| On all roofs, it is absolutely required that a protective bitumen membrane or other waterproof underlayment be used to help ensure the roof is watertight. The most critical problem that can occur with clay tiled water shedding roofs is the localized incursion of water. Water can migrate through the joints of the tiles through capillary action, rain driven in by high wind or in temperate climates runoff or ice-damming. As a consequence of this possibility, a high quality underlayment is critical to ensure the integrity of the roof. Underlayment may be of a self adhesive type or torch on type ( heat induced bonding of underlayment sheets). TAP recommends the use of a 3mm thick felt underlayment. It is to be noted that Roofing Felt should meet or exceed ASTM (American Standard Testing Method) Standards D226/D2626. |
