Purpose Made Valleys

• Working Procedures
• Documents

Standard detail
Purpose made valley slates do not require nailing. Slate and slate and a half are required for cutting to obtain the correct side lap. Valley boards are not required.

Non-Standard detail
Special valley tiles can be supplied for roofs with unequal pitches.

Note: The maximum pitch differential is 10°.

1. Set out the roof on the shallowest pitch first, to correct batten gauge.

2. Place a slate on a batten on the shallower pitched roof and present a valley slate to it. It will be noted that the shallower pitched side of the special is the same length as the slate.

3. Present a slate to the steeper pitched side of the special (it will be noted that the special has a shorter edge than the slate). Ensure that the tail of the slate coincides exactly with the bottom point of the special, the position of the nail holes on this steeper pitched slate gives the batten line for the steeper pitched roof.

Splay Valley detail (mimum pitch 25°)
Where angles on plan are other than 90°, valleys can be manufactured to suit. The splay valleys should be laid in alternate courses, with other alternate courses mitred, using slate and a half. No soakers are required. Splay valleys are fixed in the same manner as standard valleys.
Note: The height of the fascia is critical to the correct fitting of the purpose made hips it should be 20mm for Vented and 45mm for Non-Vented. (Height excludes 6mm ply fillet)