Almost the last bit of our surface water drainage…

At the end of work last September, Ric extended the top of our north run of surface water drainage, past our new garage door opening and round the corner, to form the last gutter downpipe. He had thoughtfully included a socket to connect a linear drain across the front of our garage door opening and front door opening. We bought the drainage channels last year, bar a silt trap, which I ordered a week or two ago. As soon as the silt trap arrived, Ric dug out a shallow trench, laid a concrete foundation and installed the drainage channels. This leaves us in the position where we can go ahead and complete our driveway off the track into the garage door opening, including tying it in to the trackway. We will discuss it more once we are up there, we are still thinking about cobbling at least some of the area.

I had thought this was the end of the surface water drains, until Ric decided we would need to look at draining the courtyard – the pipework he put in last year is for gutter downpipes. He is, as usual, right.

Fixing minor flooding

Ric is in residence and is tackling several bits of unfinished business from last year, awaiting our arrival later in April. High in our thoughts was tackling a couple of areas of poor drainage. At Christmas, after a wet-ish early winter, we had standing pools of water at the south-west corner of our plot, slowly killing our hedging. This corner always has been marginal; immediately over the boundary into the next-door property, there is a patch which has had standing water on several of our visits. A second wet patch is at the north-west corner, immediately up from our driveway off the shared track. This has been a problem since we bought the property, is small, but is also killing the hedging.

After a wet winter, Ric confirmed that the flooding is a biggish deal, worse than at Christmas.

The other place that had standing water, when we bought the property, was the north-east corner, with water running off the field immediately to the north. As we suspected last year, this is no longer a problem, having squared up the boundary when we put our fence in. The whole east side is in fact slightly higher than the west side.

So Ric tackled what looked like the tougher nut to crack – the flooded south-west corner. He used the digger to cut an experimental trench, it promptly filled with water and he could not see what he was doing. He thought about if for a bit, then had a light bulb moment. He recalled that when scraping out the area where we plan build the drainage mound, he had dug out the top end of a field drain running downhill to the south. It was below a shallow ditch that ran alongside the extensive concrete ramp we inherited, now broken up. At the time, he had covered over the end of the drain and half-forgotten it. It was a quick job to dig a trench at right angles to this, parallel to our southern boundary, lay a couple of lengths of perforated pipe, tie them in to the field drain, cover in pea gravel and re-fill. This French drain started work immediately and after a day or so the flooding was no more. The field drain appears to be in excellent condition, with plenty of capacity.

Just about in the middle of the photo is the top end of the field drain that we dug out last year

This shows the junction of the perforated pipe and the field drain, before covering.

The junction of the perforated pipe and field drain has been covered with plastic.

The first of the pea gravel that completes the new French drain.

The north-west corner was a simpler job, that he had already prepared for. He ran a drain across our driveway last year, to intercept the field drains severed when our water supply went in. This continues to work very well. He had left a spare socket at the top end of this and had left it open. So he dug a short extension trench up to our boundary and tapped into the flooded area. With more perforated pipe and pea gravel, he got that fixed and re-filled.

We will wait until next winter and see if we have any further issues.

Drain-related stuff

Performance of our surface water drains
The Aberdeen area had been very wet for the last month or so – a real test of our surface water drainage system. The good news is that the front of the property is now well drained. Diverting the ruptured field drains, damaged when our domestic water supply was installed, into our surface drainage system has worked.

To an extent the drain has transferred the problem from the top end of our property to the bottom. When we got on site, the area around our soakaway had some standing water and soft ground. Some of this could be surface water that could not run off because of our earth-moving. It went away whilst we were on site and had not returned when we left. Ric checked the inspection chamber very recently, after a couple of days of heavy rain, it had about 30cm water in it, he was comfortable with that. Related to this, our concrete sump at the bottom of the property (that used to drain an extensive concrete ramp) has the highest level of water in it that I have seen. We will check water levels at Christmas and decide what if anything needs to be done.

Drain cover for our concrete tank
Ric had dug out space to access the concrete tank, for cleaning and pumping. He laid the concrete around the entrance earlier and took the opportunity to fix a drain cover mounting in place.

The space under the manhole is open to the tank. We never got round to getting the sludge out of the tank, we will need to hire a pump to get it out through the manhole.

Designing our garage forecourt
With the floor slab in the garage, we are planning access from the trackway. The garage is at a lower level that the trackway and we want to limit the possibility of flooding. At the same time we need a large and level enough forecourt for two car-parking spaces and the turning area we need to provide for fire engines.

Our thoughts are to install shallow kerbing along the boundary edge of the trackway to limit run-off down towards the garage. We will run paving downwards to a low point in front of the garage and install a linear drain that extends from the garage door across to the front door area – 8 metres total. We will put a sediment trap in and drain it into our surface water system. Separately, Ric completed the last segment of surface drain during this visit, a gutter downpipe running just round the corner from the garage door into a spare socket we left for that purpose. He included the extra connection for the sediment trap/linear drain.

The last run of surface drain, for the furthest gutter downpipe

The drain runs from the downpipe into the socket we left in the main drain

Ric added an extra fitting for our linear drain that willrun from teh front door to the garage.

Porosity testing
Thinking about our raised drainage mound: I have a copy of ‘the’ report on how to do the drainage mound that will dispose of the effluent from our septic tank. It describes a falling-head percolation test for the sandy material we plan to use. The outcome is the ‘Grant time’ i.e. how long it takes to drain 500ml water through 200mm sand in a 110mm drain pipe. It must be between 15 seconds & 120 seconds and must relate to the ability of the ground under the mound to distribute the effluent (called the Long Term Acceptance Rate) – a more-porous mound over less-porous ground could allow seepage over ground. We will test for the LTAR at some point.

I checked our locally supplied builders sand, sharp sand and the quarry dust we used as blinding. All are way too slow to use – 420s, 290s and 220s respectively. We need to look at sourcing a fine gravel and a coarse sand that we can mix to get the characteristics we need.

The 110mm pipe has 20mm depth of the test material. The scourer sponge on top is to stop water disturbing the top layer as it is poured in. The bucket has a hol in it so water drains out of the gravel once it has flowed through.

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:

1. 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.
2. 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
3. Tying this foundation into the Front door foundation, which is single leaf blockwork.
4. 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.

Over budget & behind schedule

Foundations and drains – way over budget and running late…

The last few months have been a bit of a roller-coaster for us. We have got masses done, but my estimating has broken down quite seriously. The plan was to get foundations done comfortably in July and complete both sets of drains in September. Here we are, with foundations spilling over into September and a half-completed surface water drainage system. We have gone around £2,500 over budget with more to come to finish the job. The full cost may easily be double the estimate by the time we finish.

My concern is mostly cost. The time delays are annoying, but we do not cost our time, and it does not matter if we take weeks or months longer to get finished. It does matter if Ric is spending his time on lower grade work like digging trenches – we need him doing the planning, complex stuff, applying his specialist knowledge and transferring skills.

Trying to tease out what went pear-shaped:

• I estimated costs for materials based on ideal trenches. Our ground was quite a bit more bouldery that I expected based on when George dug our fencing strainer posts. Mechanical digging was slower and trenches wider and deeper, so we used (much) more digger time and materials than estimated.
• I had not estimated the time needed to hand-dig foundations at all well, it took longer than estimated.
• It took longer than expected to break through our hardstanding.
• I underestimated the amount of pipe, the number of fittings and their costs.

Ric took the pragmatic view that anything involving digging into the ground was quite unpredictable, so was not fazed. Anecdotally other people have said the same.

How good are my estimates (in general?)

Out of 50 completed tasks on my plan, 4 incurred no costs, 28 came out under-budget, so 8 went over-budget. My notional ‘savings’ for under-budget tasks are around £13k, the notional ‘losses’ are around £5k, I am still nearly £8k underspent on £154k spend to date (includes purchase). Twelve tasks were within 10% of estimate, 15 are more than 25% out. None are more than 100% out, yet!

Following my miscalculations, I reworked all tasks involving groundworks, including landscaping and handling spoil.  I used experience to date to allow sufficient digger/dumper time and materials. Unsurprisingly this has increased the cost of completing the whole project, but not outside my ‘expected’ upper and lower limits.

Surface water drains

Surface water drains: We sounded out the architect on running our surface water drain above the foul drain, in the same trench. He was not happy, concerned about settlement. In practice though, our trenches ended up wider than we anticipated, so Ric compromised and ran the surface water drains in the same trenches, but higher and to one side. The runs were to be very similar. The north run was to go right up to the north-west corner, to take a gutter downpipe from the west-facing roof. It took downpipes each end of the single-storey section, then round the corner and downpipes from either end of the east-facing roof. The south run started at the south-west corner of the steading, to take a downpipe from the west-facing roof, then headed across the south end of the courtyard with laterals into the courtyard for downpipes on all the roof sections facing the courtyard, before joining the other run. In due course, the drain then is to run south to a soakaway. That is for another day, though. Anyway, Ric cracked on. He had time to get the drains laid in the existing trenches. He buried connections for the missing laterals, with end stops in. The surface water system does not have inspection chambers, so we added enough rodding eyes to be able to clear blockages in the long runs of pipe.

 Thinking ahead – extra connectors: He also buried a couple of extra connectors, one at the north west corner, another on the east side. These were in the event of us wanting to run French drains to clear our rather boggy patches.

Thinking ahead – water pipe: Even more cunningly, he laid blue water pipe from roughly where the rising main will come out of the floor slab, near the front door, and run through the west wing (under the floor slab) then into the drainage trench as far as the caravan. This will be a water supply for the bothy in due course, but we connected it temporarily to the caravan water system. He also plumbed the caravan sinks into the drains. We now have toilet, sink and shower wastes all working!

Thinking ahead – electrical cables: Ric ran two electrical cables from roughly where our distribution boxes will be, near the front door, alongside the blue water pipe into the drain trench. They run a) to where we need our pump for the raised soakaway and b) the bothy. We did not connect this to the caravan electrics, because the supply is temporarily on the west wall of the west wing. We will hang on to our butyl-covered cable that runs over ground. I forgot to ask for a cable to our polytunnel, Ric suggested running one in the sand blinding below the floor slab in our north and east wings.

Qualified ‘Yes’ from Building Standards

He topped up with gravel, took more photos and, at the last minute filled the trenches, working till 11pm or so. That was the end of his endeavours for this year. A pretty amazingly productive session.

I put the photos on my OneDrive and sent a link to Building Standards. They replied quickly saying they had selected one or two for their records. Their one quibble was around the high connection from our main bathroom to the outside drain. It goes through our foundation blockwork, then has to drop down to the inspection chamber, some 60cm lower. We put in a vertical drop, with a rodding point at the top, to access the drain back into the bathroom. They pointed out that it was more likely to block at the bottom of the vertical, where we had a simple 90 degree bend. They wanted that changed for two 45 degree bends and suggested the rodding point should be down the vertical. A job for Christmas.