Let’s play conservation spot the difference at the Folly….

Wont be long now

Wont be long now

Nearly finished repairing the folly, now for a little makeup on the new clunch stone. So what is clunch?

This little bit is from ‘Wiki’

“The stone is a chalk from the Lower Chalk of the Cretaceous age, the period of geological time approximately 145 – 66 million years ago. It is greyish-white to light beige in colour, often with a greenish tinge. The latter is due to the presence of glauconite, the potassium and iron aluminium silicate mineral that is also found in Kentish Ragstone. The stone has a gritty texture due to the frequent presence of shell fossils. This stone has been quarried at Totternhoe Quarry in Dunstable, Bedfordshire by H.G. Clarke & Son since 1920.

It is a particularly soft when quarried and subject to chemical and wind erosion as exposed material, i.e. when unrendered in paint, stucco or cement. It can be cut by a saw when in its softer state; when it has been quarried out of the ground it still contains a large amount of water. When the stone dries out it becomes harder, and is not as easy to cut.

Orwell clunch pit

Orwell clunch pit

Clunch is generically a soft limestone. It can be rich in iron-bearing clays or be very fine and white — in effect just chalk. It is used in various parts of East Anglia, where more durable stone is uncommon, and can be seen frequently in and around Thetford — mostly now for property boundary walls where not a long-lasting material, but it is also used for some building walls, especially in traditional agricultural buildings.

In Ely Cathedral it can be seen in some interior locations. The nearby village of Burwell has its civil parish magazine named after the building material. It is found in the village of Seale in Surrey and in Farnham.”

wimpole_dsm_hs copyv

Guess where the clunch pit is behind Cobbs wood farm?

Originally the clunch used around the estate would have come from local clunch pits, nearly every village in SW Cambridgeshire has a clunch pit. The main one for Wimpole seems to be behind Cobbs wood farm in the woods but there is a bigger one in the local village called Orwell. Mostly the pits produced chalk  and chalky marl mostly used for making floors and tracks although a type of cob brick was made with it too. The clunch (Burwell/Totternhoe stone) only appears in lens within the chalky strata so a pit only every produced a small amount of this stone.

Woods stripped away and there you have it!

Woods stripped away and there you have it!

Wimpole Estate NT

Clunch weathers in many different ways however what we are seeing at the Folly is the semi hard face of the stone eroding in patches which leaves a soft fragile core face of stone exposed.  These areas are more susceptible to weathering and the decay accelerates as the water gets into the stones and it crumbles fast. In addition once the outer face is lost it reveals the original light cream stone colour which looks blotchy when viewed against the rest of the surrounding stone, the original has built up a patina over the last 240 years. We had a building which looked like a Friesian Cow, patches everywhere.

Area of clunch face loss Area of clunch face loss

The conservators have been using their artistic touch to colour these areas to match the surrounding weathered and aged stone – the appearance is to capture the years of lichen and algae growth.

A repaired section (around the centre stone) A repaired section…

View original post 218 more words

About Sadeik

You may ask why "Sadeik" well it means friend in arabic. Worked in Jordan a lot doing tree surgery you see. I have worked in forestry since I left school with a two years in Telecom. Went back to forestry and tree surgery as it may not have paid as much but was far more interesting and dangerous. Spent a lot of years mountaineering, caving and canoeing too. At 29 I went to Bangor University to study Forestry and soil science then did an MSc in Water engineering all very interesting. By a quirk of fate in 1995 ended up helping sort out the woodland and park at Wimpole, funny thing was then I only intended to stay six months or so, but 18 years later I'm still here learning all the time. That's the best bit, if I wasn't able to learn something new every year I would not have stayed and as you get older you realise that the grass is not so green in the next field after all. In fact my patch is getting greener while much of the rest is getting browner.
This entry was posted in Uncategorized. Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s