In the current study, the authors discuss a homogeneous hygrothermoelastic slab of thickness 2h sandwiched between two similar elastic half-spaces. The hygrothermoelastic slab is subjected to a mechanical source of constant magnitude. The source is applied along the interface of the slab and upper elastic half-space. The analytical expressions of the components of displacement, stresses, moisture concentration, and temperature field are obtained by the normal mode analysis technique. The analytical results are used to solve the problem numerically by taking a wood slab as a porous material. The graphical results elaborate the effect of the thickness of a slab on the physical quantities. The problem of hygrothermoelastic layers sandwiched between elastic half-spaces is a novel idea, which finds its applications in various engineer ing models. The results found are interesting in the context of the problem. It is observed that the thickness of a hygrothermoelastic slab affects the deformation in the medium and the values of physical quantities decrease with an increase in the thickness of the slab.