed were cracked or were concrete.

Ric suggested that we get what lintels we have and consider sawing them down.

Fortunately we do have one lintel that is long enough to fit over the 1.5m front door opening – it used to be over the old garage opening which is on the way to being blocked off.

Structural lintels

In general we are to use 3 or 4 (depending on the depth of the decorative outer lintel) 100mm wide x 220mm tall reinforced concrete lintels over all our openings. We bought a whole lot of 1500mm and 1800mm lintels months ago, in anticipation, but will need a small number of longer ones.

We looked separately at the garage opening, which is 2440mm wide and needs 200mm bearing either side – around 3m in total. We have no chance of getting a decorative granite lintel that would survive long un-supported. So we looked at steel lintels and discovered the Catnic CM81C model that has the same 100mm x 220mm profile as the concrete ones, plus a 100mm shelf that would support the outward-facing lintel. They are lighter, stronger and probably cheaper than the concrete ones. We found a modification, by the structural engineer, to the architect’s instruction, that show a ‘T’ section Catnic ‘or equal’ for openings over 2m. So it looks as though we should be able to use two of the Catnic lintels back-to-back and make our lives a little bit easier.

New wall profile

All new walling is required to have a 220mm course of concrete blocks on the inside face i.e. standard concrete blocks laid on their sides. This is what we want to work on during this visit. They are to be tied in to existing walling at either end and to have expanded stainless steel mesh strips that will tie in to the granite outer facing. As we build the outer granite, we will first paint a liquid DPM on the outer face of the blockwork – Synthaprufe or equivalent. This will lap down to the damp proof course, on the foundations.

Furthermore the inner face of the whole external wall – blockwork and granite – is to be tanked to 1m height, over a sand-cement render, then horizontally over the concrete slab by 1.5m. The tanking will lap both the DPM from under the floor slab and the DPC. In an effort to improve the breathability of the wall overall, we will use lime mortar in the blockwork above 1m.

A particular challenge with this design is that the granite outer face can only occupy 250 – 300mm depth, yet it needs to integrate completely with the style of building either side of the new stretches. The original walling very clearly was built in courses. Each course had large stones at the base on the outside, held up by a framework of smaller boulders on the inside face of the wall and between the big stones – with lime mortar walls, the stones support each other and the lime mortar stops them moving. A second row of large stones was built over the first one, with some overlap. This was filled then out with smaller & smaller stones until the upper surface was completely horizontal. They repeated this double-banding upwards, spaced to tie in with the various quoin stones.

It looks like we will be spending quite a bit of time splitting our large stones to no more than 250mm depth.