Chiltern Open Air Museum has been working hard to preserve building techniques that could otherwise be lost forever, including a process using a local material called 'wychert' and iron age thatching with spelt, brambles and old mans beard.
 
The museum was set up in 1981 to save some of the historic buildings that were being demolished in and around the Chiltern Hills. It opened with five re-erected buildings on its site at Chalfont St. Giles, Buckinghamshire. Now there are thirty three exhibit buildings. Current projects include the re-erection of an earth building from Haddenham in Buckinghamshire, and putting a new roof on the replica Iron-Age roundhouse.
 
John Hyde-Trutch, the Buildings Manager at the museum explains 'The Haddenham building is constructed from wychert, a material exclusive to the Haddenham area. Wychert is decayed limestone and is found about a metre down. It is dug out and left over winter to be broken up by the frost. The big lumps of stone are used for the footings and plinth wall - known as the 'grumpling' -, the rest is mixed with straw and water and used to build the walls. No wychert building has been built since 1939, requiring our mainly volunteer team to re-learn skills that have largely been lost. The construction work was completed in 2012, but there is still a lot of internal work to complete, such as lime-hair plastering and distempering.'
 
'The other project we have on at the moment, is the re-roofing of our Iron-Age house. It was built in 2006 and was in dire need of a new roof. The old roof was removed, and we have constructed a new one using trees cut on site - mainly Ash, Oak and Cherry. In most reconstructions, sisal string is used to tie on the battens and thatch. For this roof the rafters and battens are tied on with Old Mans Beard and brambles, and we are using hazel rods tied to the rafters with willow to secure the thatch. The thatching straw is mainly spelt wheat, as grown in the Iron Age, and was grown locally.'
 
'Once the roof is finished we need to do some repairs to the wattle and daub walls, and the floor, but hope to have the building ready as soon as possible.'
 
The Chiltern Open Air Museum re-opens on 29th March 2013 and is located at Newland Park, Gorelands Lane,
Chalfont St. Giles, Bucks HP8 4AB. For enquiries telephone 01494 871117.