The History

Cefn Mably was originally a large country house and is situated just off the M4 motorway, between Cardiff and Newport in South Wales.

It is a Grade 2 listed building constructed by the Kemey family during the late 16th and early 17th Centuries, with major additions built by the Kemey-Tynte family in the 19th Century and E.S. Hall in the 20th Century. In 1923 the estate passed from private ownership to become a tuberculosis hospital until its closure in the 1980s.

In September 1994, a devastating fire rendered the building derelict. This state of dereliction continued to worsen over the next 4 to 5 years until Meadgate Homes, a South Wales based developer of homes of distinction engaged Davies Sutton Architecture to prepare a scheme to fully restore the whole property to a standard befitting its listed status. E. Turner & Sons, a Cardiff based Contractor and part of the Willmott Dixon Group, were taken on as Principal Contractor for the project.

The Project

M. Camilleri and Sons Roofing was asked to attend a series of meetings with the Principal Contractor and the Architect to discuss suitable roof coverings and details. One of the major problems to overcome was to provide materials on a like for like basis with the existing, which would comply with modern legislation and meet the requirements of Cadw (Ancient monuments in Wales).

Bearing in mind the condition of the building, most of the information could only be gleaned from black and white photographs. Various materials were proposed and presented

to Caerphilly County Borough Council, the consenting authority, and eventually Burlington Blue Grey Random Diminishing slates were chosen. Ridges and finials came from Redbank Manufacturing, timber battens and counterbattens from John Brash & Company and breather membranes were supplied by Dupont. All the leadwork for the chimneys, dormers, box gutters, etc. was included and was required to comply with Lead Sheet Association recommendations.

One of the problems encountered by Camilleri Roofing was the long term roofing programme of some 34 weeks and the rolling availability of work. Slates were ordered, brought in, sorted to size and holed in the traditional manner. However, one of the Architect's requests was that, irrespective of time scale, they wanted approximately the same schedule of diminishing courses at the end of the project as they had at the beginning.

This problem was further exacerbated by close mitred hips around the whole project and the fact that some of the roof slopes were as much as 10 degrees different to the opposite sides. This took an enormous amount of planning to ensure sufficient slates of various lengths were available throughout. Then, in addition to this, the architect asked for Camilleri Roofing to ensure that the coursing on the main roofs also carried around into the dormers. Therefore, if the dormers were in the middle of the roof and lined up with for example a slate of 325mm, the eaves course of the dormer had to be 325mm and if it was on a change over course then the dormer had to change over as well.

After approximately two weeks of planning, a sample panel of some 18m2 was constructed for approval by the Architect. This was to take into consideration the diminishing courses side laps and the quality of work.

By the end of the project, working under the strictest Health and Safety regulations (without a single recorded incident), over 2,200m2 of random diminishing slates were laid together with approximately 220m2 of leadwork.

We believe the standard required and achieved by our tradesmen on this project is by far in excess of that seen in a day to day working environment. In today's profit-led construction industry we found most roofing contractors asked to quote alongside us on this project would not undertake such a time consuming job, finding easier and more lucrative contracts to carry out.


Nearly 70,000 slates were laid, of which nearly 6,000 (some 8%) were cuts. The average workforce throughout the project was six men - the project commenced in August 2000 and was completed in February 2001.

On practical completion there wasn't a single item of snagging and on handover some 12 months later there were only 6 slates to replace (which we like to think were broken by others!)

This project was recognised by the National Home Improvement Council and we were subsequently awarded the N.H.I.C. workmanship award for 2002.

Click on the pictures below for a closer look.