ISS is proud to offer the Contessa Natural Slate. This slate comes from Northern Spain, in the heart of the historic slate producing areas.
It is arguably one of the thinnest slates available within the UK market to date. In addition, it is a very flat and uniform slate, which means minimal sorting and grading needed when setting out the roof and finally laying and fixing the slate.
The Contessa is a blue/black slate which can exhibit some visual pyrite, this pyrite is inert and will not effect the performance of the slate as a water tight roof covering. The slate offers a smooth face with neatly dressed edges.
The Contessa Commercial is available in a 4mm thickness.
Commercial Grade slates are of a high quality and good selection, they will require slightly more sorting and grading prior to fixing than other grades, but once done Commercial-Grade slates offer a cost-effective solution that will still achieve a flat, uniform appearance on the roof.
Test results: The ISS-39 slate boasts a W-1, T-1, S-1 rating, meaning it conforms and surpasses all the top UK tests for water absorption, thermal cycle resistance and sulphur dioxide exposure.