It was once generally accepted that any roof under 4 inches rise per foot was not a candidate for a shingle roof. The slope card image to the right clearly lays out roof slopes in the accepted inch per foot designations. A quick glance at this image shows the relatively low slope of a 4 inch rise per foot (or 4 in 12).
Still, the 4 in 12 slope gives a roof plenty of pitch for water to run off of the slope. For roofing shingles that rely solely upon a layered roof and slope to shed precipitation, 4 in 12 is the right limit to be placed on shingled roofs for minimum slope.
Still, the 4 in 12 slope gives a roof plenty of pitch for water to run off of the slope. For roofing shingles that rely solely upon a layered roof and slope to shed precipitation, 4 in 12 is the right limit to be placed on shingled roofs for minimum slope.
Over the past few decades, the asphalt roofing shingle industry has not only lowered the quality of some of the product offerings but the specifications for slope have also been lessened. It seems that with the onset of the sticky underlayments designated for Ice and Water, all caution has been thrown to the wind with low slope designations. The Underlayment Craze has taken hold and the selling of these underlayments has taken precedence over good and sound methods. We will highlight a problem job below where a low sloped roof (approx. 2 in 12) was installed with asphalt shingles. The result was the onset of insidious roof leaks and mold inside the home.
The damage resulting from low sloped application of roofing shingles was not only roofing related but interior walls had to be removed, mold remediation performed, new insulation installed, etc. The health issues relating to this blunder of the roofing world are still being worked out.
Word to the wise: 4 in 12 is the limit for roofing shingles!
For the unsightly visibility issue on a roof where the slope is visible, we have methods to make the roof look great! Click on the video link below for a review of a Copper Clad Rubber Roof done in Philadelphia. We also address the low sloped shingle madness in the video.
Above is a photograph of the rear of the home mentioned above. The rear porch has a slope of less than a 2 in 12 as referenced by the superimposed slope card. The troubles caused by the application of roofing shingles onto this slope is immeasurable.
The idea that somehow, a thin underlayment that has ?sticky? properties can make a shingle roof monolithic or watertight is ridiculous. The ?Ice and Water? underlayments have been sold as an end all to roofing problems. They are not an answer to anything! These underlayments are being used in place of good roofing practice and common sense! Read about our feelings on underlayments and Ice and Water underlay and The Underlayment Craze.
Swales in the decking were caused by leaking shingles installed on the low sloped porch roof.
Valleys had to be replaced because of poor installation.
Rotting, moldy decking had to be replaced after the interior mold was killed, so as to not spread the organisms.
Bad plywood replaced.
Along with the poor roofing practices listed above, a common problem in the industry today is improper nail placement. Nail guns have made novices nail faster and the results are in: Leaky Roofs!
Note: Nail Placement is almost never inspected, even by manufacturer warranty representatives.
The Low Sloped Roof recieved a heavy first ply and a heavy granular cap sheet.
Completed Low Sloped Porch Roof.
The next time you hear "Ice and Water" or "Belt and Suspenders" relating to a new roof purchase, please call us. Many new age roofers do not know what they are doing. When they look to the manufacturers for answers, the specifications offered by the "experts" lead to problems like those shown above. Trust the "Old World Craftsmen" for your roofing needs.
Let us not forget that these types of issues cause mold problems. Immediately under the rotting sheathing on this roof was a festering mold problem (images to the left and below). We also comletely gutted a bathroom in this home to rectify the mold problems from the leaks in this roof.
Under the Porch Roof was a mess and the bathroom (window in picture) had to be gutted and refinished. Remember: No roofing shingles on less than a 4:12 slope no matter what anybody says. If you hear "ice and water" underlayment, say "NO THANK YOU!"
Another example of bad methodology causing mold is linked above in the video. The industry has for the most part lost the craftsmen and now it is left with the "Underlayment Craze."Mold Remediation Philadelphia
