Slate details - Keswick, Borrowdale

These slate walling details caught my eye on a recent walk in the Lake District, Keswick. 

I would guess this type of slate to be mixed Westmorland green slate, laid randomly with vertical slate coping stone, roughly cut and split.

Slate walling can be seen across the Lakes. Slate walls are known for their durability, they require low maintenance, are rarely affected by adverse weather conditions and provide a natural aesthetic.

Slate walling is ideal as retaining walls between levels- the slate photographed to the left is an example of this, retaining an ascent from Derwent waters edge up to road level. 

The slate used here is lightly to be hand-crafted using chisel and mallet in the aged traditional way of splitting. The finish is slightly textured riven surface, with the ends and tops sawn. 

Splitting is a specialist process which splits the slabs into the correct thickness whilst maintaining the materials integrity. The slabs are split where a natural break occurs (cleavage) in the slab to give it a clean, straight split. 

The slate is then ready to be trimmed to a specific length for its chosen purpose. Traditionally this was done by hand but nowadays machines are used to trim the slate to the perfect measurements for installation. 

The wall is likely to be a dry stone wall- no mortar in joints. Vertical coping stones are likely to be secured with a dry lime mix mortar to prevent them from being dislodged. 

It is clear that the slate steps will be secured with dry lime mortar due to heavy footfall.