CoverageLength: 300mm. Half round ridgeThey can be dry fixed, mortar bedded only or mortar bedded and mechanically fixed. When ridge tiles are mortar bedded & mechanically fixed, use clamping plates and woodscrews, complete with neoprene washers and foam grommets. A 6 mm diameter hole should be carefully drilled centrally in each ridge tile.A Block End Half Round Ridge Tile must be used at the verge when using the Cloaked Verge or Ambi-Dry Verge System.