# Best material for a 3:12 pitch roof extension?



## Nittany (May 25, 2012)

It is time for a new roof for my L-shaped Ranch house. We have a hip and valley roof. In the L-shaped portion we have a patio that we wish to extend a roof over. The greatest pitch we can get over the roof extension is a 3:12 pitch. The remainder of our house has a 5:12 pitch and we intended to use IKO limited lifetime asphalt shingles. For the 3:12 portion, should we continue to use the shingles? or in order to avoid ice daming, leaks, etc. on a borderline low pitch roof would we be better off using a different material? We live in cold, rainy, snowy, windy Cleveland Ohio. Help?


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## tinner666 (Mar 14, 2005)

No shingles. Either use .060 reinforced EPDM, or a 3-4 ply SBS modifed roof with a granulated cap-sheet that closely matches your shingle color.


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## seeyou (Dec 12, 2008)

Iko's are not sold locally, but all other manufacturers that I'm aware of warrant installations down to 2/12 with special underlayment considerations. May not be the best solution, but we've done it locally for years with no problems. Our winter weather is not as extreme as yours is either. And as with any material, the key is proper installation execution.

edit: Hey Frank - this is my 666th post on this forum.


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## bcdemon (Jul 12, 2010)

Something you should know about IKO shingles:
http://www.iko.com/shared/residential/installation/8TTEFS-2012-01_8.5 x 11.pdf
(NOTE: IF THESE [underlayment] PROCEDURES ARE FOLLOWED, SHINGLES APPLIED TO SLOPES 3:12 TO 4:12 WILL BE WARRANTED FOR THE FULL WARRANTY TERM FOR THE SHINGLE. _*SHINGLES ON SLOPES 2:12 TO 3:12 WILL BE WARRANTED FOR 12 YEARS*_.)

On that note, have you looked into Certainteed shingles?


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## tinner666 (Mar 14, 2005)

FWIW, I based my reply primarily based on their location.


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## Windows on Wash (Aug 30, 2011)

Warranty or otherwise, 3:12 is not anywhere near ideal for an standard installed asphalt.


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## Gary in WA (Mar 11, 2009)

As post #4 brought out some of the warranty depends on the specific IKO shingle chosen, if it will pass on the 3/12 or not; 

"The Limited Warranty terms set out in this document only apply to Shingles installed on roof slopes of 4 in 12 (1:3) and steeper. The limited Warranty Period for Shingles installed on low slope roofs (i.e. those with a slope of less than 4 in 12 (1:3) and down to 2 in 12 (1:6)) is 12 years, and will be prorated for material only (with no Iron Clad Protection coverage) at an annual reduction rate of 8.33%.* If certain application procedures are followed as detailed in the application instructions printed on the Shingle wrapper, the regular Limited Warranty may be available for slopes between 3 in 12 *and 4 in 12 (1:4 and 1:3). Please see the product packaging or visit www.iko.com for application procedures and instructions for your Shingles, as certain Shingles may not be suitable for use on slopes below 4:12." Bold is mine. From: http://www.iko.com/shared/residential/warranties/IKOUNIIndWarranty.pdf

Both IRC and IBC accept low-slope roofs if extra underlayment is applied; http://publicecodes.citation.com/icod/irc/2012/icod_irc_2012_9_sec005_par003.htm

IBC; http://publicecodes.citation.com/icod/ibc/2009/icod_ibc_2009_15_sec007_par003.htm

Ice dams are not caused from the slope of the roof; http://bct.eco.umass.edu/publications/by-title/preventing-ice-dams/

Dam ice dam: http://www.buildingscience.com/documents/insights/bsi-046-dam-ice-dam

Gary


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## Jc the roofer (May 8, 2012)

Heat weld a smooth and a granulated. It will perform alot better than the shingles in all aspects


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