The slate tiles that I bought for the shed, were sourced from Jewsons. There are four classification of slate tiles: Excellence, Specification, Commercial and Economy.
Generally I would advice choosing Specification and Excellence. These tiles allow a flatter finish and less potential wastage. I am pleased with the result that I achieved. This was accomplished through significant sorting of the tiles into thickness and flatness first. Secondly positioning them and then repositioning them on the roof to get the best fit. This took more time which could be saved by using a more expensive classification. I managed to achieve the result that I wanted with very little wastage in this case, but the sorting time was significant.
A slate roof is a heavy, durable roof with and will last for many more years than a felt roof which has a lifespan of typically around 5 years. The structure that I built the roof on was 400mm centred solid roofing joists to ensure that the weight could be taken. I checked for movement or bowing afterwards and the wooden structure had not altered. To reflect the lifespan longevity that the tiled finish provides, I triple layered the insulation on the roof. So I put in place a layer of breathable membrane, a layer of felt – battoned on top and then slate tiled. This ensured that the whole structure has a totally water tight finish.
To finish off the look I used a dry fixed ridge cap requires no concreting. This supports the low maintenance requirements of the roof for many, many years. It also is attractive to the eye. As this building is visible from our lounge window, that is of primary importance for a happy relationship!