Week Four – Boring it Isn’t

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.

The sheathing looks like a solid plastic pipe but is in fact riddled with slits to allow the water in the borehole to fill the pipe. The pump, when it arrives, will live at the bottom of the pipe.

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.

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.

The SW corner of the barn was taken down,

 ready for more concrete foundation to be poured.



The barrows had a well deserved in the sun after all their hard work

Talking of drilling, we did some more tiles, up on the scaffold. One thousand done, only 3 thousand to go.

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.

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

Week Three - The End of the Beginning - Maybe

The arrival of a cement mixer on site reminds me of that famous 2^nd world war photograph of troops raising the US flag on the island of Iwo Jima. Maybe this is our Iwo Jima moment. The moment when reconstruction starts. There’s still a lot of demolition to take place, but where there’s a cement mixer, there’s cement, which means bricklaying is about to kick off. The end of the beginning. Or am I getting carried away?

The name is Bond. English Bond. I think I’m turning into a bit of an anorak. I’ve started to get into brick bonding. I find myself gazing lovingly at brick walls trying to spot the pattern of the brickwork – the bonding as it’s know by the cognoscenti. Firstly, note that the long side of a brick is called a stretcher, and the short side is called the header. As everybody knows, English bond consists courses of bricks laid so that the face of the wall shows alternating rows of just headers and just stretchers. Flemish bond consists of rows in which headers and stretchers alternate within the course of bricks. The usual Flemish bond is header stretcher header stretcher. What would you call a wall which shows nothing but stretchers? Boring, yes, and it’s known as stretcher bond which is sadly just about all you see these days. Ah for the good old days. Now, looking round the barn it seems as though the original bricklayers made things up as they went along. Maybe they threw dice every morning. The bond on the barn consists of English bond for the lower part of the plinth and several different variations on Flemish bond in the upper courses. In some places it’s 2 stretchers, a header, 2 stretchers a header. Sometimes 3 or 4 stretchers and a header. And then they throw in a row of headers or a row of stretchers just for fun. Does your head in doesn’t it. I need to get out more.

As far as I can see underpinning seems to consist of excavating under the foundation

and then pouring a load of concrete into the hole.

The hole is shuttered both sides of the wall with large sheets of plywood to shape the concrete as a defined block under the wall rather than an enormous blob. At the cost of the stuff I’m all for that.

And when it’s gone off (set, to you and me) you remove the shuttering and backfill the hole with rubble and top off with soil. This is done at hit and miss intervals along the wall, and then you go back and do the gaps in the same way so you end up with a continuous foundation a metre deep.

If you think that sounds like it takes ages and costs a fortune you’d be right.
The concrete for the underpinning arrives on the back of a lorry

I was waiting to pay for the concrete, feeling guilty at just standing there watching the guys running back and forth with barrowloads of concrete

It occurred to me to join in. I asked one of the guys if I could do a couple and, surprise surprise, he promptly gave me his barrow. (To be fair, he did go and get himself another one...) So I did few barrow loads. Cheaper than going to the gym. Mind you, I walked, and, when it came to shooting the load down the slit between the shuttering and the wall, I left that to the experts.

The floor in the north projection, the utility room, had to be lowered by around a metre. 

More tiles were taken off the roof

 which the guys seemed to enjoy doing

We had state of the art gravity powered technology for getting the tiles down to the ground. It will be interesting to see the machine working in anti-gravity mode when they put the roof back on.

On his first visit the warranty inspector said that the roof tiles should be nailed down to prevent them from being lifted off by wind pressure. This meant that they would have to be drilled – all 4000 or so of them.

The builder suggested that if we had nothing better to do we could get some drill bits and start drilling. At first I thought he was joking but next day asked him if he was serious. I was disappointed to hear that he was serious. So I went down to the local diy supermarket, bought 3 masonry drills and rummaged around in the garage to find the Black and Decker the family had bought me some years previously. It had been used about twice, maybe three times in all that time. Poor thing was in for a shock.

Courtesy of our newly installed cement mixer, rebuilding the southwest plinth wall  began

On top of the concrete foundation poured earlier you add a couple of layers of engineering bricks, (hard, water resistant) a generous helping of regrades (euphemism for seconds - you don’t need perfect bricks below ground level, seconds will do fine)

Leave for a few days to marinade (go off, set) and top it off with several layers of blockwork (you will by now, of course,  instantly recognise the blockwork version of stretcher bond)

Once the plinth has fully gone off the timber frame, specifically the sole plate, a piece of oak several metres long and 7 inches by 8 inches cross section (yes I know that's mixing my measures but that's what they do ...) is lowered onto new plinth

Talking of sole plates and wall plates, had a bit of a shock when one of the pieces which, from the side, looks in good condition, turned out to be rotten in the centre. Nuther couple of hundred quid to stump up, ordering a replacement piece of green oak.

This meant, had to get the acrow jacks up under the  top wall plate taking the weight of the frame it from there. So, on the blower to track down some tall acrows.

Had a bit of rain overnight so the stream is in full spate.

And finally ... a couple of shots to illustrate this week's developments

Week Two – Be your own Quantity Surveyor

Big changes this week.  To make an omelette you start by breaking eggs - lots of eggs got broken this week. It started with the buttresses on the southwest section of plinth wall

They were removed, and and with them out of the way work could begin taking down the plinth wall the buttresses had been holding up.

Then, to take some weight off the timber frame of the barn, about half of the tiles (clay pantiles) were stripped off the roof. This was done “carefully”, as required in the planning permission, so as to preserve as many as possible for the re-build.

What seemed like acres of polythene sheeting (procured by your friendly local procurement manager/quantity surveyor) were battened into place.

With the southwest part of the timber frame safely jacked up on acrows, that section of plinth could be “carefully taken down” as also required by the planning permission. This exposed the depth of the celebrated Chalk Floor.

Many of the bricks from the demolished walls are of no further use except as hardcore, 

but some can be cleaned up and re-used elsewhere on the barn.

Having removed the section of plinth they set about digging the trench for the foundation of the new wall,

And starting to dig holes for underpinning the foundations along the south wall

We bought the concrete for the foundations (grade C30 of course ...) from a Company that does the mixing on site. That way you only pay for what you need – about 4.6 cubic metres in the first instance. It’s a great system, the only down side being that the stuff has to be barrowed from the wagon to the trench.

At about 27 barrows per cubic metre, you can work out how many trips back and forth the guys had to make. And once the last barrowload has been dumped in the trench you whip out your credit card and pay the delivery guy. Feels odd, paying for cubic metres of concrete like it’s part of your weekly shop.

The roof, the floor and the walls will need insulating. So we're in the market for Celotex - shed loads of it. Or should that be lorry loads of it. Articulated lorry loads of it. It's amazing the variation in price that's out there. Spent many a happy hour surfing and ringing around to find a good deal. Nearly said the best deal. And therein lies part of the problem - how do you know when you've found the best? When do you stop looking?

And how much do you need? – which is where we put our quantity surveyor hat on. We looked at the design for the roof construction - 2 layers of 100mm Celotex, one on top of the rafters plus one inside, between the rafters. Focussing just on roof for now (walls and floor will need further shed loads, but they can wait for now) we measure the area of the roof from scale drawings and a bit of nifty trigonometry, double it, and Bob’s yer father’s brother. What keeps me awake at night is that we may have get a decimal point in the wrong place. We could end up ordering either 10 times as much as we need, or possibly just a tenth. Not sure which would be worse.

During the week our Builder asked us to get some basic stuff - cement, sand, bricks, blocks, and some tile batten - 2 by 1 lengths of wood. Now (humour me here) there are seventeen rows of tiles, and the main roof is 22 metres long. Double it for 2 sides of the roof. You also need battens which run up the roof. And then there’s projections, each of which has a roof approximately 4m by 4m. Our builder suggested 5 bundles at 200m per bundle for starters. That seemed OK to me till I realized I was ordering a thousand metres of wood. That’s a kilometre. Never had to order anything like that before. And that’s just the start. Gulp.

The guys set about digging out the soil which over the years had heaped up against the N wall. This will help reduce the load on the N plinth wall and diminish the risk of damp - the ground floor at that end of the building is partly underground due to the slight slope of the site. At least the digger is singing for its supper. More of a banquet actually.

And finally, a couple shots of the barn showing what has changed since last week