The following types of board have been tested:

  • SAUERLAND stile & rail HVA-650 kg/m³
  • spruce: vertical annual rings 
    spruce: horizontal annual rings
  • meranti
  • beech

Climate Test

The samples have been exposed to 80% rel. humidity until the moisture had increased by about 3 %.


SAUERLAND stile & rail material

  • low swelling / shrinking due to structure of ‘vertical grain’ 


  • great variance of swelling and shrinking
  • vertical annual rings : variation twice as high as of samples with horizontal rings

Consequence for door construction

Components within a door use to have lower moisture content than those exposed to open humidity. 

This fact should especially be considered for :

  • stile reinforcements
  • second rails
  • lock blocks


All components inside the door should have a structure of ‘vertical grain’.