Chimney and hatch openings in trussed rafter roofs

TRADA image

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

Roof battensnavigation-arrow

Roofing battens are fundamental to a roof structure and are used in a loadbearing capacity. They are designed to carry the load of slated and tiles roofs as well as imposed loads caused by wind and snow. In addition, they may be required to provide a reasonably secured foothold for...

01/01/2012 |  Choose and Use  

Trussed raftersnavigation-arrow

Widely used for a range of building types, trussed rafters are an economical, versatile and straightforward solution to providing a roof to a building.

Trussed rafters are individually designed prefabricated structural components made from strength-graded timber members of the same thickness, joined together with punched metal plate connectors....

11/04/2017 |  Wood Information Sheet  

Standard bracing of 'Room in the Roof' (attic) trussed rafter roofsnavigation-arrow

This information sheet is an extrapolation of the standard bracing requirements given in BS 5268-3 extended to cover 'Room in the Roof' trussed rafters. All the information given here should be read in conjunction with the requirements of that standard.


  • Why brace trussed rafter roofs?
  • Bracing responsibility
  • ...

01/01/2007 |  Info from other organisation