One of the most important parts in a building to insulate are bathrooms and lavatories. Nowadays they tend to be more spacious, hence a suitable and proper insulation is needed. The thickness of the XPS boards may change depending on where they are being installed. The bathroom insulation consists of different parts. The main structure is first established using the Light Steel Framing (LSF) with the XPS boards screwed with rawlplugs on top. Then a thin layer of cement is either laminated or applied on top of XPS insulation boards. The final layer is the desired tile, wood or any material due to the application which is applied using special adhesives and mastic. All the other mechanical equipment and utilities are installed inside the LSF.