Reclaiming clay bricks is an obvious solution to help decarbonise new buildings. So why is this not business as usual?

Here are the challenges…but also the solutions!

It is estimated that around 2.5 billion bricks are demolished in the UK each year (around five million tonnes), which is roughly the same amount made or imported for new build. Out of this waste, only about 5% are reused as bricks - the rest are downcycled, usually crushed for road base.

Given the embodied carbon of making new bricks (which is not as high as you may think – more on that to come in a future post), why are so few bricks reused as actual bricks? Like most things in life, the answer is not simple:

Firstly, you need to get the old mortar off. Until very recently, the only way to do this was by hand with a bolster and mallet. This is very difficult - and believe me I’ve tried! My soft hands - more used to a keyboard and mouse - were no match for these hard materials, and a tough afternoon’s work yielded about 20 usable bricks from a pile of over a hundred. Crumbly historic lime mortars make things easier, but modern cement (and even modern lime) mortars make this a major challenge.

This is why reclaimed bricks cost more, often over twice that of newly made ones. Despite this, the demand for certain historic bricks, such as London Yellow Stocks, is high. So high in fact, there are reports of unscrupulous traders reversing into church walls and stealing the bricks – behaviour that will surely see you banished to Hell at the end of your life! The effort involved in obtaining and preparing reclaimed bricks means they are a niche market for upmarket reclaimers: ￡2 a brick is a drop in the ocean for a wealthy Londoners building a kitchen extension, but it doesn’t work for the wider construction industry.

Then there’s quality assurance: New bricks are mandatorily made and tested to a European harmonised standard and CE marked accordingly, ensuring they are durable against frost, sufficiently strong, and meet other key performance requirements. This is hard to demonstrate with a reclaimed brick – probably not an issue for that kitchen extension, but presents too much risk for a big developer.???

Another factor is that bricks are not just bricks. Up until the early 20th century, brick buildings were solid, load bearing structures. Firing of bricks was highly varied back then, so within any one production batch, the quality and appearance of the bricks varied broadly. Thus, they were sorted into ‘facings’ (the ones you see) and ‘commons’ (the ones you don’t). These were carefully laid so that the durable and attractive outer ‘facings’ were exposed, and the inner ‘commons’ were used elsewhere. If you dismantle a typical 19th century house, around two-thirds of the bricks will be commons, and won’t be much use for resale.

These days common bricks simply aren’t used - their market was replaced long ago with concrete blocks, or timber or metal studs - all of which are much cheaper and faster to build. The only value for reclaimed bricks is for facework.

Another obstacle is that many newer bricks from the 1960s to the 1990s have great technical properties, but are frankly, ugly! Those textured brown and cream wirecuts look as dated as clothing from the same era.

All of this explains the currently tiny 5% market for reclaims...

BUT THERE IS HOPE!...

Over in Denmark, a company called Gamle Mursten has found a way of automating the reclamation process, by vibrating the mortar from bricks, which have been carefully dismantled on site, then moved to a purpose built factory. They cannot reclaim every brick type, but there are many which they can, and business appears to be booming. Not only that, but they test their bricks in-house to a new EAD (European Assessment Document), meaning they can be sold with a CE mark, ensuring their technical performance to contractors, building owners, insurers, lenders and Building Control. Although they are currently the only firm in Europe to do this, it paves the way for others.

Meanwhile over in Quebec, a masonry contractor who began reclaiming bricks by hand as a sideline during the sub-zero Canadian winters, developed the ‘Brique Recyc’ machine, which has to be seen to be believed! At just 500 kgs, it can be installed on a scaffold, so that bricks can be simultaneously dismantled and cleaned, immediately ready for reuse. It cleans up to 500 bricks per hour, and features laser guides which determine where the brick stops and the mortar starts, before abrasive wheels grind the mortar from the surface. Brique Recyc work by leasing their machines to contractors, and they now have a distribution base in Calais, France, ready to enter the European market.??

Link to the Brique Recyc machine in action: ??https://youtu.be/bILOCs-BZ3s

But what about those poor old ugly 1970s bricks that have decent technical properties but nobody will love? Well, I have an answer for those too. Mineral silicate paints, such as those made by German company Keim, are a great way of permanently staining bricks to a more homogenous or completely new colour. These paints are colour-fast, non film-forming, vapour permeable and durable, so have none of the technical or maintenance issues associated with most masonry paints.

Alternatively, historic techniques often seen around the Baltic coast, such as smearing a slurry of lime mortar across brickwork to provide a thin, semi opaque render can be stunningly beautiful. The technique is called Steinsichtige Schl?mme in German, and isn’t used nearly enough in my view, but do take a look at Chipperfield Architect’s Gallery Building Am Kupfergraben in Berlin below (now called Haus Bastien) and see if you agree. ?

So despite the challenges, the future for reclamation of brick is bright! Please do get in touch if you would like advice on brick reclamation, materials reclaim generally, or absolutely anything else to do with bricks, terracotta and earthen materials!

#circulareconomy #decarbonisation #brick #wearearup