Prior to insulate the walls of plasterboard, any problems with moisture penetrating must first be resolved. The insulation should not be used to cover or hide the moisture, but to prevent their formation. The insulation for the plasterboard walls generally constituted by one of several forms of expanded plastic material which must be at least 6 inches thick, up to a maximum of 10 cm. The actual thickness required will depend on the material used. The insulation panels are fastened directly to the wall with duct tape and other additional hardware sealants, to prevent any air leakage. Here’s how to proceed.

Before you begin, you must remove chandeliers, radiators and any pipes that pass through the walls to be insulated. In addition, we must also remove the baseboards and door frames, you probably need to be replaced on the new wall. The areas surrounding the windows must be isolated at the same time as well as the walls, to prevent condensation.


Attach a wooden or metal frame to the wall and fill it with fiber, mineral wool, which can be immediately plastered, and then is ready for installation. The mineral wool is less efficient than the rigid insulating panels, for this reason, the filling should be at least 12 inches thick. Instead of immediately applying the plaster, the frame can be covered with insulating panels, rigid, so as to obtain an insulation even more effectively and further reducing costs.

It is difficult to insulate every square inch of each plasterboard wall, and if some parts are not isolated there is a risk that can form condensation that may initially go unnoticed until the problem does not develop in a more obvious. This problem can generally be minimized by isolating the areas around the cavity of windows, doors and the edges of the inner walls.

Another simple and inexpensive solution to thermally isolate the drywall is to bridge the gap with expanding foam. Just buy a proper gun and a can of foam. In this case, leave a space of at least 2 inches so that the nozzle of the gun could penetrate the drywall.