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.

Easter Visit

We arrived on site a week after Ric had been obliged to head south for a fortnight. We agreed a shortlist of priorities for the following weeks: Start capping what is left of the walls with mortar and blockwork, to protect them from another winter of rain and ice; pull down the north-east gable-end wall (the one with half the foundations missing); finish the surface water drain including filling the soakaway with rubble; clean out the concrete tank; screen spoil, distribute it and level up the courtyard; prepare for the floor slab. Too much to do in the time we have, but we will see how we get on.

Caravan: We planned to stay in the caravan most of the time, with twice-a-week visits to Bucksburn. We brought a 3KW electric heater up with us, swapped our empty gas bottle and got hold of a third one. The first night we were freezing, we went to a supermarket the next day and bought second duvets as well as missing utensils. Once we mastered the art of putting the heating on at the right time, we were very comfortable and quickly benefited from the extra time not spent driving to and from Aberdeen. The water heater was wonderful, good hot showers, reasonable flow rates.

Mobile Coverage: I have changed my mobile service provider from EE to Tesco Mobile. I can usually get two bars of 4G in the caravan and because I can use all my data for tethering, I have better connectivity than in Bucksburn.

Jill is on Vodafone, which also has decent reception. This got tested out for real whilst we were there. Jill’s sister, Vicki, and family were on holiday in Iceland. One of them ended up in hospital and needed a scanned image of their EHIC card. We persuaded Jill’s mum, Lesley, to find the card then to get one of her friends to take the photograph and email it to us. Jill forwarded it using MMS to our niece, Lucy, at the hospital in Reykjavic. Job done. We can use our caravan in north-east Aberdeenshire as a global communications hub!

Misty: Our blue merle collie cross was suspicious for a day or so, but got to appreciate being able to get out of the cold and wet. She spent all day being excited by anything and everything going on. As last year, it took its toll – she got so exhausted she was reduced to lying in her basket to eat her food. We supplemented her diet with extra dog meat.

Caravan: We sorted the longstanding niggle about the caravan sloping to one side. We bought a 4-tonne bottle jack and I cut some plywood shims. I crawled underneath the caravan to where we had put the frame on concrete blocks last year, I jacked up the low side and pushed the shims in. It pushed the side up about 3cm and that was enough to sort out the tilt. I also greased the jacking points, which were getting quite rusty and difficult to turn.

Garden: It is a great time to be in the area, with spring springing. Jill had planted daffodils and snowdrops last year in what we had hoped was a safe area, they were in bloom.

Hedging: She gave all our hedging a good spring clean. She removed the tree tubes, cleared debris and weeds away and pruned them. A remarkably small number had died. Most were bursting into life and had not yet been cut back to tree-tube height by rabbits/hares. The latter may have plenty of other food at the moment, hopefully the hedging will get big enough to simply out-grow pests. We used a tray of hedging plants that Jill’s mum had been bringing on, to replace those that had not survived.

Orchard: We extended our future orchard in the south east corner. Jill had found another end-of-season bargain online and ordered four new bare-rooted fruit trees – apple ‘Falstaff’, apple ‘James Grieve’, apple ‘Ashmeads Kernel’ and plum ‘Victoria’. Driving up, we had stopped at Morrisons in Berwick-upon-Tweed and bought one each of cherry ‘Morello’ and cherry ‘Stella’. They are now safely planted.

Broken Glass: We did another sweep of the grounds removing broken glass that had surfaced since the last clean-up – we are still filling a bucket or two over the course of a year.

Japanese Knotweed: Had not broken the surface yet!

Rhubarb: We cropped it for the first time and stewed it!

We added a second lot of fruit trees to our orchard.

Raised drainage mound: We took time out from our more physical tasks to pin down where we would build the raised drainage mound that will take effluent from our septic tank and allow it to soak away through our otherwise not-very-permeable and high-water-table grounds. There was not a lot of choice, we found a 10m x 7m area where the concrete ramp had been, a safe distance from our boundaries and soakaway, avoiding our area of new fruit trees and the established ash/sycamore trees. Ric worked out that we could minimise the visual impact by flattening the area uphill of where the mound will be, by dumping screened spoil and levelling it. The mound will either line up with the levelled area, or will stick up a bit, but not much. What we are not sure about is whether it needs to be separated from the levelled area by a trench, or could just be an extension of it. I will check with the architect at some point.