Modified wood products

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Defined as wood which has been treated with a chemical, biological or physical agent to enhance its performance, modified wood products (MWPs) are an area of almost constant change, with new techniques being developed all the time.


The seemingly unrelenting changes and improvements in MWPs make the need for specifiers to be kept abreast of developments of paramount importance.


This Wood Information Sheet provides readers with a guide to the benefits of modifying wood, how to select and specify modified woods for a particular use and how woods are modified and the significance of specifiers.



  • Types of modified wood product
  • Benefits of modified woods
  • Selecting modified woods
  • Principal processes for modifying wood
  • Quality assurance process
  • List of manufacturers consulted
  • Further reading


This Wood Information Sheet was revised in October 2021. The updates are as follows:

  • Change to Tables 1 and 2 and throughout the text because no impregnation modified woods are commercially available in the UK.
  • Table 3 has been removed because the information is constantly changing so readers should check with manufacturers own websites.
  • Redwood is now referred to as Baltic redwood / Scots pine throughout.
  • Information added on acetylated wood and its sustainability credentials.


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


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

Suggested Reading

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List of Wood Information Sheetsnavigation-arrow

This document contains a fully comprehensive list of all the most up to date Wood Information Sheets (WIS) published by BM TRADA. Available to members for free or non-members from £12.00, these Wood Information Sheets provide technical guidance related to almost every timber topic under the sun.



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