The paper describes an approach to model glue laminated timber (GLT) made of pinewood (softwood), taking into account damage processes in timber and adhesive layers. An example of a pre-cracked beam has been presented. Obtaining necessary material properties has been supported by several finite elements models (FEM), laboratory tests and a wide literature survey. The authors have taken into consideration an orthotropic material with damage for timber lamellas and isotropic traction separation law for bonding layers. Both plane stress CPS8R and COH2D4 finite elements from the Simulia ABAQUS system or mesh density, used in the numerical analyses, have been carefully chosen and tested. The GLT beam model has been verified on the basis of several values, using two types of testing techniques—MTS 809 machine measurements and digital image correlation (DIC). Additional results revision has been provided by measuring a crack shear displacement (CSD), using the original laboratory test setup by the authors’ idea. Finally, some conclusions and introductory recommendations for modelling a glue laminated timber in a plane stress have been formulated. The paper is a part of a wider research on timber-polymer composites, which is still under development.