For the lining of the inside of the attic there is a large selection of various materials. The most suitable are the following materials: 1. Gypsum cardboard sheets (GKL). Experts consider it the most suitable for the internal skin of the attic. GKL has the property of both absorbing excessive moisture, and give it back to the external environment (plays the role of a kind of humidity regulator). Another positive quality is that it is not a fuel, and with its help you can build curvilinear surfaces. GKL is also easy to process, but nails are poorly held in it.