When constructing a new or replacing an old roof, the two most important choices for you, the client, are (1) the quality of the tradesman appointed and (2) the quality of the material utilised for what, in many cases, will be a roof to last a lifetime.
Older properties that are Listed, or within a Conservation Area, will be subject to planning restrictions and early consultation with your local planning authority is recommended where a change of material is sought.
In many cases the planning authority will insist on a 'like for like' material replacement.
In February of 2014, Bain and Irvine Ltd. completed a full strip and re-slate of a domestic property in the Colinton Conservation Area of Edinburgh, wherein a proportion of the original 'Ballachullish' slate was re-used along with perfectly matched second-hand reclaimed Ballachullish slate.
Best quality second-hand Scotch slate is not always readily available, however, and the use of an alternative material may be necessary.
Alternative slate types that are available, and acceptable to Historic Scotland, are: 'Burlington Blue/Grey', 'Spanish Cupa Heavy 3' and 'Welsh Greaves Port Madoc'.
All of the above slate types adhere to the stringent guidelines/tests for absorption (A1), appearance (T1), carbon content (S1) and other general characteristics ensuring a slate will withstand the test of time.
Any slate type not adhering to the above guidelines, should not be utilised in Scotland where weather, at particular times of year, could be considered extreme.
Weather conditions in Scotland also determine the need for adequate fixing methods, and in this regard, training and supervision are of the utmost importance. Graeme Millar, Managing Director of Bain and Irvine Ltd., recently produced Technical Bulletin TB43 for slate fixing, approved by the 'National Federation of Roofing Contractors' (NFRC) and to be adopted by the 'National House Building Council' (NHBC) in new construction where reclaimed Scotch slate is to be utilised.