Chimney and hatch openings in trussed rafter roofs

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Unless subject to special design, hatches and chimneys should be accommodated within the standard spacing between trussed rafters.

This Product Data Sheet is intended to give some ideas on how to frame around openings in trussed rafter roofs. It must be stressed that these are typical solutions to framing openings since each roof will have its own characteristics.


  • Fig 1: Framing around chimney
  • Fig 2: Cross-section through chimney
  • Fig 3: Chimney or hatch opening up to 2 x normal truss spacing
  • Fig 4: Chimney or hatch opening up to 3 x normal truss spacing
  • Special detail for low pitched roofs
  • Fig 5: Framing around hatch
  • Fig 6: Cross section through hatch
  • Fig 7: Supporting purlins in low-pitched roofs

Suggested Reading

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