Great excitement this week as the boring began. First to arrive on the back of a low-loader of the was the rig for the water borehole. It’ll provide water for consumption as well as water at 12C year round for the ground source heat pump. The idea is that the water is cooled by the heat pump to 2C and returned to the ground via a soakaway. The heat thus extracted is used to warm the barn. Simple huh?
Interesting slogan for a drilling company.
A pile of blue sheathing was delivered -
to line the hole once it’s drilled.
Also delivered were bags of glass pellets used to pack the hole around the sheathing. It's cheap, clean and inert.
The blue sheathing is inserted into the hole using the same head as drives the drill.
The compressor arrived later – it's used to blow out the loose material generated by the drill. Makes a right mess because it's blowing out ground up chalk
Drilling went really well. Top seven metres are aggregate - a hard packed mix of stone, gravel and sand, then it's chalk all the way to Australia. Actually they stopped at 52 metres and were in the water table from about 5 metres down. That means the borehole effectively contains a column of water about 150mm (6 inches) in diameter and 47 metres deep. A lot of water. They were almost finished in a couple of days. In fact, they were slotting in the last section of blue pipe when the drilling head slipped and broke the plastic pipe. No problem. Just pull it back out and stick in another bit - they had a few spare sections. Wrong. The damaged section down the hole was stuck and couldn't be pulled out. The glass packing material was doing its job. Which meant they couldn't join the last section of sheathing to the pipe already down the hole. In the end they decided to abandon that hole and drill another one, 5 metres away. Amazing. A borehole 52 metres deep , 2 days of work, 2 days hire of huge machines on site, all scrapped because of a bit of broken plastic. I guess the risk is they could spend longer trying to rescue the first hole than it would take to drill another one.
Drilling went really well. Top seven metres are aggregate - a hard packed mix of stone, gravel and sand, then it's chalk all the way to Australia. Actually they stopped at 52 metres and were in the water table from about 5 metres down. That means the borehole effectively contains a column of water about 150mm (6 inches) in diameter and 47 metres deep. A lot of water. They were almost finished in a couple of days. In fact, they were slotting in the last section of blue pipe when the drilling head slipped and broke the plastic pipe. No problem. Just pull it back out and stick in another bit - they had a few spare sections. Wrong. The damaged section down the hole was stuck and couldn't be pulled out. The glass packing material was doing its job. Which meant they couldn't join the last section of sheathing to the pipe already down the hole. In the end they decided to abandon that hole and drill another one, 5 metres away. Amazing. A borehole 52 metres deep , 2 days of work, 2 days hire of huge machines on site, all scrapped because of a bit of broken plastic. I guess the risk is they could spend longer trying to rescue the first hole than it would take to drill another one.
Then to cap it all, one of the guys working on the rig hurt his hand, mercifully not seriously. Work came to halt for the day as he was driven off to A&E by his colleague. In fact they decided to pack up and go home (Tyneside) for the weekend.
We were left with a rather forlorn looking rig, and some broken pipe
Some more underpinning was done this week, inching our way round the building. The departure of the drillers left the way clear for a delivery of concrete which had had to be postponed because of the drilling operation.
ready for more concrete foundation to be poured.
The barrows had a well deserved in the sun after all their hard work
We've been really blessed with the weather – since the start at the end of January we've had no real disruption due to rain. It's been cold at times (2C on Monday) and there has been some drizzle. Friday was amazing - blue skies and 14C. Just perfect for trundling barrows full of cement around. Makes you feel good to be alive.
One of the things about doing the project management yourself is that you get involved in technical decisions, as well as the purchasing side. For example, we discovered that the plans for the floor levels don't work. In the kitchen, because of the Chalk Floor (yes that one again) there's not enough clearance between the finished floor level and the proposed bottom of the window for a worktop, and the solution could be expensive. (Mullions here, mullions there, pretty soon you're talking big money.) So we're having to find a workaround with our builder.
One of the things about doing the project management yourself is that you get involved in technical decisions, as well as the purchasing side. For example, we discovered that the plans for the floor levels don't work. In the kitchen, because of the Chalk Floor (yes that one again) there's not enough clearance between the finished floor level and the proposed bottom of the window for a worktop, and the solution could be expensive. (Mullions here, mullions there, pretty soon you're talking big money.) So we're having to find a workaround with our builder.
We also discovered this week that the proposed design for the wall insulation doesn’t give the required U-value – it relies solely on insulation between the studs (the vertical bits of wood in the frame) and doesn’t take account of the studs as cold bridges. So we've had to come up with a modified design and re-do the calculations to confirm we're getting the desired U-values. Still, it's only insulation, so no sense getting hot under the collar about it.
And finally, a couple of pictures showing where we're at by the end of the week
And finally, a couple of pictures showing where we're at by the end of the week
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