Serving Salt Lake City, UT & Nearby Areas
(385) 438-3591
Serving Salt Lake City, UT & Nearby Areas
(385) 438-3591
Because shingles were never designed to waterproof, only to shed. On a slope too shallow to shed, water sits, creeps under the overlaps. Finds the nail holes. Below a 2:12 pitch, code and every shingle manufacturer require membrane instead. I tell homeowners: roofs don't leak because materials are bad. Yours leaks because the wrong material is on the spot.
Stop patching the shingles and replace that low-slope section with membrane, the covering code requires.
Shingles shed water downhill; standing water on a shallow slope works under every overlap and nail.
Measure the section's pitch: 2 inches of rise per foot is the line.
That flat section over your Utah porch was never a shingle job. Change the material and the leak stops being a mystery.
Mattie Tueller, Master Roofing
Because a shingle roof is a shedding system, not a sealed one. Shingles overlap like scales. The design depends on gravity moving water downhill fast enough that it never gets a chance to travel sideways or backward under the laps.
Take away the slope and you take away the mechanism. Water lingers, wind pushes it uphill under the overlaps. Every nail hole becomes a candidate entry point. That's because nothing about a shingle seals around standing water.
That is why the International Residential Code and every shingle manufacturer draw the same line: below a 2:12 pitch, shingles are not an approved covering at all. The rule is not bureaucratic caution. It is the manufacturer telling you their own product cannot do this job, in writing, in the installation spec.
Slowly, then reliably. A shingled low slope usually starts leaking in exactly the conditions that give water time to work.
Early on it leaks only in the long storms. That's why the problem gets misread as a small fixable detail. The detail is the whole covering.
Almost always because shingles were what the installer knew. Membrane is a different discipline with different specs. A crew that has never installed it will roof every section, whatever the pitch, in the material they carry.
The usual paths to a shingled low slope:
It is common enough that homeowners collect multiple bids without membrane ever being mentioned. What actually belongs on a low-slope section covers the fix side in full, including the story of a roof under a 1:12 pitch where five estimates in a row proposed the wrong covering.
The real fix is replacing the covering on that section with membrane: a continuous waterproof layer built to sit under water without passing it. Patching the shingles buys weeks; changing the material ends the problem.
One caution from the National Roofing Contractors Association's low-slope guidance: membrane systems have their own installation specs. The details, especially the edges, decide everything. Getting the right material installed the right way is the entire fix.
By the time homeowners ask Master Roofing this question, most have paid for the same leak twice. Someone patched it, it held through the short storms. The first long soak or spring snowmelt brought the stain back. They start wondering if the roof is cursed or the roofers are crooks.
Usually it is neither. Below a 2:12 pitch, shingles are the wrong answer no matter how well they were installed. The crew that put them there probably was not dishonest. They just only knew shingles. They roofed what was in front of them with what was on the truck. The patch crews after them treated symptoms of a mismatch nobody named.
Roofs leak for findable reasons. On a shingled low slope, the reason is found before I ever climb the ladder: the material and the pitch disagree. The pitch always wins. Fix the material and the mystery retires for good.
This article is general information about Utah roofs, not an assessment of yours. Every roof is different, and no article can tell you what is actually happening on your specific house. Have a licensed roofing contractor look at it in person before you act on anything here.
Hold a level horizontal against the slope, measure 12 inches out along it, then measure straight down from the level's end to the roof surface. That drop is your pitch: 2 inches or less means the section is below 2:12 and shingles are not an approved covering there. Two minutes with a tape settles the whole diagnosis.
No. A second layer of the wrong material is more of the wrong material: the slope still cannot shed, the water still dwells. Now leaks are harder to trace through two layers. Layovers also bake from underneath and complicate insurance. On a low slope the covering type is the problem. So adding covering cannot be the fix.
Dwell time. A short rain drains off before the water works under the laps. So the roof appears fine. Long soaking storms give water hours to creep. Snowmelt is the extreme case: snow melts from underneath and keeps the section wet for days. The leak schedule follows the water's schedule. That's the signature of a shedding material asked to waterproof.
Temporarily at best. Sealants and coatings over shingles fail the same way patches do: the shingle system underneath still cannot handle standing water. Most consumer sealants are not made to survive sun, freeze, and thaw year after year. Coatings have real uses on actual membrane roofs. Over shingles on a low slope, they are a countdown.
Usually just the low-slope section. The steep parts of the roof are doing a job shingles are good at. They can stay on their own schedule. The section gets membrane, tied into the surrounding shingles with transition flashing. That is the one precision detail to insist on. Scoping it as a section keeps the fix proportional to the problem.
We're here to see what's going on with your roof. A real assessment starts with your history and your attic, not a number from the driveway. You'll get a straight answer about what's up there, what it needs, and what it costs. Sometimes the honest answer is: your roof looks great.