UnderlaymentAn underlayment, or moisture barrier, is always used between your roofing material and your roof deck. Low-E is recommended on top of your moisture barrier and then your roofing on top of the Low-E. When using Low-E, in almost any application, you need a ¾” minimum space between the Low-E and the roofing or wall materials. More space is fine but for the best results the manufacture recommends at least a minimum air space be left above the Low-E. That said we know of a few contractors who are laying roofing, even asphalt roofing, directly on top of the Low-E insulation. At least one contractor claims that their tests show a 20 degree lower inside temperature between the roof area where the Low-E was applied versus where it was not used. To create the air space when using Low-E with Metal Roofing the manufacturer recommends placing furring strips, or battens, on top of the insulation and then proceed to lay the roof on the furring strips. The problem with this method is that your roofing material may be more fragile to walk on when raised in such a manner. Recommended Underlayment
FelTex™ is our recommendation for any solid deck system with a 2 ½ pitch or greater.There are a number of reasons we prefer this product over the common 30# felt product. Basically FelTex™ is a specially engineered fabric construction of high-strength, lightweight woven fabric. This results in a very strong and durable product which is also easy to handle. It is lightweight, wrinkle-free and resistant to UV breakdown. The engineered design of FelTex™ improves surface grip and clings to the roof deck. The no slip skid resistant coating and textured woven surface features contribute to a safer walking surface. Another factor we like is that you can dry-in your roof deck with FelTex™ and leave it exposed to the elements for up to 6 months with no deterioration. FelTex™ is 100% inorganic to prevent rotting and mold growth, and, it contains no asphalt. You get all of the above, plus,
a 25 year limited warranty
for very close to the same price. FelTex™ is definitely our choice. Insulated Metal Roofing
|
