Roof Tile Underlayments:
Roof tiles are primarily decorative. The waterproofing is done by the tile underlayment membrane. Most roofing contractors still use the traditional hot mopped 90 pound paper which is an inferior product that we know lasts between 15 to 20 years. A brand new 90 lb. membrane tears like a regular piece of paper. Roofs with 90 pound paper will experience leaks after about 15 years first around all the metals which are the valleys, drip edge, vents and flashings. As the paper becomes fragile, the thickness of the metal, breaks the seal and the leaks start to occur. Then, these roofs will experience leaks in rest of the roof which we call the field. After attempting to repair a few of these leaks, the owners realize it’s a losing battle and then end up replacing the roof as the leaks keep occurring in new areas. If the 90 lbs. paper is so fragile brand new, you can imagine after about 15 years of scorching heat, it just crumbles on its own. The sooner you replace these roofs when the leaks start occurring the better as you are only buying time and putting good money into a bad roof. Some contractors are now using a tile underlayment paper called Polyglass TU Plus, it sounds like a premium product, but it also tears very easily.
We use a tile underlayment membrane made by Owens Corning called Weatherlock which comes with a 30 year warranty. This membrane is a reinforced modified bitumen and you can try to tear it but you won’t be able to. It is self-adhered so no nasty and messy hot mopping is needed. By using this membrane you will get so much more value for your money. Instead of replacing your tile roof in 15 to 20 years, you will have a membrane that is guaranteed by a fortune 500 company for 30 years. The roof tile will basically last forever so it doesn’t make any sense to use an inferior tile underlayment.
Customers always joke with us that they don’t expect to even live that long. But think about it, if you don’t, you are leaving something of great value to your family and if you were to sell your house we will transfer our warranty to the new owner because we are so confident of this product. And if you do, the last thing you want to deal with is a new tile roof 15 to 20 years from now!
We used to install, and still do if requested, two other premium modified bitumen membranes called Tamko Awaplan and GAF Ruberoid but prefer using Weatherlock because of its value and superior warranty. We also use Weatherlock under metal roofs.