This post is inspired by the idea that when a building is demolished, quite a lot of it can, and possibly should be reclaimed and reused in new build construction. In particular, the more modular, energy dense and commonly used an element is, the stronger the argument for its reuse becomes. In the UK, top of the list is brick. If you live somewhere else, especially a seismic area, this post probably doesn’t apply but I hope remains interesting.
The title comes from:
necromancy – the art of animating and brining back the dead
Brico – from brick and bricolage, meaning to build up from many found elements.
Shown in the picture are 1950 Cardiff area standards with the familiar, horrible, black ash mortar. I say Cardiff area standards, as apparently every local coal mine had an attached brickyard using clays and coal coming out of the mine, so there’s dozens of different maker stamps around me.
A recent paper looked at the idea of reclaiming brick. They found that 2.5 Billion bricks a year are freed from demolished buildings in the UK alone, which pretty much matches the number of new bricks made a year. Five percent of these are reclaimed. I don’t want that to sound dismissive, it represents a 125 million bricks hand cleaned and reclaimed. Economically, a good number of those are specific heritage type bricks that are needed for modifications in protected heritage areas. I have heard that London Yellows can sell at £5 per brick, compared to 50p for a new standard piece.
If we want to compete with new cheap brick, the cost of cleaning has to be minimised. The paper looked at sawing off the mortar and shearing it off with a punch. The results indicate the reclaiming activities consume as little as 0.65% of the total embodied energy of brick manufacturing (Ecoinvent, 2017), thus showing high potential for improving energy and environment. They didn’t look at the cost and energy for other cleaning aspects, like paint removal or dust collection, but these aspects are well understood. Further papers by that team are coming, looking at just how perfectly you need to remove the mortar to reuse the brick.
There are caveats. This Dutch project (video link and still below) shows the final QA stage of their brick cleaning, with people tapping them with hammers to prove intactness and setting aside if bad. The siliceous dust from the mortar (and all the other lovely things in mortar) means they need breathing suits. The process, as far as possible should be automated. It needs to be cheap, to scale (2.5 billion bricks remember) and create jobs that are not terrible.
What are the other criteria? I looked into it a little more. PAPERWORK ALERT.
In Cardiff, there is a single recycling site that accepts construction waste, so the natural place to put it is there. This means you capture little batches of fifty bricks from a demolished garden wall or garage, as well as major sites that are redeveloping a former Victorian warehouse. It means you can collect up these dribs and drabs, sort them by size and colour, and offer full amounts for building projects, which is nice. The site currently crushes them all for loose aggregate, which is also nice, as there will be a good third (at a guess) of the incoming brick is going too damaged to reuse and aggregate is a good recycling option.
Once the brick leaves the site, it is classed as waste, and under the Welsh regulations that gets complicated. CIWM recently released a report decrying the situation. (host site, and the direct pdf link) It’s a bit of a mess, and the below is my best understanding, from a Welsh startpoint and is NOT LEGAL ADVICE. Yeah. I need to say that, that’s how messy this is.
Brick reclamation is not covered by an existing Quality Protocol (Aggregate is).
The other sane, low paperwork option, a Low Risk Waste Position, is unknown as Natural Resources Wales doesn’t publish them on the website! England, the neighbouring country, does, but there is not one that covers bricks, although there is one for cob clay and another for plasterboard.
Finally, there’s the shared Wales-DEFRA guidance on things in construction that are exempt from waste regulation and can be reused. (there is one for tyre bales in construction) This route is less specific than the above cases, and would be overruled by them if they existed. Instead we have four different relevant waste classes (below), a shared limit of 5000 tonnes per project and a rule that states “you may not treat waste to make it suitable to use”. Yeah.
There are a few exceptions but the only one of that applies here is T7, which, with local council planning permission, allows you to crush bricks to make aggregate. Not much use for reclamation.
Can we just declare the bricks are not waste? Examples on this page are confusing. Section 3.1 states that soil from a construction site intended to be used on another site is ‘likely’ to be waste. Section 6.1 states that, “roof tiles carefully removed from one building, stored to retain their integrity and then certain to be fitted onto another building’s roof” are not waste. Why are the tiles not-waste but the soil is likely to be? Clear as mud. There’s another option, of declaring the bricks a by-product, but that requires “it can be used directly, with no further processing before it’s used”, which hand on heart, I think mortar removal probably breaks.
A final option, and its very silly, but it may be legally easier to robotically demolish the buildings, separating and cleaning the bricks on site (so as they leave, they are by-products). So instead of taking advantage of scale and existing supply networks, you need a portable unit that can be taken onto sites. You miss out on all the small sites feeding in the dribs and drabs of local brick though. and remember, this is THE SAME ACTIVITY as before, simply without a transport stage
This fits with an older idea of mine to strap a concrete saw to a robot arm and leave it to deconstruct and stack the bricks. A more sensible option might be a small crawler that can run along the top of a wall, cut a brick out, grasp it and lower it down the side of the wall to be picked up. It might well work, but it seems an overkill solution that only makes sense in the current broken regulatory system.
| 101208 | Waste ceramics, bricks, tiles and construction products (after thermal processing) |
| 170102 | Bricks |
| 170103 | Tiles and ceramics |
| 170107 | Mixtures of concrete, bricks, tiles and ceramics not containing hazardous substances |
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