Decra Plus Top Edge Abutment Detailing

Top Edge Abutment- Un-ventilated or Ventilated
The correct way to install the top course of tiles and the top edge flashing is dictated by whether you are trying to achieve an unventilated or ventilated top edge detail. 

 
 
Universal ridge ventilator

Unvented
1. Ensure underlay/breather membrane is turned not less than 75mm up abutment.
2. Install 2-no. 50 x 25mm battens to support head of top course of 0.9mm gauge tiles.
3. Install top course of 0.9mm gauge tiles
4. Position 50 x 25mm batten, with Decra Sealing Strip attached to the underside, onto the head of the top course 0.9mm gauge tiles. Secure by nailing through tile
into batten below.
5. Cut and bend 0.43mm gauge top course flashing not less than 75mm up abutment.
6. Secure bottom edge of top course of tiles to top batten with Decra fixing nails.
7. Seal heads of nails with Decra Finishing Kit.
8. Dress lead flashing over top course flashing upstand and front apron area to form weathertight junction.

Tips on cutting and bending tiles

Vented with a Universal D Ridge Vent Filler
1. Cut the roofing felt back at the top edge to allow a 5mm continuous air gap at abutment. Fix two tiling battens 50 x 25mm side by side on both sides of ridge, using galvanised nails.
2. Cut tile and fix tiles close to the abutment and maintain air gap. Secure top course of tiles using 4-no Decra Plus nails/screws driven through the downturn nose of the top course into the battens.
3. Nail additional 50 x 25mm batten, with Decra ‘D’ Ridge sealing strip attached to underside, onto the tile in a position to suit the fitting of the top course flashing unit.
4. Cut and bend 0.43mm Decra D ridge to form a top course flashing unit with a front edge downturn of 40mm and a rear upstand of at least 75mm up abutment. Position top course flashing unit over the top batten and upstand edge of tile. Install universal
ridge/hip ventilators between the additional 50 x 25mm batten and front downturned edge of top course flashing unit. Fix top course flashing unit over the top batten by
nailing through its downturn into the face of the batten. Use 4-no Decra Nails vertically into batten and seal with Decra Finishing Kit.
5. Dress lead flashing over top course flashing upstand and over front apron area to form weathertight  junction.