The experimental data on the properties of Silver birch (Betuel pendula Roth.) wood in relation to cambial age are summarised in 8 Excel files. But-end logs were used to prepare the samples for examination, and the examination covered the wood from the pith up to a cambial age of 30 years. Each file contains data worksheets and a 'Description' worksheet which provides a concise description of the methods used to obtain the data and the abbreviations used throughout the file. The files contain the following data: Annual Rings.xlsx – width of annual rings ; Chemical Properties.xlsx – content of extractives and Kürschner-Hoffer cellulose, FTIR spectra and crystallinity index of the cellulose, and pH of wood water extracts; Contact Angles.xlsx – contact angle data determined on the radial and tangential surfaces; Density.xlsx – dry density determined for samples representing juvenile and mature wood; Dimensional Stability.xlsx – data on wood swelling in axial, radial and tangential direction as well as swelling anisotropy for samples representing juvenile and mature wood; EMC.xlsx – equilibrium moisture content at RH 40 %, RH 60% and RH 80%; Fiber Dimensions.xlsx – length and width of earlywood fibers of every second annual ring. Vessel Proportin.xlsx – proportion of the vessel area determined for every second annual ring.