ROOF SLOPE

 
   When making a determination of which roofing product best suits the requirements of your project slope is certainly important to take into consideration.  Slope (or also stated as "Pitch" within the roofing industry) is defined by the rise of the roof divided by the run.  For instance, if you had a 12" horizontal run with a 6" rise then the slope is referred to as a 6/12.  Utilizing this method you can determine any typical roof slope which will range from the 0/12 of a flat roof to the 21/12 of a mansard style roof.  Once you have determined the slope of your roof this will indicate your roofs ability to effectively shed water from the deck surface and dictate the limitations of certain roofing products available on the market today. 
   Composition shingles which are most commonly used rate for installation of no less than a 3/12 slope and can be installed above a 12/12 pitch if certain steep slope application methods are performed related to additional fasteners and spot adhesive under each roof tab at the time of installation as the specific manufacturer requires.  The slope limitations are usually labeled on the packaging of the product or should be readily available online at the manufacturer's website.  To many times to count on a yearly basis we observe and or replace badly leaking low sloped roofs with horrible decking and rafter damage due to ill-informed installers who apply composition shingles on homes and patios with slopes far too low for proper surface drainage with this product.
   If your roof slope is 0/12 - 2/12 then for adequate protection you will be looking at commercial roofing products such as E.P.D.M. (Ethylene-Propylene-Diene-Monomer) which, depending on the project size, is often installed seamlessly.  Other potential products for low slope application are Modified Bitumen, T.P.O., Tar & Gravel, and becoming more common is Elastromeric Coating Systems which also act as a radiant barrier with their white pigmentation.  Discount Roofing's experience recommendation of these products is Modified Bitumen on no less than a 1/12 slope and E.P.D.M. or Elastromeric Coatings for 0/12 - 3/12 for a long lasting resolution to your low slope roof issues.
     Metal roofing panels may be installed on roofs with a slope as low as 1/2 /12 if sealant is used on the panel side laps. If sealant is not used on the panel side laps, then the minimum roof slope is 3/12.  Regardless of the roof slope never allow your metal or tile roof to be installed over living area without first applying and elastromeric underlayment.  An Elastromeric Underlayment is, for lack of a better description, a sticky backed felt paper with a self-sealing ability.  The elastromeric within this product actually closes around the penetrating fasteners and if installed properly can act as a roof system under your finished product for added protection and peace of mind.
   Hopefully the explanation above for measuring roof slope is helpful in your decision of what roofing products are best suited for your application.  If you have unanswered questions about how to determine the slope of your roof or about the products that we install feel free to visit our website at www.Discount-Roofing.com or contact Discount Roofing at 936-756-1170 .  Emails can be directed to eric@discount-roofing.com .  

Eric Powell / Discount Roofing 2012
936-756-1170