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.

Slapping out two new windows

We did not stay in the caravan over the festive period, we did not hire the mini digger and we all came down with festive bugs to varying degrees. So we were a bit under-resourced for the one job we did want to get out of the way – pulling down a section of wall in the east face of the east wing so that we can build up two window openings. The two windows are to be 1100mm wide, starting 800mm above finished floor level, There is a 1800mm gap between them. For simplicity we had agreed to make one opening and to rebuild between the windows.

A job that would have taken half a day with the digger took 4 (short) days of manual labour.

We were moderately fortunate with the weather. It was cold, mostly with lying snow and ice, but no very strong winds or heavy rain/snow. By putting enough layers on we kept our bodies warm enough, though we did have real trouble keeping our hands from going numb.

How the wall was constructed
This was as in the gable-end we demolished last year, built up in distinct courses of variable thickness that were levelled off with small stones, before starting the next course. Right at the base of the wall was a double-layer of fairly rectangular stones, slightly wider at the base than the wall above, to form a foundation. Subsequent layers were constructed as a lower row of larger rounded stones, with a flat-ish face, set on the level top of the previous layer. If the stones were irregular, there might be a partial second row of stones keyed into the gaps on the first row. Then an infilling of smaller & flatter stones to bring the course to a level. The inside face was build of uniformly smaller stones with less obvious layering.

This end of the wall looks nearly original and the layering of teh wall is fairly clear, there are 9 layers above the foundation stones.

The inside of the wall is made up of smaller rubble, with less obvious layering.

Unlike the gable-end, though, the large facing stones were mostly quite shallow. So whilst an individual stone might be, say 50cm long and 30cm high, it might be no more than 10-15cm deep. The gap between inner and outer faces had been filled with small pieces of often-rounded rubble.

The thickness of the courses appeared to be determined by the size of the nearest quoin stones. So the thickness of courses was not necessarily the same either side of an existing opening.

The use of shallow stones is precisely what we will need for all the new walling, because we must build it against the inner course of concrete blockwork. It gives me confidence that we can make the end result indistinguishable from the old walling – once it is all picked and pointed.

Demolishing the wall
As with the gable-end, the mortar in the top of the wall was comparatively loose and easy to pry apart and got much tougher lower in the wall. After the first two days we used the SDS drill with a breaker tip, to prise stones apart, it really speeded things up.

I ended up making the opening quite a bit wider than it should have been. Previous tenants of the steading had broken though the wall in several places to…

1. Embed two concrete castings a couple of metres up and a couple apart, that stuck proud of the wall by 5cms or so. The projections each had two chunky bolts sticking up vertically out the top. They must have been used to attach something to the wall. The areas of wall above, behind and to each side of the castings had been packed, badly, with a mix of broken brick and cement mortar.
2. Just above the right-most casting (facing the outside of the wall), a 15cm-or-so, rusty galvanised steel tube ran from the front of the wall, upwards at 45 degrees, to the back, but also at about 30 degrees or so to the right. Again the whole area behind had been badly packed with rubble and cement.

I do wonder whether this relates to the description in the 1964 prospectus for the sale of Slains Estate, where East Byreleask farm is said to have had a ‘Threshing barn and Engine House adjoining’. The large opening in the end of the east wing might well have been  constructed to allow access to trailers of un-threshed grain. Perhaps there was a lean-to structure against outer the wall which housed an ‘engine’.

the concrete castings are a) just left of centre halfway up the wall and on the right, higher up the wall. The galvanised steel pipe is visible above.

The right-hand casting and pipe started exactly where I needed to finish the opening, but the wall was in bad condition above and around the cement work. There was a lot of peaty organic matter and the lime mortar had rotted out. I gritted my teeth and carried on removing wall. The actual rubble/cement mix was very tough so I used the big breaker to get it down in manageable lumps, then break it up again so I could lift it into the barrow and dump it on out concrete pile. I found a 70cm length of 3” x 8” wooden planking right in the middle. It was still in excellent condition!

This is one of the two concrete castings, with the bolts and square nuts visible on the projection. This has had the backing mass of brick/cement broken away.

The casting had been removed and is resting on the scaffolding. the wooden plank is still embedded in the wall, with most of the backing rubble/cement broken off.

Here is the plank, with the residual rubble/cement still attached.

The upper end of the galvanised tube had been cemented shut at some point.

The tube was not in good shape.

So we will have quite a lot of blockwork and walling to re-construct, but at least the wall should be sound…

We initially put up two bays, knowing that we would (just) need a third.

Because the larger stones were mostly shallow, we only needed the chain hoist for the four heaviest. The rest we heaved down by hand.

We kept the area clear by stacking the stones where they will be needed for the re-build and barrowing the broken lime mortar to our hardcore pile.

This is where we dumped most of the broken lime mortar.

Most of the wall was fairly easy going. the last metre or two on the right were much more of problem, because of the damage from the concrete/cement.

Here is the second concrete casting and the steel tube, still in place. What is not obvious if the mass of rubble/cement behind and the damage to the original walling.

Almost done, using the breaker to get the last layer broken out.

Done and worth celebrating!

A large gap in our wall, just for two windows…

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.