Saturday, 17 March 2012

Wear and tear...

Walking down to the town in Chinon the other day we spotted a fine piece of erosion on the stonework of one particular house..

The house is in an exposed spot, overlooking the town, but we wondered why this particular section of stone should suffer so badly whilst the rest is relatively clear.

The stone in question is tuffeau, a marine sedimentary rock found throughout the Loire Valley. It has a very low density compared with other rocks; it is half as dense as granite and an amazingly high porosity - up to 50% compared to 1% for granite.

So possibly the section of stone beneath the window was more prone to seepage which in turn caused the damage we see on the above photo.

Despite all this, however, many old buildings built from tuffeau are still standing. The Chateau at Ussé is a wonderful example and at the other end of the scale are the many longères still to be seen in the region.

It defines the regions buildings and lends a subtle mellowness to our towns and country dwellings alike.

All those engaged in renovation work based on removing concrete rendering and revealing the original stonework are to be applauded!


Diane said...

Interesting post, I learnt something new about stone today. Diane

Colin and Elizabeth said...

So did I, Diane, whilst researching for the post!!

Tim said...

Looking at the way the erosion is in lines, I would hazard a guess that the solid lines are harder tuffeau than the 'holes'... wind could easily have caused this erosion over time... the particular lump is a good example of the way the little fossils that make up the limestone changed over time... a bit like tree rings... but longer time period.
And keep an eye out for scraffiti... the stone lends itself to it.
Anything from records of how many Germans passed a spot during the war [near Chaumussay]... to a drawing of a church [on one of our doorposts] to records of how many bales, sacks, etc. have been loaded into the grenier.
And the beautiful tower at the Chateau at le G.P. if they ever let people up it again has some wonderful "we was here" scriblings from the C18th onwards...