Tiles for the valley must be cut away from the roof to prevent dust from blocking up the pours of the breathable membrane and to avoid damage to the roof.

Tiles should be cut neatly to the valley former avoiding the use of small pieces.

Use (large) tile and a half where necessary.

Valley former should extend a minimum of 50mm across the gutter.

Saddles are required to be placed at the top of every valley.

Lead or a proprietary product acceptable to the pre-formed GRP valley manufacturer can be used.

Proprietary verge clips should be used at gables when required e.g. with ‘Forticrete’ SL8 roof aLead used to form the interface of tiles and valley.

Lead apron provided to the extended lower section which is terminated underneath the dry verge of the adjoining roof.

A creased edge is provided to the lead at the small verge to guide the rain water into the gutter.

The foot of the dry valley must be sealed to prevent vermin entry if it extends wider than 10mm, in conjunction with the dry fix system.

Tiles for an open valley must not be cut in-situ. Individual tile should be cut away from the roof and bedded with valley pointed using the same mortar.

Small cuts must be secured to the adjacent tile using proprietary clips.

Intersection between valleys and roofs must be transferred using a lead soaker.

Valleys in slated roofs do not need to be pointed providing vermin entry is prevented.

Under cloak should project the gable by 38mm – 50mm when using plain tile or slates.

30mm – 60mm when using interlocking tiles.

A minimum of 100mm depth of concrete when compressed with the mortar struck and pointed when green using the same mix.

Pointing should be neat without excessive mortar on the tiles or slates.

Stepped flashing must be installed into the brick joint below the stepped cavity tray.

Where slates, plain tiles and flat interlocking tiles are used, soakers or a secret gutter should be installed.

Brick joints can be sealed with an appropriate lead sealant.

Masonry chimneys projecting through a roof will sometimes require 2 cavity trays to link in with the apron and box gutter.

The apron would be installed below the lower tray, the tray will be formed downwards at the apron and upwards on any elevation which enters the roof space.

Stepped flashing is the installed but not linking in with a stepped cavity tray.

The box gutter is installed below the upper tray. In this area, all side of the tray would form downwards.

Flashing to dummy chimneys will be installed as per the manufacturer’s guidelines.