The key advantages of incising timber are:
- Improved penetration and retention of wood preservative. In BRE field trials incising spruce prior to preservative treatment doubled the uptake of preservative and appeared to double the service life of the treated stake.
- Porcupine incised products have a sympathetic, aesthetic look closely mimicing unincised timber. This is in comparison to the more aggressive North American incision patterns which have a less desirable visual appeal.
- The treatment produces a uniform penetration envelope that is quantifiable.
- Ability to demonstrate conformity with European Specification Standards.
- Improved durability of treated commodity.
- Reduced stresses in commodity (reduced checking of surface.)
- Reduced drying time (species dependent)
- Reduced risk of premature failure of treated timber and the potential benefit of reduced timber waste volumes.
- Consistent supply of material into potential end uses in the UK (e.g. highway fencing.)
|Example of typical North American incising pattern
with wider, less aesthetically pleasing blade incisions
|Porcupine incised post with aesthetically pleasing
incision pattern and high technical performance
|Criticism levelled at incising has been based on the reduction of bending properties. Research has shown that the modulus of rupture is reduced by 16% and the modulus of elasticity is reduced by 13% due to incising (Banks 1973).However, these initial strength loses are not significant for many end use applications and the increased performance of the product far outweighs the strength reductions.|