Timber external doors

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An external door has a demanding role to perform and is expected to maintain its level of performance over many decades. It is mechanically stressed throughout its life due to opening and closing. Its inner face is subjected to the heated dry interior of the building, while the outer face is often exposed directly to the elements, unless protected by a porch or protective canopy. It is often installed into a building which has not yet dried out, yet it is expected to remain flat and maintain the designed door-to-frame gaps both during and after the drying out period.


The architect, door designer, manufacturer, supplier, installer, user and maintenance contractor form the chain of responsibility that leads to long-term satisfactory performance of timber external doorsets.


This Wood Information Sheet (WIS) discusses aspects of design and site practice which affect the performance of external doors.



  • Performance requirements
  • Timber for external doors
  • Design considerations
  • Finishes
  • Storage and installation


This Wood Information Sheet was revised in April 2019 and minor amendments were made following related British Standard updates.


For queries about this technical document, please get in touch with its authors via BM TRADA’s Technical Helpline on +44 (0)1494 569601 or email timberadvice@bmtrada.com.


A paper/digital copy of this Wood Information Sheet is available in the BM TRADA Bookshop, which also hosts additional specialist timber publications.

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