In some embodiments, a form assembly is provided with a form member facing an existing wall, to which sheathing panels are attached. The cavity created between the sheathing panels and the existing wall can be filled with a foamable, adhesive material which adheres to the sheathing panels and the existing wall and creates an adhesive connection between them. In some embodiments, the form assembly is vertically adjustable to facilitate the installation of multiple rows of sheathing panels. In some embodiments, the foamable, adhesive material is introduced in successive layers.