Should You Shovel Your Roof? Tips for Managing Snow and Preventing Roof Failures

Hey Cora, last year we had a lot of snow, and we had a lot of roof failures.  Should I be worried about the amount of snow that is on my roof, I mean, should I shovel my roof?  Signed, Jackie Frost

Dear Jackie, that’s a “loaded” question!  Did you see what I did there – Loaded….like “snow load!”  Anyway, let’s go over this, snowflake by snowflake and give you some advice and peace of mind. 

1. Flat roofs.  If you have a flat roof you are more vulnerable to roof collapse.  This is because of the way the weight is distributed.  Older flat roofs may be what’s called a “hot roof”.  These roofs have no ventilation, they are sealed from moisture etc.  But as they get older, the roofing materials can fail due to UV rays, storm damage, neglect and moisture can infiltrate the sealed roof.  This then causes rot.  Once you have rot and a snow load…..disaster. If you have a flat roof, have it checked by a licensed contractor or engineer. 
2. Pitched roof.  This is what we are typically used to seeing in our area, sloped roofs.  But, there are different pitches.  A shallow pitch, say for instance 2/12 pitch is almost flat.  It means that every foot, there is a 2 inch difference.  That’s pretty flat.  A 4/12 pitch is pretty typical for the area.  A 8/12 pitch is pretty steep, probably cannot stand on it without a harness.  The steeper the pitch the less likely you are to have snow weight do catastrophic damage to your home.  Advice, know your pitch! If you are in an older mobile home, I would recommend shoveling your roof. 
3. Metal roofs over asphalt shingles.  Metal roofs do shed the snow better than asphalt shingles.  The shingles like to hang onto snow like grim death!  Where metal roofs allow the snow to slide off like a grilled cheese sandwich in a Teflon pan!  Because of how weight is distributed on a 4/12 pitched roof with asphalt shingles, there is usually no reason to feel like you have to shovel those roofs.  Less than 4/12, you may want to have your roof checked by a professional. 
4. Trusses over Rafters.  Trusses are an engineered roofing system that carries the weight of the roof very efficiently. Because trusses create an attic space, they can be easily ventilated, it’s unusual for trusses to rot as they are not exposed to the weather.  Rafters, on the other hand, are not engineered.  Trusses are pre manufactured and engineered, rafters are not and are not certified. I am not saying that rafters are a bad system, but they could be over-spanned, not supported well enough, not tied together correctly, they create bearing walls in the center of the home.  Trusses do not. If your raftered roof has an attic, then you can have ventilation, you do not have a hot roof and therefore, unless you have had roof leakage, you most likely do not have rotted rafters.  If however, the ends of the rafters are exposed to the weather, rot can start.  You can see it, and that rot can creep up the material with time and cause damage to that one area only, probably not catastrophic but will cause damage and probably leakage. 

Did I answer the question? Sort of, you have to know what kind of roof system you have, you need to know what pitch your roof is and what type of roofing materials were used. 

Flat roof – monitor, if the snow is wet and heavy, remove it

Shallow pitch roof, again monitor, remove if wet and heavy.

Standard pitch (4/12 and above) with trusses, you should have nothing to worry about.

Standard pitch (4/12 and above) with metal roofing or asphalt shingles, most likely, not a problem

Standard pitch with rafters, monitor, make sure you have proper ventilation at eaves and ridge.  Gable vents are okay too.

Remember the greater the pitch the less likelihood of failure.

Now, full disclosure here, I am not a roofer, just a lowly Realtor who knows a thing or two about construction and has been in new construction for decades. But if you feel you need to shovel that roof then do so.  I would recommend you hire a professional, don’t try and do it yourself.

Winter of 2025 is upon us – enjoy the winter sports and snowmachines and if you need a new house with a bigger garage – you know who to call!  I will answer the phone!