Back to slating

Slating around the first rooflight 
We reached the first of our 15 rooflights, so we dug out one of our flashing kits, sat through a couple of YouTube clips and tried to make sense of the instruction leaflet. We had to cut slates to run them about 20 mm below the frame. This was going to be out of sight so I used the small angle grinder with a diamond blade. The bottom part of the flashing lapped over the slates and part way up the side of the frame to work as a soaker for the next course. We used the slate guillotine to trim the next five courses to size, fitting the soakers as we worked upwards. Our slates are quite chunky, so the top edge of the soakers were a bit above the top of the frame, we used the aero snips to trim the tops back. Next up we slid the covers up each side over the soakers onto the frame, screwed them down and fitted the top part of the flashing up against the top of the frame. That screwed in place and we cut the two courses of slate above the rooflight to lap onto the top flashing, 60mm or so from the frame. And that was it. It was slow but not difficult despite the instructions. 

• 

• 

• 

• 

Flashing the coping stones 
We started this section of roof against one of the gable ends with a raised parapet and coping stones. We had already cut a groove 30mm from the top of the stones, around 6mm wide and 25mm deep. Our rolls of code 3 lead were 240mm wide, enough to cut down the middle. We cut a 1.5m length, scored a line along with a Stanley knife, folded it back a few times and it split into two 120mm strips quite neatly. We lay the first strip over the edge of the workbench and used a rubber mallet to gently fold one long edge over on itself by 5mm. We cut away the end 75mm of the fold so there would be room to lap the next length of flashing into the groove in the coping. Then a second fold 25mm in, the other way down, leaving a skirt about 80mm deep. The lead was surprisingly soft and floppy, so needed carrying with both hands. We made up three lengths, more than enough to run from the base of the roof up to just short of the top. When we do the other side of the roof, we will finish the top courses on both sides, run a length of flashing right over the ridge and fit the ridge tiles over it. Back on the scaffolding, we gently tapped the 25mm lip on the first length into the groove in the coping and used a bolster to knock the folded edge against the back, raising it enough to lock it into place. We had trimmed the bottom end to 42 degrees, to fit against the top of the wall extension that is a feature of this corner of the east wing. To finish the job, we mixed a bucket of stiff dry mortar and pushed it into the groove to hold the flashing in place. 

• 

• 

• 

• 

• 

• 

• 

The rest of the roof
We made rapid progress once we were able to get a couple of full days in. We have moved two bays of scaffolding along, with less than two more to go. We have got the second, large, rooflight half-done after which it is simple slating right up to the north gable-end.

• 

• 

Finishing the fascia panelling

The only rough edges on our fascia panels were where the runs finish at the gable end. There are two on the north end and one on the south – the east run of fascia ends against the stub of wall that extends out from the gable end. Ric filled in the ends with bits of fascia board then cut covers from a sheet of aluminium. They wrap under the bottom of the fascia board as the panels do, but have flaps that fold round the right angle over the adjacent panel and over the top onto the sarking boards.

We coated and cooked them along with three joiners to cover where these covers lap over the panels. We coated them whilst it was raining heavily and whilst the primer went on well, the top coat was very unsatisfactory, with a lot of spots of primer showing through. We left them a couple of days and re-did them when it was warm and sunny, it all went much better and they were all fit to put up. It was a quick job to hook the covers over the bottom of the fascia board and nail through the top flap. Then we lifted the eaves trays out of the way and nailed the joiners across the join between cover and panel. Very neat.

• 

• 

• 

Screeding the north wing

We got the eastern end of the north wing ready for screeding whilst we worked on the east wing. We laid three loops of heating pipe for the kitchen area and one for the pantry. We did not lay pipe under the stairs or along the part of the north wall where we might put cupboard units. We put the second manifold between the kitchen and dining areas, between the fireplace and the north wall – this will be cupboard space. We pressure tested the four loops, with blanking pipes in the other 6 pairs of ports and had two of the compression fittings leak at 6 bars. We fixed this by using PTFE tape.

• 

• 

The rest of the north wing has been our workshop and has been quite cluttered with large and heavy items. We ended up clearing it out, finishing laying the insulation and mesh, installing and pressurising the underfloor heating pipe and screeding it as one (long) exercise, to be completed whist Ric is there.

Clearing the north wing
We cleared the small, loose stuff littering the floor easily enough and were left with the bigger items. We could not move stuff over the screed so everything had to go outside, across the courtyard and in through the big window. Each item was a challenge. The tables we carried between us. The aluminium folder we wheeled one end on our little trolley over scaffold board, The freezer housing we wheeled on the sack trolley at one end on scaffold planks. The washing machine and freezer fitted on the small trolley on scaffold boards. The woodworking machine was the challenge – we got it over the doorstep and across our pallet boardwalk on OSB laid on scaffold boards, then across the to window just on OSB. The run into the big window was too steep for us to push/pull, so we used our big orange ratchet straps wrapped around out external wall studwork and pulled it the last metre up and over the window sill. It was a miserable couple of hours, so we were more than glad to get it done.

Laying the last of the insulation
We laid the remaining full panels quite quickly and were left with a metre or so at the end and the area between the plant room and front door, which is where our pipes run. They all needed to surface in the plant room and it was quite complicated. We soldered the remaining lengths of 28mm copper pipe to the runs from the stove, ran them straight to the middle of the plant room, too a sharp left and brought them up against what will be the south wall, against the bottom of the stairs. We put a short length of 110mm brown pipe over the copper pipes to protect them from the screed. The cold water we ran over to the north wall, close to the rising main and both ends of the hot water loop next to the cold. The two pairs of feed/return pipes for the underfloor heating we pulled round to the east wall, mainly because they were a bit on the short side. They were a bit of a struggle to get anywhere near upright, so we left them at about 45 degrees. We filled in around the pipes with left-over chunks of board.

The services for the west wing we will run up the wall, through the joists to the upstairs en-suite then straight across the joists to the master bedroom en-suite. So we did not need to bury any additional pipes in the insulation, it was a case of taping all the joints and on with the next step.

• 

• 

Laying the mesh and heating pipe.
The mesh was easy, two sheets cover the width of the north wing with a bit of overlap and we covered the remaining floor with just over 4 sheets, including outside doorways. We cut the mesh for expansions joints in all internal doorways, at the west end of the dining area and the east end of the kitchen (to keep to the 8 linear metres/40 square metres limits).

We did the remaining heating pipework as 6 loops. Three for the dining room area, one for the entrance lobby and adjacent cloakroom, one for the utility room and one for the hallway between north and west wings. These joined the four existing loops at the manifold halfway down the north wing.

Pressure testing was trouble-free, although filling 10 loops with air to 6 bars was a bit of a struggle for our little 6-litre compressor.

• 

• 

• 

• 

• 

Screeding
We split the screeding into four blocks. Timing was down to a) the availability of the hire bull float, b) us all being around all day and c) the weather being dry enough to mix screed.

Session one was small – the section between the east wing and the kitchen area, around 8 square metres.

Session two was the kitchen area down to the fireplace, 40 square metres.

• 

• 

Session three was the dining room area from the fireplace down to the utility room/cloakroom, 40 square metres.

• 

• 

• 

Session four was the rest of the north wing up to the junction of the west wing.

• 

• 

• 

We were nominally laying 65mm  of screed, in practice the depth was often nearer 80-90mm, so we used quite a bit more screed. However, we ended up at the from door only mm out from the planned level, so we were right – it was the slab that was wonky, not our laying. We were knackered by the end and it will take a while to sink in that we can get going building the inside of the steading as soon as we get the slating finished. The inside already sounds rather more like empty rooms than a building site – a bit echoey.

Screeding the east wing

With the floor insulated and with the under floor heating pipes installed on mesh and pressure-tested, we were ready to screed the floor. We used a sand cement screed in the proportions of 1 part cement, 2 parts sharp sand and 2 parts quarry dust. We mixed it to a consistency where it would ball in the hand and break cleanly when pulled apart – not too sticky and not too dry. It was nonetheless quite dry and it really clagged up the mixer. We ended up scraping the barrel (literally) after a couple of mixes and giving it a good wash down every load. It took quite a few mixes to get the right consistency, when we did we speeded up significantly. An over-dry mix would not level properly and had a rough finish. An over-wet mix stuck to the float and was hard to get level. 

We barrowed the mix up and over the big window sill on scaffold planks, supported inside on small blocks of wood to keep the boards clear of the pipes. 

We did not use boards to mark out tramlines and use a board across the top to level the screed, the most popular technique on YouTube. Instead, Ric created small heaps, or spots, up to a metre apart. He used a float to flatten them down and a spirit level to get them all on the same level. These quickly became solid enough to use to work screed around them, using the spirit level to scrape out the high points. I was sceptical that i would be able to work accurately enough to help out, to my surprise it worked, and very well. It was accurate enough to be able to triangulate reliably enough between points to keep the surface level across the length and breath of the area. We dumped barrow loads of screed at a time between the spots, used a rake to spread it and either used an offcut of timber or our feet to tamp it down between and under the pipes. Then it was down to using a float and spirit level to smooth it out. Once we had a big enough area done, we used a hire bull float to smooth out the surface. It did a reasonable job, but we could have done with something rather heavier. 

The floor area is around 50 square metres, so we needed to worry about cracking due to expansion. This is a particular concern in tiled areas like the bathroom and kitchen. The guidance is to put expansion strips every 8 linear metres and every 40 square metres. So we ran a strip across the width of the east wing, between the second bedroom and the lounge at the south end. We cut a 65mm strip of 25mm insulation and sawed it down the middle. Where it crossed pipes, we cut notches on the strip and put a sleeving of polythene pipe insulation on the pipes either side of the foam strip. For good measure we also put expansion strips across all the doorways. 

Day 1
On day one we got the north bedroom, understair cupboard, bathroom and the connecting corridor done as far as the outside door. There was a lot of fiddling around and it was relatively slow. Ric did an excellent job around the pipes coming out of the floor to the manifold, including the 22mm pipes for hot and cold water and the flow & return for the heating. 

The trickiest area was the bathroom. This is to be a wet room, so we needed a surface that would drain water off the floor into the shower area. We had already cut out the insulation in the shower area, trimmed 25mm of the bottom and fixed it back. Ric worked it so that the door was level with the corridor but dropped slightly into the room. The floor was raised more at the edges in the corners and had very gentle slopes down to the middle of the room, then to the shower drain. The finish was a little rough because it was slow work and started to go off, however we are tiling it. It was a big relief to get a tricky job behind us.

• 

• 

• 

Day 2
Day 2 left us more than half the area to cover, but it was open so was faster going. We had interruptions because of heavy showers and a required visit to Peterhead, so we worked until 10:40pm to finish it.
We used the car headlights to light up the mixer and had bought two worklights for where we were screeding. We need the latter more generally as we race towards autumn and have the prospect of a waterproof roof. 

• 

• 

Underfloor Heating II

We finished laying the heating pipes in the east wing and went on to the first half of the north wing, from the east wing opening down to the fireplace. This is mostly kitchen/family room, separated from the east wing by a small pantry, the bottom half of the east wing stairs and a short corridor running into the east wing.

We do not plan to heat the pantry, but laid a tiny loop of heating pipe, for frost protection. All north wing loops are to head back to what will be a cupboard behind our fireplace, that will house the second of three manifolds. We ran the pantry loop hard up against the north wall where we expect to have a run of kitchen units, to minimise clod spots on the kitchen floor. We did the kitchen proper as one zone of three loops. As with the lounge in the east wing, we ran the first loop as a spiral, tying down flow and return ends together on adjacent mesh wires, but leaving 4 wires free within the spiral. We ran it into the doorway between the kitchen and dining room, the doorway to the courtyard and the corridor at the foot of the stairs, but not under what will be kitchen units. The loop ran out just short of the middle of the room. We ran the second loop in the same way, on two of the four wires we had left in the first spiral. It filled in the doorways and corridor, reached the end of the first loop and we started filling the space left in the middle until it too ran out. The third loop we ran from one end only on one of the remaining pair of wires, reaching the middle after a quite short run, because there were no odd areas to fill. We finished the middle of the floor and ran the pipe back out on the last free wire, using only 75m of pipe. So we have four pairs of pipe ends between the fireplace and the wall. The remaining loops will be for the lounge (four), one shared one for the utility room, lobby and cloakroom and one for the corridor to the west wing.

• 

• 

Meanwhile, we mounted one of our manifolds in the east wing under-stair cupboard, then spent a couple of hours trimming the ends of the loops to the correct length and fitting them into matching flow and return ports on the manifold, using the oddly-named eurocones, which are compression fittings. Five of the pairs of ports will not be used until we get the upstairs heating pipes laid, we used short lengths of spare tube to fill them in so we can pressure test the pipes we have laid. We closed off the valves that will connect the circulation pump and thermostatic mixing valve into the manifold. We closed off the automatic air bleed valves at the other end of the manifold and used a ¾” port on the feed side of the manifold to temporarily fit our 10-bar pressure gauge. We fitted a washing machine hose to the equivalent port on the return half and the other end of that into our compresser air line. We opened all the loops, then used the compressor to pressurise the whole lot to 2 bars. We fixed one air leak and carried on to 4, then 6, bars. We closed off the air filling port and left it overnight. It was, somewhat to my surprise, still exactly at 6 bars pressure, so passed the test. We left it pressurised as we screeded the east wing.

Starting with the slating

Ric has started us working on slating. We will cover the east side of the east wing roof, since this runs between copings at each end, with no valleys.

As with most things in life, there is a lot of preparation. There has been the weeks of work sorting the slates into weight categories. Ric worked out the spacings we needed between courses, including the two starter rows that are hidden below the first visible course. The slates are around 465mm long and 230mm wide, we will have a headlap of 190mm and the bottom two courses will be ?? and ??mm long respectively. We made up a suitably large set square, attaching batten to our aluminium square. We used this to mark a vertical line up close to the coping, to find out where the coping was furthest from the line. This is where a whole width slate would be used, all others above/below would need trimming to size. The bottom-most slates needed special treatment because that is where the coping runs down onto the extension walling rather than a simple retaining stone. Ric cut a right-angled notch out of the first and third slates.

We agreed that the first five courses would use the heavy, thicker slates, then mediums for most of the roof, then a couple of courses of the light ones. The lowest course is nailed on upside down, with the second course right way up and lined up with the bottom of the first, 50mm beyond the edge of the eaves tray. The third, full length course also lined up with the bottom edge and it was then the 190mm intervals upwards with full-sized slates. We cut slates for the start of each row, to fit the space and avoiding having less than 150mm width. Cue the slate & halves that we got from the Slate Centre. The slate cutter was pretty good, though Ric reckoned it was not as good as his smaller one. I was able to cut the length of the slate & halves in two goes and across in one. We used the Hambleside Danelaw plastic soakers up against the parapet, just hidden under each slate and fixed to the sarking with a single nail. They did partly cover the slot for the flashing in the coping, Ric suggested we use the angle grinder to cut them out of the way before we fit the flashing. Where the nail holes were either too high up the slates or too low so that they were over the previous course, we found we could drill holes easily using the drill driver with a 4mm masonry bit.

I struggled early on with vertical alignment of the slates, getting successive courses exactly half a slate on from the row below. I had marked lines at 190mm across the bit of roof I was working on, I will also put vertical lines at intervals to check on the alignment. The other problem I had was that the bottom row had spacing between slates, but it ended up being squeezed out on the courses above. By the end of the first day, I had seven visible courses with the bottom row being 10 slates long. This will just about let me get up to the ridge, although we will leave the topmost ones to do from the other side, so we do not need to rest the roof ladder directly on slates. Collectively the slates looked good, even if they are a bit rough in detail (they are).

• 

• 

• 

Underfloor Heating

We have bought two underfloor heating kits online. They each comprise a 10-port manifold, pump, valves and fittings and 10 x 100m rolls of 16mm PEX-Al-PEX barrier pipe. The latter has a middle layer of aluminium that means the pipe can be straightened and bent and will hold it shape, a property that we quickly appreciated.

There are dozens of suppliers, offering pretty much the same sort of thing. We chose ours because they did not include the stuff we do not need, especially the plastic clips that many people use to fix the pipes to the insulation. We are going to use 3mm wire mesh on a 100mm repeat (it is called wrapping mesh) instead and will use our existing bundle of wire ties to tie the pipes to the mesh. There are two benefits to using the mesh: It helps distribute the heat more quickly & evenly and it will make it much easier to plan and route the pipes. We are using a heat pump that will deliver water at 35c, so will use a 100mm pipe spacing rather than the normal 200mm. Because the pipe does not really like turns as sharp at 100mm, we will not loop the pipe side-to-side across and along the room, but lay the pipe in a spiral at 200mm intervals. When the pipe reaches the middle of the room, it has space to turn round and out, filling in the gap left by the pipe spiralling inwards. This does not require turns tighter than 200mm. It also has the benefit of evening out floor temperatures because hotter incoming water I running alongside cooler outgoing water. Having the mesh will really help get us clean, simple pipe runs – a bit like a dot-to-dot puzzle.

We got the mesh in the east wing laid and joined together with ties, then used a spray can of paint to mark our walls, doors and areas that do not need heating – wardrobes and, when we get into the north wing, kitchen cupboard units.

Then down to designing the pipe runs. A 100m roll of pipe will nominally cover 10 square metres of floor, less any pipe used running from the manifold to the room. In the east wing, the two bedrooms and bathroom will each use a single circuit, the public room at the far end will need two and the corridor will largely be filled out by the pipes running to and from the other rooms. We have an external coil pipe bender to make the corners in the pipe, but will see whether we need to get a proper bender.

When we got going with the pipe, it turned out to be quite manageable. We unrolled the pipe, straightened it and made the bends at corners, then used the wire ties and twizzler to fix the pipe down. It was all exactly as I had visualised it and was quite well behaved. For the public room (currently named the Room of Requirement), which used two loops of pipe, we opened out a roll of pipe for the first loop and ran both ends together from the manifold area in a spiral that left room for the second loop to go out and back. When the first loop was finished i.e. around the halfway length, we tied that down and ran the second loop in the space left by the first and filled up the area inside that the first loop did not reach. We even had enough pipe left over to cover the corridor leading from the understair cupboard to the Room of Requirement. We used exactly the full 200m of pipe, with none spare, it was a very close-run thing. Without thinking, I ran the external pipe bender along one end of the first loop, got to the middle of the length and only then realised that, having tied both ends of the pipe down as we worked our way in, there was no way to get it off the pipe. I had to destroy it by unwinding it, a beastly job. I will not replace it, the pipe is easy enough to bend safely without a bender.

• 

• 

• 

• 

• 

We have more to do once the pipe is laid and tied down. We need to lift the mesh by 10-15mm so that the pipes are in the middle on the screed, not the bottom. We need to pressure test the heating circuits before we lay the screed. For the latter, we have ordered a 10-bar pressure gauge that will fit temporarily onto the manifolds using a standard ¾” connector. We will use the compressor to pump air via a washing machine water pipe (also ¾”) into another connection on the manifold. We will pump the circuits up to 6 bars and leave them for several days to ensure they do not leak.

Floor insulation in east and north wings

We are well through laying our floor insulation in the east and north wings. Our building warrant calls for 100mm PIR foam panels over the floor, with a 25mm PIR foam upstand around the edges, to the height of the screed that will cover the panels. Because much of our upstand will be against studwork and will be unsupported in the gaps between studs, we planned to lay 6mm plywood outside the foam. So we ordered from Ellon Timber and duly received large bundles of 100mm Quinntherm, a smaller bundle of 25mm QuinnTherm and a much more modest pile of plywood. We had a session cutting up the 25mm panels into 165mm strips (100mm insulation plus 65mm screed), using the jigsaw to slice three panels at a time. Then a session cutting the plywood using the circular saw.

• 

• 

• 

• 

We got the upstand & supporting plywood installed ahead of time, using aluminium tape to join the foam strips. Laying the panels was not particularly demanding because most of our floor space is rectangular. We had to do a bit of sawing to fit panels into the understair cupboard, around the fireplace and into doorways, otherwise it was whole panels. We worked our way through several cans of squirty foam filling in gaps. What did take the time was taping the boards together (aluminium tape again) and running service pipes through the insulation.

• 

• 

• 

• 

We installed a hot water loop using 22mm polybutylene pipe. The feed pipe surfaces at all points we need hot water taps – Cloakroom, kitchen, understair cupboard (to go upstairs to the east wing en-suite) and family bathroom (the furthest point) – so that we do not have connectors out of site below the screed. The return goes all the way from the bathroom back to the plant room that will hold our thermal store. We ran a cold water feed along the same route, again with 22mm plastic pipe. We laid two pairs of 22mm plastic pipe to where we will install heating manifolds – the east wing understair cupboard and a cupboard halfway down the north wing, adjacent to our fireplace. We ran the pipes in channels that had 25mm insulation above and below and insulation upstands to separate the pipes. We bundled the hot water feed and return into one channel, because they will run at the same temperature. We also ran the two feeds for manifolds together and the two returns together because ordinarily they will also run at similar temperatures. We used exactly four x 50m rolls of pipe. The advantage of the polybutylene pipe, over PEX for example, is that once uncoiled, it did lie quite flat and straight. It was a bit of a beast to run round corners and to get it above floor level though. We routed the pipes to have the fewest possible corners, all the way up the north wing close to the north wall, then 90 degrees right to get to the walkway through to the east wing, 180 degrees round into the understair cupboard, straight out of the understair cupboard along the east wing corridor and a 90 degree left turn into the family bathroom.

• 

• 

• 

• 

• 

• 

Two additional pipes will run from our stove back to the plant room and will be 28mm copper. We have no option but to solder together the 3m lengths with straight connectors and use elbows to get the pipes into the fireplace and out of the floor in the plant room. We are about three-quarters of the way through laying the insulation. We have done all the tricky bits, but do need to clear the north wing of the work tables I made, the woodworking machine, aluminium bender and the freezer/washing machine housing, so we can finish the job.