Serving Salt Lake City, UT & Nearby Areas
(385) 438-3591
Serving Salt Lake City, UT & Nearby Areas
(385) 438-3591
A membrane roof. Below a 2:12 pitch, building code and every shingle manufacturer require membrane. That's because shingles shed water instead of waterproofing. We won't touch work we're not 90% good on. Low-slope roofing is exactly where that standard matters. If your "flat" section has shingles on it, that is the problem.
Put membrane on any roof section below a 2:12 pitch, exactly as code and manufacturers require.
Shingles only shed water downhill; low slopes hold water. Membrane is what actually waterproofs a roof.
Measure the pitch of your low section before anyone quotes materials.
Utah code and every shingle manufacturer already picked your low-slope material: membrane. A bid that says otherwise is your sign to keep looking.
Mattie Tueller, Master Roofing
A low-slope roof rises less than 2 inches for every 12 inches it runs, written as 2:12. At that pitch and below, the International Residential Code and every shingle manufacturer take shingles off the table: the slope cannot shed water fast enough. So the covering has to waterproof instead.
Low slopes hide in more places than the obvious flat roof:
Measuring pitch takes a level, a tape. Two minutes: hold the level horizontal against the slope, measure 12 inches out, then measure straight down to the roof. If that drop is 2 inches or less, the section is low-slope. The material conversation changes completely.
Membrane roofing belongs on a low slope: a continuous waterproof layer with sealed seams, built to sit under standing water without letting any of it through. Shingles overlap and shed; membrane seals and waterproofs. Those are different jobs.
The membrane family covers a few different systems:
Which system fits depends on the section's size, pitch. What it ties into. That's why the answer belongs in an assessment rather than a rule of thumb. One scheduling fact works in your favor: membrane installs year-round in Utah, unlike shingles. That should never go on below 42 degrees. A failing low-slope section in January does not have to wait for spring.
Because most installers put on the material they know, and most only know shingles. Membrane is a different trade with different specs. A crew that has never welded a seam quotes what it can install, not what the roof needs.
One homeowner Master Roofing eventually helped had a roof section under a 1:12 pitch, about as flat as residential roofing gets. Five prior estimates came through, and not one mentioned membrane. Every bid proposed the wrong covering for the pitch, on a section where code and every shingle manufacturer are unambiguous.
If your low slope already has shingles and already leaks, that mechanism has its own answer: why a "flat" roof with shingles on it leaks. The short version is that the material was never designed to do what that section asks of it.
Low-slope roofing succeeds or fails on spec-level details. That's because there is no slope to forgive a shortcut. The material is only half the answer; the install is the other half.
How to tell whether an installer really knows membrane is its own question, covered in this cluster. Ask about the drip edge; the answer tells you a lot.
Low-slope sections are where I see the clearest gap between roofers who know their lane and roofers who just quote everything. A homeowner with a flat section over the porch gets five bids. Every one proposes shingles because shingles are all those companies install.
Shingles shed water, they don't waterproof: that one distinction decides everything on a low slope. Water on a 6:12 pitch is gone in seconds. Water on a 1:12 sits there, works at every seam, and finds the shortcut someone took. That is why the code and the manufacturers took the choice away.
One of my rules for Master Roofing is that we won't touch anything we're not 90% good on. I hold other roofers to the same bar. Most roofing companies are not good at flat roofing. The honest ones tell you that and step aside. One question sorts them for you: ask how they handle the drip edge, and listen for the custom bend.
Building codes, permit rules, and licensing requirements change over time, and they differ by city and county across Utah. Verify current requirements with your local building department before relying on anything here, and work with a licensed contractor who knows the rules in your jurisdiction.
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.
Shingles are allowed between 2:12 and 4:12, but only with enhanced underlayment requirements beneath them. That's because the slope sheds water slowly. Below 2:12 they are not allowed at all. If your section sits in that in-between range, the underlayment detail is what separates a roof that lasts from one that seeps.
No. Houses mix roofing materials by section all the time. Low-slope areas usually sit where they are barely visible from the street. What matters is the tie-in where the membrane meets the shingle roof: that transition flashing is a precision detail. It is where a mixed roof succeeds or fails.
Membrane is repairable when the person repairing it actually knows membrane. Most roofing companies are not good at repairing flat roofing. So failed patches are common: wrong material, wrong method. A proper diagnosis finds why the membrane failed. A proper repair uses the system's own materials and spec, not a tube of sealant.
Some slow drainage is the nature of a low slope. Membrane systems are built to tolerate water sitting longer than a pitched roof ever would. Persistent ponding that never drains is different: it usually means the drainage was never planned correctly. It deserves an assessment before it finds a seam.
Yes. Membrane systems, especially self-adhered ones, need the deck prepped to near-perfect condition. That only happens with the failed material gone. Tear-off is also when the deck gets inspected for water damage the shingles were hiding, which on a shingled low slope is more likely than not.
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.