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Top Edge Abutment Detailing

 

Top Edge (Classic, Decra Stratos, Noxite and Oberon Tile)

Unventilated top edge abutments are generally formed with a 75mm tile upstand, covered with a lead flashing.

Ventilated top edge details are generally formed by incorporating a Decra Top Course flashing and appropriate ridge ventilator into the design (see drawing and installation guidance below).

Decra Classic - Top Edge Abutment - Detail from drawing DTSE061

Applies to Classic & Noxite – Similar general principles of construction also apply to: Decra Oberon and Stratos.

NOTE: A different arrangement than above is required for Decra Plus tile, using a 0.43mm gauge top course flashing, read more.

  

Installation Guidance - Decra Classic, Noxite Tile systems only.

Top Edge Abutment- Un-ventilated or Ventilated

The correct way to install the top course of tiles and the ridge tiles is dictated by whether you are trying to achieve an unventilated or ventilated top edge detail.

NOTE: Be aware there is more than one type of top edge ventilation system.

D ridge vent filler

Universal ridge ventilator

Top Edge Abutment - Un-ventilated

  1. Ensure underlay/breather membrane is turned not less than 75mm up abutment.
  2. Install intermediate batten to secure top tile course close to junction with abutment.
  3. Cut and bend tiles not less than 75mm up abutment.
  4. Secure tiles to top batten with Decra Fixing Nails.
  5. Seal heads of nails with Decra Finishing Kit.
  6. Dress lead flashing over tile upstand and front apron area to form weather tight junction.

 

Top Edge Abutment - Ventilated Using A D Ridge Vent Filler

  1. Cut the roofing felt back at the top edge to allow a 5mm continuous air gap at abutment. Fit two battens side by side on both sides of the ridge using galvanised nails.
  2. Cut, bend up and fix tiles close to the abutment and maintain airgap. Place the Ridge Vent Filler on the top course of tiles. Position it so that, once installed, its lower edge will fit tightly against the downturn of the Decra top course flashing. Lay a batten, not exceeding 50 x 25mm, into the tray of the Ridge Vent Filler and secure by nailing through the Filler and tile into the battens on the underside.
  3. Cut and bend Decra top course flashing to form a turn up of at least 75mm up abutment. Fix Decra top course flashing over the top batten by nailing through its downturn into the face of the batten. Use 4-no Decra Nails.
  4. Dress lead flashing over top course flashing upstand and over front apron area to form weather tight junction.

 

 

Top Edge Abutment - Ventilated Using A Universal Ridge Ventilator

  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 approximately 10mm back from abutment, using galvanised nails. Fix an
    additional 50 x 25mm batten on top of the rearmost of the two tiling battens, in a position to suit the fitting of the top course flashing unit.
  2. Turn back edge of the tile up to form 25–38mm upstand against the top tiling batten.
  3. Cut and bend Decra D ridge to form a top course flashing unit with a front edge downturn of 40mm and forming 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 upturned back edge of tile and front downturned edge of top course flashing unit.
  4. 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.
  5. Dress lead flashing over top course flashing upstand and over front apron area to form weathertight junction. 

 

 

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Installation Guidance - Decra Oberon Tile systems only

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

Top Edge Abutment - Un-ventilated

  1. Ensure underlay/breather membrane is turned not less than 75mm up abutment.
  2. Install battens so that top batten adjacent abutment supports bottom edge of top course tile.
  3. Cut and bend top course of tiles not less than 75mm up abutment.
  4. Secure bottom edge of top course of tiles to top batten with Decra Fixing Nails.
  5. Seal heads of nails with Decra Finishing Kit.
  6. Dress lead flashing over tile upstand and front apron area to form weathertight junction.

 

Top Edge Abutment - Ventilated 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 approximately 10mm back from abutment, using galvanised nails. Fix an additional 50 x 25mm batten on top of the rearmost of the two tiling battens, in a position to suit the fitting of the top course flashing unit.
  2. Turn back edge of the tile up to form 25–38mm upstand against the top tiling batten.
  3. Cut and bend Decra Oberon Top Course flashing to size and forming a rear upstand of at least 75mm up abutment.
  4. Position top course flashing unit over the top batten and upstand edge of tile.
  5. Install universal ridge/hip ventilators between upturned back edge of tile and front downturned edge of top course
    flashing unit.
  6. 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.
  7. Dress lead flashing over top course flashing upstand and over front apron area to form weathertight junction.

 

 

Installation Guidance - Decra Stratos Tile systems only.

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

Top Edge Abutment - Un-ventilated

  1. Ensure underlay/breather membrane is turned not less than 75mm up abutment.
  2. Install battens so that top batten adjacent abutment supports bottom edge of top course tile.
  3. Cut and bend top course of tiles not less than 75mm up abutment.
  4. Secure bottom edge of top course of tiles to top batten with Decra Fixing Nails.
  5. Seal heads of nails with Decra Finishing Kit.
  6. Dress lead flashing over tile upstand and front apron area to form weathertight junction.

 

Top Edge Abutment - Ventilated 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 approximately 10mm back from abutment, using galvanised nails. Fix an
    additional 50 x 25mm batten on top of the rearmost of the two tiling battens, in a position to suit the fitting of the top course flashing unit.
  2. Turn back edge of the tile up to form 25–38mm upstand against the top tiling batten.
  3. Cut and bend Decra D ridge to form a top course flashing unit with a front edge downturn of 40mm and forming 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 upturned back edge of tile and front downturned edge of top course flashing unit.
  4. 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.
  5. Dress lead flashing over top course flashing upstand and over front apron area to form weathertight junction.

 

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