The History

The Dyffryn estate, which dates back to 640AD, was formally known as the Manor of Worlton when King Judhail gave the estate to Bishop Oudoceous of Llandaf.

The name was changed to Dyffryn St. Nicholas in the 18th century when the estate was sold to Thomas Pryce.

In 1891 the estate was sold to John Cory and it was he who built the present house in 1893. It was also Cory who commissioned the design of the gardens to complement the house, which have developed into what we see there today and have been listed as Grade 1 in Cadw's register of landscapes, parks and gardens of special historic interest in Wales.

The Grade II* listed house, which was leased to the Glamorgan County Council for 999 years in 1939, was the subject of £1m of renovations in 2007 and this work included re-roofing entirely, for which we were appointed as specialist sub-contractor.

The Project

In order to assess the roof structure beneath and to carry out any necessary remedial timberwork, an over-roof was provided to the entire building. The existing slates (a mixture of Penrhyn and Ffestiniog), battens and horse-hair felt was then stripped from the roof in totality.

The 980m2 roof was renewed with new Ffestiniog Welsh slates in a 500 x 300 size - in fact some 16,000 slates were required. As the roof was close-boarded, we were required to introduce counterbattens in order to permit a drape in the underlay. A standard breather membrane, 50 x 25 sawn fir battens and slate build-up then followed.

The 70° mansard roofs were finished with slates fixed directly to the close-boarding, which is actually a traditional Scottish roofing practice. Other features included purpose made lead vent terminals (which we actually manufactured) and a lead clad bat access dormer. The roofing works were carefully timed to avoid the disturbance of roosting bats.