kattohuovan
Kattohuovan is a Finnish term referring to roofing felt, a common building material used for waterproofing roofs. It is typically made from a base material, such as fiberglass or polyester, which is then saturated with bitumen (asphalt) or a similar petroleum-based compound. This saturation process gives the felt its water-resistant properties.
Kattohuovan is often used as an underlayment beneath more durable roofing materials like shingles, metal roofing,
The installation of kattohuovan usually involves rolling out the felt over the roof deck and securing it