We hired a digger and dumper from Ellon Timber, to sieve and remove spoil from out courtyard. We borrowed the dumper at intervals to run loads of our hardcore up our driveway, patching up potholes. Ric sieved four loads for us, for shallow repairs and we used un-sieved for the deeper potholes. They all got compacted down for several days before we had a day of rain. I was a bit surprised that it had all locked down well and even survived an Ellon Timber truck delivering timber and rooflights to us. Some of the repairs were rough, but definitely better than bouncing around through the potholes. We need at least another 8 loads to finish tidying it up. It is a temporary fix until we can afford to get George to use his big digger to break up the current surface, add in more hardcore, then roller it down for a permanent fix.
Tag Archives: Hardcore
Creating the floor slab – I
We pushed on with our main priority – getting a concrete floor slab in place. A job of many layers…
First, clean up the excavation
We squared up the excavation, clearing bits by hand that the digger could not get to – this was quick, a few hours and barrow-loads for the whole floor area. I spread the trimmings across some of the low areas. We temporarily removed most of the drain pipe we had placed the year before, to make access easier and avoid damaging the pipes. We left the drain for the cloakroom area in the north wing, because it only stuck out by a metre or so, and the deep drain in the bathroom area in the west wing, because it was still (just) buried in the subsoil.
1 – Hardcore
Next up was the 200mm layer of hardcore. We started in the garage area because it was easy access and small. It would also let us access the master bedroom area beyond. Ric used the digger to load the dumper and drop the hardcore in the area we were working. I spread and levelled the hardcore, working from the back of the area towards the entrance. The hardcore is brutal stuff and was a pain to work with. It includes hefty lumps of broken concrete/stone up to 15cm long and the matrix looked like a mix of smaller broken concrete/stone and quarry dust. The big stones seemed to ‘float’ to the surface when dropped from the dumper, I spent a disproportionate amount of time and energy shovelling or throwing them by hand into the un-filled areas. I spread it by eye, trying to get it 5cm or so above the compacted level we needed. It got easier with a bit of practice, eventually I had no problem getting a decent regular surface with no more that 3-4 cm difference in height over the area. We filled the area then used the wacker plate to compact it. That worked a treat. After four runs – along, across, along and across – it compacted down the expected 50mm and had all locked solid.
We built a ramp of hardcore to get the dumper truck in and out – 6 dumper loads. We left the long sides clear of hardcore to form troughs along the edges, about 50cm wide at the top and 20cm at the bottom. These will fill with concrete, to thicken the slab as per the architects design – to support the structural timberwork that will hold our floor joists up. We did not bother in the places we had already laid foundations, these will support the slab directly. We cleared the hardcore ramp into a space we had left, compacted the whole lot and that was job done. We put the pipes back in and had to use pickaxes to break up the compacted hardcore, a couple of hours of hard labour. Lesson learnt – we will put the pipes back in place before compacting!
The following day, Ric built hardcore ramps to get access to the long north wing and the east wing. Then it was a lot more of the same – empty a dumper-load, pick out the big stones on the surface and drop them out of harms way, level with a shovel and, when the area was filled, compact it.
In the north wing we needed to complete the pipe that will feed air to our woodburner – I had run the pipe under the wall from the outside but could not finish it because there was a pile of spoil inside. Ric had uncovered the end of it when he excavated the subsoil out, it projected about 50mm into the floor space so that it will be easy to get at, to finish off. I waited until we got the run of hardcore right up to the pipework, connected a pipe to halfway across the floor and put an upright on the end of that. We dumped the next loads of hardcore right on top of the pipe, then carried on as normal.
In the east wing, we left the long edges clear of hardcore, to form the troughs for thickening the floor slab, just as we did at the west end.
After three days work, we had all 230 square metres covered in hardcore and compacted. We had used 110 of our 180 tonnes of hardcore, more that I estimated, but we are not short of the stuff. I guess we had over-dug some areas e.g. because of obstructions.
Floor slabs
We did the garage area first, it is a bit rough because of the large stones on the top.
We ran this ramp from the garage area to the master bedroom area.
We used a broken scaffold board for the run up
Adn another load makes its way.
We levelled out the ramp at the end.
We got a flatter surface this time around.
We used a pick-axe to re-lay the drain pipes – slow work
We are making inroads into our hardcore piles!
In the long run in the north wing, the cloakroom drain pipe is currently above the base level and will just be covered by the hardcore
The drain is safely under hardcore
We put pea gravel around the drain pipes
We got teh best finish so far…
And this is the wacker, amazingly effective.
The last area to do, the east wing.
Annoyingly, this pipe is partyl above hardcore level.
And the last of the wacker-work!
2 – Running services through the floor slab
We had already laid two armoured electrical cables, originating in the plant room area, near the future front door. They both run through the master bedroom area and into the south run of drain trenches. One is for the bothy and diverts off and (temporarily) above ground under the caravan. The second carries on all the way beyond the septic tank, where it will power the pump for our raised drainage mound. We have also laid a 20mm blue water pipe alongside the cable that runs to the bothy. It too starts its journey in the plant room, where the rising main will appear above concrete. This pipe is in use as our temporary water supply to the caravan, we will run the pipe and cable into the bothy once the caravan is finished with.
We want to lay a third electrical cable, for our polytunnel. It will run from the plant room, along the full length of the north wing and across the west wing to our family bathroom area, where it needs to exit the building on the east side through the foundation opening. We are burying all the cables and the pipe in the blinding layer, above the hardcore and below the damp proof membrane.
We did one other job at this point, testing the reinstated drains for leaks. We bunged up one end of each pipe at the inspection chamber, filled the pipe with water and left it for ages to see if the level dropped. They did not, they all passed with flying colours.
The electric cable for the polytunnel is laid on the hardcore before the blinding.
The water supply and the three power cables all in place in what will be the power room.
3 – Blinding
The 50mm of blinding helps level the surface and protects the damp proof membrane from being punctured by stones in the hardcore. On advice from our builders merchants, we got 20 tonnes of quarry dust delivered. This is more gritty than the sand I was expecting to use and compacts well. Plus it is half the cost. We divided the floor area up into equal-sized segments and put a dumper-load – a tonne or so – in each segment. We raked it out roughly level then used a home-made screeding rake to level it out and compact it. This was one of our short, fat, kwikstage scaffold boards on its side, with a handle attached. We even put a spirit level on it to work out when the blinding was levelled. The tool was surprisingly solid and heavy and using it was hard and slow work, but after enough runs across at different angles, it produced a very flat, compact, smooth finish. We finished off with a single run of the wacker plate for good measure. We used a couple of extra dumper loads to line the edges and bases of the troughs we had left in the east and west wings. The three electricity cables and one water pipe were duly buried. They all come up together out of the blinding, cable-tied together, in a corner of the plant room area.
We spread the piles of quarry dust evenly over the hardcore
We got a pretty good level surface.
We did a single run with the wacker.
It was a comparatively quick and easy job.
The east wing was slower to sort out because of the foundation blockwork and the drain pipes.
We lined the troughs at teh sides of the east and west wings (to thicken the floor slabs).
This is our screed rake, made from a scaffold board. Note the spirit level!
The most troublesome area…
4 – Expansion joint
We are required to put an isolation joint round the perimeters of all the slabs, to accommodate expansion of the slab. I used 13mm bitumen board, which is a soft fibreboard that I could cut with a Stanley knife, but which went quite floppy in the rain. I cut the boards into strips – 17cm wide (7 per board) for most of the perimeter and 40cm (3 per board) in the troughs. It was my least-favourite job to date – slow and too much bending, standing & kneeling. We ran the board into our doorways and the various nooks & crannies in our walls. The positive in all this is that the damp proof membrane will be protected from sharp edges in our walls.
The strips of expansion board in teh troughs were 40cm deep.
Elsewhere they were 17-18cm.
5 – Damp Proof Membrane (DPM)
We used 1200 gauge (300 micron) polythene DPM in standard 4m x 25m rolls. We always worked across the floor area between outside walls, using PVC single-sided tape to seal the 400mm overlaps. We did not bother with the double-sided tape we had planned to use. The open areas were easy. Where we had a pipe coming up, we cut a slit, dropped the membrane over the pipe, then cut a small square of membrane that we cut accurately to the diameter of the pipe, slid down and securely taped to both pipe and membrane. It was a lot more tricky sorting out the various door recesses and the troughs. We had to cut and patch it a lot – a sort of giant craft activity. The tape was very effective, even on damp membrane, but was not so good when rain puddled up. I also found by experience that DPM is not the thing to do on a breezy day – at one point I had to give up and wait until the wind died away.
A slow start!
We used a couple of sheets of mesh to stop the DPM being blown around. We overlapps the lengths of DPM by c. 40cm.
We cut out sqaures of membrane to push down over drain uprights, then taped then securely in place.
Most of the garage area was covered in one length of membrane!
We ran the DPM up onto the foundation blocks and taped them down.
6 – Reinforcing mesh
The last job before we got the concrete mixers in was to lay the reinforcing mesh. We used 8mm A252 panels 3.6m x 2m on 70mm supports. This in theory gives us at least the required 25mm of cover over the mesh, even where the mesh panels overlap. We made slow and steady progress, working through a handful of 9” angle-grinder disks cutting the panels to allow for pipes and recesses. Moving the panels into place was definitely a two-person job, it was too easy to catch the membrane and make holes in it. We overlapped the panels by 30cm and wired them together – using a twizzler device to wind the wires and tighten them. It was all solid enough to walk on. The most awkward bit was where one of our pipes gradually sloped up above the blinding and up to mesh height. I cut out a couple of small panels of mesh and used a sledge hammer to form them into curved up-stands that went over the pipe and were tied to the mesh either side. Hopefully there will be enough depth of concrete that they will be covered!
The mesh is in place in the west wing…
We used teh angle grinder to cut the mesh and wired the sheets together with a 30cm overlap.
The long run in the north wing, ready for concrete.
The west end ready as well.
I used a sledge hammer to bend this sheet of mesh over the raised drain pipe.
We hung mesh down into the troughs to further reinforce them.
Tidying loose ends
I was in Aberdeen for 8 working days near the start of July, to clear the decks before getting our floor slab laid in August/September.
Catching up with progress: Ric had got a lot done after we headed back south.
The monumental task of clearing the courtyard is well under way.
A large chunk of the courtyard cleared and levelled.
Almost all cleared!
The soil screener is remakably effective, separating concrete & stones from spoil.
This is our uncrushed concrete pile.
This is the hardcore that replaced much of our concrete pile.
In the background, the screened spoil is being re-distibuted.
Complete the gable-end foundation
Ric had time on his last visit to lay the missing foundation for the north-west gable-end wall. I was to do the blockwork and associated concreting. The foundation is rather complicated. It includes:
- The foundation for the gable-end proper, to support the wall to one side of the future garage door. This is two leaves of blockwork, 50cm wide and some 2m long.
- The foundation of the adjoining wall on the single storey section, also two leaves of blockwork. This is set back 22cm relative to the gable-end and is about 1m long
- Tying this foundation into the Front door foundation, which is single leaf blockwork.
- The back of the gable-end foundation tying into the internal foundation that is to bear the structural timberwork for the floor joists, roof trusses, stairs and garage wall.
I measured up from as many reference points as possible, marked out the lines to follow and got going. As usual with working below ground level, I used a 1:4 mortar with plasticiser. I got the first two courses in place and filled the section with two leaves with 1:8 weak concrete. Next day I did the two remaining courses, thickening the mortar to get the required height. Because I am not sure of the finished ground level, I left the outer leaf at the same height as the inner one, I will raise it later if needed. I ran the gable-end blockwork along the full run of the foundation, it may need trimming back when we sort out the garage door, depending on what size opening we need. Anyway, it was then straightforward to run the front door and internal foundation blockwork to meet the new blockwork. Two days of effort in total.
Two courses of blocks in place.
Up to full height, four courses of blocks.
On the left is the missing wall onteh north wing, running up to the front door. On the right is the gable-end foundation running up to the garage wall.
The gable-end foundation blockwork filled with weak concrete.
The north wing foundation filled as well.
Bridging the gap between the front door foundation blockwork and the new foundation.
The foundations all joined together frpm front door to garage door.
The internal foundationthat will support our garage wall, the roof and the stairs is also connected. It needs some reconstructive surgery itself, when we get round to floor slabs.
Run an air pipe for our woodburner into the steading
Our woodburner will be used during the colder months to 1) heat hot water and 2) power the underfloor heating, supplemented by the air-sourced heat pump.
The warrant specifies an 18kW Boru Carraig Mor double-sided stove model (i.e. has glass-faced doors both sides). We did say in our conversation with the architect that we would be interested in a double-sided stove, located between the kitchen/family room and the lounge/dining room, so that we could heat both directly. However, double-sided boiler stoves are a rarity, probably for good technical reasons. We have struggled to find good reviews of this model, it is not particularly efficient (73%) and Boru stoves in general do not seem to be well rated. We will pass on it and find a higher-efficiency, better rated model. A plus for it is that it puts 13kW into water and 4kW into the rooms. With our levels of insulation that is probably about the right ratio. The majority of boiler stoves put less into water and more into the room, so we will still be quite restricted in our choices.
Whatever we decide on, we need to provide it with a source of air from outside. We decided to run 110mm pipe down then under the north wall, up into the hardcore under the slab and run an upright through the slab. The outside upright will need a cover of some sort to keep water and animals out.
I could not do the whole job because of a big pile of spoil on the inside of the wall. I dug down on the outside, then under the wall to as much over 50cm length as possible, so that the pipe would stick out the other side when we got the inside excavated. I cast a 200mm slab of strong concrete under the wall, put 100mm concrete block each side and five sections of 100mm x 50mm lintel across the blocks. For the last three lintels, I rammed dry-ish mortar up to the base of the wall, I will sort out the first two from the other side of the wall later. We were concerned about water getting into the pipework, so I dug a channel downhill to the main drain running conveniently close by and filled it with pea gravel.
I used slotted drainage pipe for the horizontal under the wall, to stop water accumulating in the pipework, the rest is to be brown pipe. I filled up the area around the pipe to lintel level with pea gravel, then covered with spoil. Less than a day of effort in total.
Hole dug down and under the steading wall from the outside.
I broke through into the surface water drain, you can see the gravel.
The concrete pad is in place below the wall.
Gravel in place to allow water to soak back into teh surface water drain.
The blockwork and lintels went in on the pad, the slotted horizontal and brown upright pipes are in place, with gravel around teh upright and spoil elsewhere.
The hole backfilled with gravel and spoil to above lintel height.
And all levelled up to finished surface.
Cap the wall heads with mortar
Back around Easter time, I got one wall covered in a layer of 1:4 mortar. This is to protect the wall head from rain soaking down into the core of the wall and freeze/thaw damaging the structure. It also provides a flat surface to lay the blockwork that will raise our roof by the 40cm specified by the warrant – to give us enough headroom in both upper and lower floors. I even got some of the blockwork in place, but had to abandon work on it because of other priorities – demolishing the gable-end wall and filling the soakaway, as I recall.
On this visit, I needed to get the remaining wall heads protected with mortar, though I knew I would not have time for the blockwork, which we cannot complete anyway without all our lintels in place.
I started on the south wall of the north section (single-storey), then did the higher walls in the west, then east sections. It took seven builds of one- or two-bays of scaffolding to get the job done – much of the time taken was constructing and dismantling, relatively little was mixing and applying the mortar. The south wall was in poor-ish condition and needed some reconstruction before laying the mortar. The others were in much better condition and quicker to sort out.
I mixed a barrow of mortar at a time and used a large flexible builders bucket to get the mortar up the scaffolding. I then poured the mortar onto the wall heads and spread it using a bricklayers trowel. I got the mortar horizontal across and along the wall to within 5mm or so using a spirit level for close-up and a scaffolding plank for the overall levels, then moved on. The whole thing was quicker and easier than I expected. Two days effort in total.
At the start…
The north wing walls need quite a bit of patching up.
This is where the roof has shed water onto the wallhead and damaged the lime mortar.
Cement mortar laid with no more than 10mm variation in height.
Now moving to the west wing.
The west wing wallheads are in disctinctly better condition than the north wing walls.
This teh north win with blockwork on one side and the new capping on the other.
Weeding
This was not planned. From a full clean out in April, our fencing, hedging, orchard and shrubby area was inundated with perennial weeds – mostly sow & common thistles, cotton (Scots) thistles, nettles, grasses, goosegrass and docks. Most were getting ready to flower, but had not done so, so I figured they could be safely composted.
I hand weeded the areas with plants we wanted to keep – all the areas with weed membrane and woodchip mulch. I made several useful observations: 1) the woodchip mulch is starting to break down and compost, meaning weeds are starting to take root above the membrane, 2) grasses creep over the edges of the weed membrane and grow roots through into the soil below, 3) many of the thistles are finding the slits in the weed membrane, pulling them up is easy and brings large amounts of horizontal tap root with them and 4) the stones we use to hold the membrane in place accumulate enough soil to allow weed seeds to germinate.
The rest of the plot I could & did strim. Our strimmer, a Stihl FS-40, is a brilliant, very capable, piece of kit which takes 2mm line. It excites our dog wonderfully. It is too light for the mature docks and cotton thistles, I used a spade to slash these off at ground level. I do need to look around for a better-designed slashing tool.
The north run of hedging + weeds.
The east run of hedging + weeds.
The south-east corner was particularly overgrown.
The fields outside the fence were overgrown.
Field boundaries sorted!
Weeded on teh left side, unweeded on the right!
I broughtthis Acer up with me and planted it in place of a deceased schrub.
Our shrubby patch needed tidying up.
Our rochard-to-be was also getting drowned by weeds.
This Bramley has fruit on it!
One of my more impressive barrow-loads of weeds.
Adn teh compost heaps were full!
All looking much better.
This is one of our copper beech trees.
Spare time
Unusually, I finished ahead of schedule. I had a full day to do the odd jobs that had been lurking in the background. Amongst other things, I tidied the bothy and hung loads of hooks, to store shovels etc..
Hooks to hang most of our building tools, plus the strimmer.
It may not look so, but this has been majorly cleaned up!
Tidying up
Most of our concrete pile has gone, we have hardcore. Lots of it!
George eventually contacted us to say that he had found someone who would deliver crushed concrete for £8.50 per tonne and take away our waste. He arranged a day, arrived with his digger and over the day got 10 truckloads loaded. A sort of downside was that the crushed concrete was more compact than the broken concrete, so around 19 tonnes arrived for every 15 tonnes taken away. We still have a big pile of broken concrete.
So we have plenty of hardcore – 186 tonnes of it. My rough calculation is that we have around 240 square metres of hardcore to lay, to a minimum depth of 150mm = 36 cubic metres compacted. So the uncompacted volume will be 40+, a bit less than half our pile.
Taking the remaining pile of broken concrete and the large areas of hardstanding round the north and east sides of the steading building, I expect we have converted about half our concrete to hardcore.
Ric reckons the hardcore is good for the floor slab, but a bit coarse for dumping on the track. He did talk about it with George, who said that he could use a digger to lift the existing track surface, incorporate the hardcore and get it compacted. Our track is some 450m long, the section nearest the road and shared with West Byreleask Steading is in good condition, so we would need around 375m sorting out. If it is 3m wide, that is 1125 square metres. Adding 120mm hardcore would use 140 cubic metres, just about what we would have after a second exchange for crushed concrete. George thought it would take a couple of days to sort the 100m stretch of track that is used by George Senior (our neighbouring farmer) and which is getting rather rutted.
The trucks made a mess of the concrete on the hardstanding between the concrete and the driveway. I expect this will get worse as we get concrete mixers on site for the floor slabs.
Our concrete pile is a lot smaller than it was, but still disappointingly big.
However, this is what 186 tonnes of hardcore look like.
Landscaping
Disposing of the spoil that we have generated over the last two years has been a challenge. Most of it, Ric has screened. This is slow and boring, 30 tonnes or so per day, but very effective. Ric piled the separated stones/concrete ready for us to sort through. He put the topsoil to one side. Once he had leveled up the area leading to our raised drainage mound, and cleared the courtyard of rubble, he put a whole load of screened subsoil back into the courtyard and leveled that up to a safe distance below DPC level on the foundation blockwork.
In sorting the courtyard, he uncovered a run of salt-glazed clay pipes heading from the steading towards the concrete tank. There is a lateral running off part way down. It looks as though they may have connected to a similar pipe we uncovered when we dug out the door foundations last year, in which case we should find more when we scrape down the internal floor to below slab level.
He had cleared the loose material in the north leg of the steading, broke and removed the concrete and scraped & screened the cobbles just under the concrete. He ran out of time to excavate down to floor slab level.
The soil screener played a heroic role in the big tidy-up!
In the mid-ground was the foundations of a former wall.
This pipe headed to the concrete tank across the courtyard. One branch headed up to a doorway where we had uncovered more pipe. The other looks like it heads to the west wing.
Surface water drain just about complete: Having leveled up the courtyard , Ric jokingly said that it was larger than some building plots he has worked on. Then he dug into it to run the missing trenches up the east and west sides to the south-facing wall, ready for the downpipes that will drain the south-facing (single-storey) roof. He put junctions in, to get to the side walls, for downpipes for the east- and west-facing (2nd storey) sections of roof. He warned us that the pipes on the west side are shallow and will not bear vehicles crossing them – not likely to happen, anyway.
And that was it, apart from one missing link: Getting an extension to the north-west corner of the building for the very last downpipe. This needs to wait until we have dug up the track to divert one of our problem field drains and got the foundation for the demolished gable-end wall in place.
Unwelcome delays: The digger from Buchan Power Tools broke down twice, with burst hydraulic pipes. They were a bit iffy when the second one happened, but took the old one away and let us use a more-or-less brand new one – which was much better for what we wanted – lifting spoil into the dumper. I ordered materials from Ellon Timber to let Ric get on with something whilst he did not have the digger, they arrived way too late, minus a couple of essentials.
Ric just about ran out of diesel, arranged with George to fill the jerry cans and did not get them back for several days. Ric eventually cycled in to Ellon with two of our 5l cans and filled them, to let him get something done.
On the plus side, he was only rained off for a couple of hours. Generally he had sunny but cool weather.
Another unwanted drain: Just before he headed down to Cornwall, Ric dug out the foundationless area under the recently demolished gable end. He uncovered a glazed drain that runs at least 8m under the steading, probably much further down to the edge of our plot. It looks older than the steading, whilst the brick structure (that alerted Ric to a problem in the first place) was probably a more recent addition, to channel water into it when the silage pit was built. He is suggesting we could keep it as a drain, I doubt the architect would want that. Anyway, he dug out below the soft ground and laid a 200mm foundation slab with mesh. It butts up to the front door foundation but is a bit deeper. At least we know why the front door foundation flooded when we dug it out.
I still think this is where we heard running water when we first bought the property, it must still have been active. In which case, it may be the drain that the architect knew about and wanted us to divert. In which case the land drain we discovered under our foundations last year is a sort of unwelcome bonus.
This is the uncovered pipe, with a bit of tube in it to indicate where it runs.
Ric dug out soft ground to prepare teh new foundation for the gable-end.
He had time to lay the concrete and mesh. The rest will wait to next visit.
What next? We had not quite got as much done on our priorities, as we would have liked. I will aim to be back up for a week in July, whilst Jill is on holiday. I will do the blockwork for the new foundation and carry on with capping the walls.
Ric suggested I phone our youngest brother Geoff, to see if he could take a working break in September, to help get the floor slab laid – he had seen Geoff at work & felt he would make a good job of it. I phoned Geoff, he thought he could combine it with a holiday, in which case Ric would do another block of work, arriving a couple of weeks early to be sure that we got all the floors scraped down and cleared. That way, the two of us could barrow whilst Geoff finished the slab. Sounds like it might all be on to get a floor slab in this year. In which case roof trusses the following year would be a distant possibility.
East Byreleask Steading 
