What are the patterns on my natural slate roof?
As a natural product, roofing slate often has slight colour variations and changes in the direction of sediment layers laid down before the rock was formed. These will commonly only show up on a newly installed slate roof under certain lighting conditions – for example when the sun shines from a particular angle.
Whilst you may be able to see the patterned variations on installation, after a few months natural weathering of the slate will weather out the changes and they will disappear.
A well selected natural slate roof with slates that have been properly graded and sorted on site will have an even appearance which it will maintain over many decades.