One of the most important elements of any roof is the underlay. This part of your roof asset protects and seals the wood beneath, and stops the tiles above from sliding around; helping it to keep secure.

Roofing underlays come in two different varieties, along with a number of slight variations in these varieties. These are tar paper and felt paper. Felt paper is also known asphalt felt paper and roofing felt, and it is known for:

Felt paper is a mat of fibreglass or sheet of paper which is impregnated with bitumen, otherwise known as asphalt. This turns the material into a sticky and waterproofing layer, ideal for keeping your roofing materials in place and as an added layer of water-proofing to prevent water damage.

Tar paper is what preceded felt paper, and follows pretty much the same creation process, except with tar rather than asphalt. It is currently used far less than felt paper, essentially because it is an inferior product. It is lacking in part because it is far less resistant to heat, sunlight and wind, and as a result its lifespan tends to be considerably lower than the alternatives.