Should be the consistency of thick brownie batter

So here's my recipe:

• 1 part cement,
• 2 parts sand, 
• 3 parts gravel.
• A little water

You will also need:

• A wheelbarrow to mix in
• A strong form to pour into
• A pointy stick for rodding

Mummy may not want you to do this in the kitchen.

A plasterer was there doing the wall when I was pouring the first section of concrete. It's always a mixed blessing having someone standing over your shoulder giving you advice.

I'd already got the frame so that I thought it would hold the concrete. There's a good You tube video demonstrating the result of not properly keeping the two sides together.

The plasterer wandered over and told me that it was no good, and I'd have to push soil down the outside edges. I was just about to do that.

Later he came over when I was just about to start mixing. "You mix the cement and sand first, then add the gravel later," he told me. I was going to do that, but I thanked him politely.

"You weren't going to do that, were you?" He said next. I wasn't sure what to say. It's a fine line to tread between idiot and expert.

He also told me the stones in the gravel were too big, which other people have also said, but I've mostly been ignoring their advice. I've been using what gravel has been lying around, and not overly worrying about finely grading it. Certainly when I have used smaller gravel it's been easier to mix and pour, but I hope that it won't make much difference structurally.

Over the past couple of years I've been steadily producing gravel while getting a little half-decent top-soil for the garden as a by-product. It's not so much that the soil in the garden has a lot of stones in it, more a case that the stones in the garden have a little bit of soil mixed in with them. So it's been nice to find a use for them, and I've been loathe to pay money at the DIY store or pay trucks to bring a load to the house.

I've also been following various bits of advice, for example from Oli who suggested that washing the gravel was important.
This site has some useful ones, including this:

"Your cement should be the consistency of thick brownie batter. You want to have to scoop it into your mold, not pour it."

There's another good one about putting your concrete mould on top of a washing machine after you pour the concrete. Great idea as this will get the bubbles out, and the bubbles are air, and air will make the concrete crack. The reason it will make the concrete crack is that as the concrete heats up, everything in it will heat up, and that includes any air. As concrete heats up, it will expand at about 12 parts per million per degree. This is not a lot, although it adds up to one centimetre over a 25 metre length and a temperature rise of 40 degrees, which you'd get over the year. Air expands a great deal more as it gets hot, and any bubbles are going to be little pressure bombs adding forces in all directions, some of which are going to crack. I expect to see a few cracks forming in my earlier attempts at concrete, but the later ones should be OK.

Putting the poured concrete onto a washing machine is a great way of shaking all those bubbles out, unfortunately impossible for my 1.6 metres lengths, which I hope are bonding with the rubble below them.

Plus One - Plucky and Simple

I've just discovered a great shop. Plus One is its name and plucky and simple its byline. Plucky, I'm not sure whether applies to a shop. Simple it is not.

The immediate excuse for going there was to get some elastite, which we need for the concrete job. At least we thought we may need it. Actually the lengths of each stretch of concrete are short, and we can put gaps at the end of each one, so the 10 millionths per degree expansion coefficient of concrete, which we would perhaps have needed to take into account over the whole 18 metres of the job, is not going to be a big deal.

The job itself is completing a low wall along our western perimeter. We are putting a fence up there, with aluminium posts sitting in concrete feet spaced at 1.8 metres. We also want to put something in there to keep the perimeter continuous and to avoid mud flowing from the neighbour's land, which is a couple of centimetres higher.

At first I assumed we could easily just get a few breeze blocks or some more fancy blocks and put them along in a row, but this turned out to be difficult. We couldn't find any the right size with the right finish on top. To get them in properly we would have needed to put in something below and fill in the holes on top with mortar. We thought we may be able to get something that looked nice, but since the feet are concrete, the thing that will look nicest next to them is more concrete.

So we thought about curbstones. The problem here is that the curbstones come in 600 mm and 900 mm lengths, but the gap we're trying to fill is 1.6 metres. So we'd need to cut the curbstones into 200 and 400 mm peices and fix them all together. And that's possible, but everyone with the ability to cut curbstones is too busy at the moment. Consumption tax is going up on 1st April, and everyone is frantically getting the work done that was ordered before the tax hike. We could wait, but we need to get this done within the year since we're going to plant a hedge next to it, and we've applied for a grant for that from the city, but it needs to be done by the end of March.

So the best option seems to be pouring concrete. It's certainly not going to be the most expensive option, unless it is a complete disaster and needs redoing, but it may take a bit of time.

I'd more or less decided over the weekend that this was the way to go, but on Monday morning the gardener who is in charge of the fence and hedge project turned up with the curbstone catalogue and set off trying to find cutters for them. It wasn't until Monday evening that he realised it was going to be more difficult. So we set off to Watahan Monday evening to get some concrete and bits of wood to form it.

Watahan is not a bad shop. The people who work there are usually a bit older and know what they're talking about. We were asking the guy in the wood section about building a former, and another customer overheard us and came over to give some advice. About half an hour later, we left the shop, a lot wiser, but not having bought anything. We did hear about Plus One for the second time.

And Plus One was A DIY oasis. I could tell at once that it was going to have good stuff from the people in the carpark. A lot of small trucks with men in work clothes, towels wrapped around their heads and tape measures in their pockets. Inside there were aisles and aisles of tools and parts, bits and bobs, materials hard and soft, long and short and with many shapes, textures and functions.

I looked to see if they had any elbow grease, having heard that was an essential ingredient for mixing concrete, but their stocks didn't quite go that far. I didn't check whether they had any left-handed screwdrivers.