Serving Salt Lake City, UT & Nearby Areas
(385) 438-3591
Serving Salt Lake City, UT & Nearby Areas
(385) 438-3591
A system sized by eye is not a lighter version of the right one. It is a different product that happens to look identical from the driveway.
Snow retention looks like small hardware. A row of brackets, bolted or clamped on, and the job appears finished. What those brackets are actually doing is holding tons of snow in place on a slick surface for months at a time. Whether that works comes down to a calculation, and you can ask to see it.
· About an 11 minute read
Held snow is tons of force doing slow motion math on every bracket. In a Utah winter, force does not care how sturdy the hardware looked in a catalog.
Mattie Tueller, Master Roofing
Metal roofs shed snow because there is nothing on the surface for it to grip. When a slope lets go, it goes all at once as a slab.
Snow retention's job is to stop that. Not to slow it down, and not to break it up. To hold it in place, through the whole winter, until it melts off gradually instead of arriving somewhere in one piece.
That is a structural job, and the weight involved surprises people.
Most roofing choices are about durability. If you get one wrong, the roof lasts fewer years than it should. That is expensive and it is not dangerous.
This one is different. Sliding snow has dented cars, broken windows, and killed someone in this state. That death is why Park City now requires snow retention on commercial buildings.
An honest opinion, stated plainly: snow retention should be building code for metal roofs. It is strange that it is not. It stays optional because it adds cost to a bid, most winters pass without incident, and a homeowner comparing quotes has no way to know which line item is the one that matters.
So this guide is about the difference between a system that was designed and one that was estimated. From the driveway, they look the same.
A real layout comes from a calculation, and the calculation takes four inputs. Every one of them is specific to your house.
Change any one of those and the answer changes. That is the whole reason a rule of thumb cannot work here.
This is not proprietary knowledge. Manufacturers of engineered snow retention systems publish layout calculations for their products. The snow load figure comes from published data for your address.
So a company doing this properly is not inventing anything. They are running numbers that already exist, for a house that has a specific pitch and a specific location.
Which makes the request simple. Ask for the ground snow load figure used and the layout on paper. It is a short conversation with a company that did the work, and a very awkward one with a company that did not.
Mountain homes carry far higher snow loads, so the systems up there are doing more work. But damaging slides happen on low-elevation Wasatch Front homes too.
The deciding factor is not how high you live. It is the combination of a slick surface, a pitch, and something underneath the eave that matters.
Here is the part that makes this worth reading before you buy rather than after.
When snow retention is undersized, the snow does not simply push past it. The brackets hold, for a while. Held snow is tons of force doing slow motion math on every one of them.
Force does not care how sturdy the hardware looked in the catalog. Eventually something gives, and what gives is whatever is weakest in the chain.
You bought safety equipment and it turned into a demolition tool. That is a fair thing to be angry about, and it is worth naming plainly: the snow did not do that. The guessing did.
To be fair about it, snow guards look simple. They are small components. They bolt or clamp on. A crew that has installed them before can put them up without ever seeing a calculation.
And nothing about the finished job looks different from a designed one. Same hardware, same rows, same appearance from the ground. The difference is invisible right up until the winter it matters.
This is the counterintuitive one, and it is the most common shortcut.
A homeowner points at the front door and asks for guards above it. Reasonable request. But snow retention placed only above one area concentrates the load it catches into that area, rather than distributing it across the plane.
So the section you protected is now carrying force that the rest of the roof was supposed to share. Coverage is designed across the whole roof plane for that reason, not just above the spots you were worried about.
Two systems with identical bracket counts can have completely different holding capacity. The difference is how they grip the roof.
Each method has published engineering limits. A clamp rated for a specific seam profile does not perform the same on a different one. An anchor's capacity depends on what it is fastened into.
The question to ask is narrow and useful. How is this system attached to my roof, and what is that attachment method rated to hold? A company that designed the job answers with a number. One that did not will describe the hardware instead.
Attachment options are decided by what your roof actually is. Exposed fastener panels, standing seam, and stone-coated steel all present different surfaces to grab.
So the sequence matters. The roof material is chosen first, and the retention system is designed for that material. Retrofitting a system onto a panel it was not made for is where a lot of the trouble starts.
Anything fastened through a metal roof is a hole in a waterproof surface. Done correctly with the right sealing detail, that is routine and reliable. Done casually, it becomes a leak in year three that nobody connects back to the snow guards.
Worth asking whether the attachment method affects your roof's warranty, particularly if the roof and the retention system came from different companies.
This is the practical test, and it works without any technical knowledge on your part. You are checking whether a design exists.
A quote that names no snow load figure and shows no layout is an estimate of price, not a design. That is the single clearest line between the two kinds of company, and you can see it on the paper in front of you.
You are not evaluating the engineering. You are listening for whether numbers arrive when you ask for them.
A company that ran the calculation will tell you your snow load figure quickly, because they looked it up to do the job. A company that guessed will talk about the hardware, the brand, or how many they have installed on houses like yours.
Ask what happens if the system is not enough. A designed system has a calculated margin. A guessed one has an opinion.
And ask whether the roof itself needs anything first. Retention adds load to the roof structure at specific points. So it is worth knowing the deck and fastening underneath are sound first.
If two quotes disagree wildly on how much hardware your roof needs, ask each one for their snow load figure and their layout. Very often the gap is not a disagreement about engineering. It is that one of them did the math.
If your system tore up part of your roof last winter, there is something genuinely useful hiding in that bad outcome.
You now know exactly what force won. That is information nobody had before, and the rebuild gets designed against a real number instead of an assumption.
Do not simply add more of the same hardware. If the layout was wrong, adding brackets to the same wrong pattern can concentrate load further. The redesign starts from the calculation, not from the row that failed.
Most systems that fail this way were installed by people who were not trying to shortchange anyone. They installed snow guards the way they had seen snow guards installed. Nobody handed them a calculation, and nothing in the finished job looked wrong.
That is not an excuse, and it does not help your roof. It is worth knowing because it changes what you ask the next company. The question is not whether they are honest. It is whether they ran the numbers.
Nothing. Snow sits on the roof all winter and melts off gradually. Nobody thinks about it. Snow retention done right is boring, and boring is the entire goal.
Before any of the engineering matters, there is a ten minute job only you can do. It decides whether this is a safety project or a nice-to-have.
Go outside and stand under each eave of your house. Look up at the roof above you, then look down at what is beneath your feet.
If the answer under every eave is bare lawn, you have your answer and it cost you nothing. If the answer is your front door, you also have your answer. This is not really a mountain question. It is a question about what is standing underneath your eaves when the roof lets go.
Some of the risk is seasonal and only becomes obvious once there is snow up there. Where does the snow actually build? Which slopes hold it longest? Where has it already come off, and what was in the way?
Photograph what you see. That record is genuinely useful to whoever designs the system. It shows how snow behaves on your roof rather than how it behaves in general.
Your list does not replace the calculation, and it should not become the layout. Coverage still gets designed across the whole plane. But it tells the designer where failure would hurt most, and it tells you why you are spending the money.
Work these in order. The first two cost nothing and they settle whether the rest applies to you.
Metal and other smooth panels almost always do. Asphalt shingles almost always do not, because the granulated surface holds snow in place. Low-slope membrane toward the steeper end of its range can shed too.
Doors, walkways, driveways, decks, gas meters, property lines. Ten minutes. If nothing is under any eave, you can stop here with a clear conscience.
Call your city or county building department, or look it up in the published hazard data. Having this number before you take quotes changes every conversation that follows.
What snow load did you use, and can I see the layout on paper? Then check that coverage is across the whole roof plane rather than only above the areas you pointed at.
Clamps, anchors, and adhesive components all have published limits, and those limits depend on your panel profile. A designed job answers with a number rather than a brand.
One more thing if you are choosing a metal roof right now. Raise snow retention while you are still comparing roofing bids, not after the panels are on. Designing the two together is cheaper and gives you more attachment options than retrofitting later.
Then let it be boring. That is what you are paying for.
When I assess a roof that its own snow retention tore up, I say the quiet part first. The snow did not do that. The guessing did.
You bought safety equipment and it turned into a demolition tool. You have every right to be angry about that.
Here is the fair part, and it matters for what you do next. Guessing is common because snow guards look simple. They are small components that bolt or clamp on. A crew that has installed them before can put them up without ever seeing a calculation. And nothing about the finished job looks different from a designed one. Same hardware, same rows, same view from the driveway. The difference stays invisible until the winter that matters.
My honest opinion is that snow retention should be building code for metal roofs, and it is strange to me that it is not. Park City requires it on commercial buildings now, and that requirement exists because a woman was killed by snow coming off a four-story hotel.
So Master Roofing engineers these to the snow load data for the address and designs them across the whole roof, or does not install them. Held snow is tons of force, and force does not care how sturdy the hardware looked in the catalog.
The check that protects you is short. Ask for the snow load figure and the layout on paper. That is an easy conversation with a company that did the work, and a very awkward one with a company that did not.
Snow retention is the rare roofing decision where the stakes are safety rather than durability. Sliding snow has done real damage and worse in this state, and the physics do not care what kind of building it comes off.
What separates a system that works from one that becomes its own hazard is a calculation. Ground snow load, roof pitch, panel profile, and how far the snow travels. Four inputs, all specific to your house, and none of them guessable from the driveway.
You do not have to understand the engineering to insist on it. Ask what snow load figure was used. Ask to see the layout. Check that the coverage runs across the whole roof plane rather than just above the front door.
Then it should disappear from your life entirely, which is exactly what you paid for.
Snow retention done right is boring. Boring is the whole idea.
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.
Enough to hold your roof's real snow load, calculated rather than estimated. The inputs are your ground snow load, the roof pitch, the panel profile, and how far the snow travels to reach the eave. Change any one and the answer changes, which is why a rule of thumb cannot work. Manufacturers of engineered systems publish layout calculations, so the numbers exist and can be requested. Ask any bidder for the snow load figure they used and the layout on paper. A quote that shows neither is a price estimate rather than a design.
That is the most common shortcut and it can make things worse. Snow retention placed only above one area concentrates the load it catches into that area instead of distributing it across the roof plane. So the section you protected ends up carrying force the rest of the roof was supposed to share. Coverage is designed across the whole plane for that reason. Bring your list of what sits under each eave to the conversation, because it tells the designer where failure would hurt most. Just do not let that list become the layout.
Almost certainly because the system was guessed rather than engineered. When retention is undersized, the brackets hold for a while, and held snow is tons of force working on every one of them. Eventually the weakest part gives. Fasteners tear out, or the slab becomes the lever that peels metal off the deck. Partial coverage makes this more likely, because it concentrates load. The useful part is that a failure shows exactly what force won. So the replacement gets engineered against a real number instead of an assumption.
Properly designed, no. Clamp systems grip the raised seam of a standing seam roof without penetrating it, so nothing goes through the waterproofing at all. Fastened anchors do penetrate, and then the sealing detail at each hole becomes part of whether your roof leaks. Done correctly that is routine and reliable. Done casually it becomes a leak in year three that nobody connects back to the snow guards. Ask which method is being used, what it is rated to hold, and whether it affects your roof warranty.
No, and that assumption is why some valley homeowners get caught. Mountain homes carry far higher snow loads, so systems up there work harder. But damaging slides happen on low-elevation Wasatch Front homes too. The deciding factors are a slick roof surface, a pitch, and something underneath the eave that matters. A section of roof only four feet wide has done real damage in a single slide. It dented car hoods and broke windows in a Utah driveway. Elevation changes the size of the system, not whether you need one.
Usually not. The granulated surface of an asphalt shingle is rough enough to hold snow in place. So it melts off gradually rather than releasing in a slab. That is one of the quiet advantages of shingles in a snowy climate. The roofs to think about are metal and other smooth panel systems, plus low-slope membrane toward the steeper end of its range, which can shed. If you are switching from shingles to metal, this is a new consideration that did not apply to your old roof.
While you are still comparing roofing bids, not after the panels are on. Designing the roof and the retention system together is cheaper than retrofitting later. It also gives more attachment options, because the panel profile decides what a bracket can grip. It also means the load path is considered from the start, since retention concentrates force at specific points on the structure. If a metal roofing quote does not mention snow retention at all and you have anything under your eaves, that is worth raising directly.
Ask each company for two things: the ground snow load figure they used, and the layout on paper. Very often a wild gap between quotes is not a disagreement about engineering. It is that one company ran the calculation and the other did not. You do not need to evaluate the math yourself. You are checking whether numbers arrive when you ask for them. A company that designed the job answers quickly, because they looked the figures up in order to do it.
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.