Holdfast Training Services Trial Blog

“Believe me, my young friend, there is nothing – absolutely nothing – half so much worth doing as simply messing about in boats.”
― Kenneth Grahame, The Wind in the Willows

My other day out of the office was prompted by a letter from the Environment Agency to FirstPort property services stating that the concrete defences along the river Thames were damaged and needed repairing.

FirstPort did not know it was their responsibility to look after the defences. It turns out they got the management contract for the development from Berkley homes who built it. This particular detail was in the documentation but no one at FirstPort noticed it. So it was a shock to them when they received the letter in the first place.

The quayside in question is on the site of Brunswick PowerStation (think Battersea cut in half lengthways). The quayside was built in 1948 and therefore designed to the DSIR code. I was chatting to John about this yesterday and the code is so old it even pre-dates him! The code didn’t really take environmental factors into consideration and so the concrete cover to the steel is as low as 35mm. EC2 would say it must be a minimum of 65mm. Additionally these large public projects in the post-war years were a good way of employing soldiers returning home after the war to a weak economy and high unemployment. So soldiers would be given jobs on construction sites, this one included. Their workmanship was a bit dodgy as was the compaction methods of the time meaning the concrete is not as dense as you would expect from modern methods.

Then…

…Now

The combination of little cover, poor compaction and an aggressive environment has resulted in some fairly substantial corrosion to the steel. Chlorides in the environment penetrate the concrete and the steel corrodes. The corroded steel has a high volume than the original steel and therefore cracks the concrete. Which lets in more water and the corrosion starts again. It’s a vicious cycle.

So we hired a boat and a concrete cover meter and went and had a look.

It is repairable. The problem is that it’s going to be an ongoing maintenance burden which will ultimately be paid for by the residents through their maintenance fees. The bill for this will be over £100k, which split over all the properties in the development is not a huge amount of money, but if they have to do significant repairs each year – which they might – the residents are going to get pretty tired of it pretty quickly.

I’ve got to go to a residents meeting there in a couple of weeks to explain this to them all. Not looking forward to that!