KENDAL'S historic Castle Dairy could be much older than firs thought.

The results of tree-ring dating of roof timbers at Castle Dairy on Wildman Street has revealed that the current form of the building is at least late medieval in date – and that the original structure may date back even earlier.

This contradicts some earlier theories that significant sections of the building were added much later and the new evidence is being described as a ‘hugely significant’ by archaeologists.

Recent re-roofing work at the Grade I listed Castle Dairy allowed experts to carry out the tree-ring dating of the roof timbers, which are otherwise very difficult to access.

As the rings in a tree (typically oak) grow they form a pattern, similar to a barcode, which is created by the variations in the year’s climate.

This can then be matched to other sequences that have already been dated, allowing the precise date at which the timber was felled to be calculated.

Experts say the roof timbers at Castle Dairy gave very good samples, all of which gave a felling date in the late 1480s, showing that the building must have taken approximately its current form by that date.

Dan Elsworth, director at Ulverston-based Greenlane Archaeology Ltd, who managed the tree-ring dating project, said: “This is hugely significant in understanding the history of the structure.

“It confirms that the building is at least late medieval in date. In addition, it suggests that it may have even earlier origins as it is likely that the roof of the 1480s replaced an earlier one.

“It also shows that Anthony Garnett, who is known to have acquired the building in the 1550s and whose family owned it for about 200 years, did not construct any significant sections of it, as has been previously suggested.’’

The tree-ring dating was carried out by Nottinghamshire-based specialist contractor Ian Tyers and the work was funded by grants from the Cumberland and Westmorland Antiquarian and Archaeological Society, the Kendal Historical and Archaeological Society and Kendal Civic Society.

The re-roofing project and earlier renovation work had already produced some interesting finds that shed even more light on Castle Dairy’s past.

Several elaborate marks were found carved onto the roof timbers made by the original carpenters who worked on the building, providing evidence for the order in which the building was constructed.

Some of the trusses over what was originally the main hall were also blackened by soot, suggesting that the ground floor was originally open to the roof and the fire was positioned in the middle of the room, in typical early medieval fashion.

Cllr Chris Hogg, SLDC’s portfolio holder for Culture, Arts and Events, said: “This re-roofing project has allowed us the opportunity to carry out date-testing of the roof timbers, which has revealed some exciting new evidence about Castle Dairy and gives us a far greater insight into this important building’s history.’’