Timber Eaves

Eaves detail, showing the junction between a standard timber-framed wall and timber roof construction. The roof is a warm construction, with insulation laid above the main structural elements (in this case prefabricated timber joists). An AutoCAD file in 2004 format is available to download at the end of the article. 

Timber eaves.jpg

  1. Standing seam copper covering, fixed to roof deck with copper cleats hidden within the seams
  2. Breathable sarking membrane (e.g. Kingspan Nilvent) - the waterproofing layer in the roof
  3. 9mm WBP (weather and boil proof) plywood
  4. 9mm fibre cement soffit board
  5. 100mm rigid insulation
  6. Copper drip
  7. Copper gutter
  8. Solid copper gutter bracket
  9. 50 x 100 x 1500mm softwood sprocket rafter at 400mm centres, fixed to top of main timber joists
  10. 19 x 200mm painted softwoodfascia panel
  11. Insect mesh fixed to underside of sprocket rafter
  12. 12.5mm WBP plywood
  13. 302mm deep softwood joist at 600mm centres (e.g. TJI PRO 350 series), fixed to joist hangers, hung from eaves beam
  14. 133 x 200mm glulam eaves beam
  15. Timber-framed wall construction:
  • 12.5mm plasterboard
  • Vapour control layer (e.g. Tyvek SD2)
  • 150 x 50mm softwood frame, with full-fill warmcell insulation
  • 9mm sheathing ply
  • Breather membrane (e.g. Tyvek Housewrap)
  • 24 x 38mm vertical battens and horizontal counter-battens
  • Lime render on expanded metal lath


Source: professional architect's drawings from real-life project 

Additional downloadable files

Timber framing - eaves.dwg
Submitted by Nick Howlett82 Articles
Published on Wednesday 2 September 2009View Profile