All About Clunch
Well, we all think we know about clunch, although for most of us, the sum total
of our knowledge is perhaps that it is that problematical stuff, of which there
seems to be a great deal hereabouts, to be associated with builders and
decorators shaking their heads in a sorrowful way, and we do know what that
means! But in this New Year edition, John Norris is going to tell us all about
it, and how it relates to that odd feature of village landscape, the mysterious
Deal Hole.
THIS VILLAGE has a large number of uses for this abundant material. which lies under the higher ground to the east of the high street. The name clunch may be derived from the name of the chalk, which is the common name for the material. As so often happens with natural deposits, there is quite a large variation in the types of clunch found. Some is so near the surface that it has been degraded by cold weather, and is quite soft, whilst the clunch excavated from the lower layers is quite hard and durable, having been squeezed by the weight of the deposit above
Several houses in this village still have walls of clunch, and they perform their task well, but many that used the poorer material from nearer the surface, and consequently cheaper ,have succumbed to the hard weather and broken down. After the hard frosts of 1963-4 many clunch field walls disintegrated, and had to be replaced. The fence from the school porch down to the stile replaced a clunch wall. Part of the churchyard wall fell down but has not been replaced - -yet, and the top part of the boundary to Town Close had to go also.
Another use for this material was to make roads, especially in the fen where the soft peat was unsuitable for wheeled traffic. I guess that Whiteway drove extended right up to the village before the railway came, and was reinforced by this white clunch. Most of the local clunch came from the pits now in Reach Parish, but which were in Swaffham Prior until 1956, when Reach village boundary was altered. An attempt was made to extract some of the deeper clunch by tunnelling into the side of the valley, known as the Deal Hole. Most of the area has been so altered by the new bypass, that it is difficult to imagine how it used to be.
I remember it well, as in my first year farming here, there was no modern bypass, just the causeway built by the French prisoners of war in the late seventeen hundreds, and this valley was in its pristine condition..That summer there was a terrific storm which flooded the deal hole twenty feet or so deep spoiling many of my much needed hay bales. The culvert under the road was blocked. But water was seeping away under some lavender bushes which had been planted on the steep bank to mark the palace where the tunnel had been filled in. So the getting of a good deal by finding the lower chalk gave rise to the name Deal Hole - perhaps!
There are no buildings made from clunch in this village for the past hundred years, but a few older examples still remain, having been looked after with care and attention. The distinguishing feature of the better and harder clunch is the regular shapes of the pieces. It was possible to saw blocks of this type of clunch so that a regular tidy flat wall could be built, with the minimum of lime mortar. Several of the larger houses still have wall of this character, and show no signs of deterioration. The latest use of these cut blocks is at Anglesey Abbey, where the construction of the picture galleries in 1955 is of this material, to match that of the older building.
Buildings of the softer chalk are in the form of random lumps bound together with generous helpings of lime mortar. These walls are usually quite thick as the middle of the wall was filled with rubble. The church towers were built with a mixture of clunch and flints, which had to be renovated over forty years ago to remove the weathered clunch. The harder chalk was also known as Tottenhoe Stone, from the village in Bedfordshire where it was originally found.
I have mentioned the use of lime mortar in the construction of houses before the invention of cement. This was made locally by first heating the clunch to a very high temperature, so that it decomposed into quick lime and carbon dioxide (CaCo3 ---CaO + CO2). This quick lime was then slaked with water (carefully) to form hydrated lime Ca(OH)2. This lime is then mixed with four parts of sand, and becomes lime mortar. In time the Ca(OH)2 reacts with the carbon dioxide in the air and returns to chalk again. One great advantage of using this type of mortar is that it is easily removed. Recently the Chapel has had several alterations to the old windows, and this has been done so carefully that you cannot tell that they are not part of the original scheme of things; Lime mortar was used in the original construction, and in the alterations.
The last use I can think of for this local material is to use the hydrated lime for decoration and protection of clunch. I used to live in a house with some clunch walls and after the hard winters of the sixties, had to repair the frost damage, and this led to re-decorating. Hardiments, the local builders found the quick lime, and this was slaked in an old bath, generating much.heat This was the time to add lumps of tallow so that the heat melted it, and the result was a water-proof, but porous paint. We did this for many years until it was not possible to get the quicklime. As it happens, the winters have become much milder; in fact we have not had four consecutive days and nights of below freezing temperatures for over forty years. Remember skating?