Church roof over 500 years old, study reveals

A SCIENTIFIC study has confirmed a "truly spectacular
find" that proves oak timbers from a church in a heritage town are over
500 years old.

The timbers from the roof of the Holy Trinity
Church of Ireland in Fethard, Co Tipperary, were sampled in June and
examined at Queen’s University in Belfast.

It is now the only medieval roof in Ireland to be accurately dated.


David Brown, of the university’s school of geography, archaeology and
palaeoecology, said analysis of the tree rings from the roof revealed a
felling date of 1489, plus or minus nine years.

The church
itself is an important feature of the walled town in Fethard and was
originally built in the early 13th century, but now consists mainly of a
mid-19th century remodelling.

However, concealed beneath the
Baltic pine roof from about 1800 and above the plastered Victorian
barrel-vaulted nave is an ancient arch-braced, clasped purlin oak roof
some 24 metres (80 feet) long.

Architect Margaret Quinlan made
the discovery of the roof, which can only be accessed through a small
hatch leading from the belfry into the roof cavity.

Under
licence from the National Museum and the Minister for Arts, Heritage and
the Gaeltacht, 10 samples were taken from the roof last June and
analysis was commissioned by the Fethard Historical Society and
part-funded by South Tipperary County Council.

All the samples
returned a close match in growth pattern, which enabled the team in
Belfast to assemble a chronology of 77 years for the batch. This
chronology was then compared with the master chronology held at Queen’s,
which showed the samples were growing between 1384 and 1460.


In the absence of bark and although much of the sapwood was missing, the
team was able to come to a conclusion as to the felling dates of the
roof wood.

Back then, timber frames of this kind were erected
"green" for ease of assembly (before the wood hardened and became
difficult to work) and so the assembly and raising would have taken
place almost immediately after the felling date.

David Brown
estimates that the trees used in Fethard were immature at the time of
felling — perhaps less than 100 years old — and derive from the first
regeneration of oak trees planted after the Black Death of 1348.


Mr Brown described the find as "a truly spectacular result for an
Irish roof and for dendrochronology", the science of tree-ring dating.


Oak-framing practitioner Paul Price identified "see-sawing" marks on
one of the collars, indicating the wood was converted (from tree to
beam) using a long-lost medieval technique. 

This would appear to be the
first time that see-sawing has been identified in Ireland.

Source