Todd Miller - Roofing Expert

Gutters Torn Off By Snow

A nice homeowner named Lisa emailed me the following about her recent issues with the gutters on her home being torn off by sliding snow.

I came across an old posting of yours in which you were giving advice to
a homeowner like me who had a metal roof and problems with cascading
snow ripping the gutter off. I just had the identical problem. Very
sorry to bother you, but I am in desperate need of advice and there
seems to be an endless litany of different suggestions to a problem that
appears to be very reoccurring and should have a simple solution. Your
posting sounded very knowledgeable and you offered the person additional
advice if they emailed you. So here goes…

We have a very low pitched metal roof over our kitchen (just installed
one year ago). The roofer originally installed a 5″ gutter, but I
complained that the gutter was not catching the rain enough (it was
pouring over the gutter) so he installed a 6″ commercial grade gutter.
One large snow storm and the snow avalanched off our roof and ripped
the gutter right off. Now, what should we do? My roofer suggests that
the 6″ gutter is too big and part of the problem. He wants to put back
the original 5″ gutter and install snow rails.

I just want a functioning gutter that won’t get pried off next winter
and that will work when it is raining. What size gutter and gutter
placement do you suggest? Do I need a snow rail (will it cause more
problems (we initially had ice dams which is why we paid for the metal
roof)? Do the adhesive snow brakes work and do I even need them if the
gutter is installed correctly? It is clear that we will have snow
avalanches in the future (we had them last winter when we did not have a
gutter yet).

Again, I know you may not answer me, but I would so appreciate your
thoughts. I did extensive research when we put on the seamless metal
roof in the first place. No one ever talked about gutters or snow
brakes/rails in my initial research.

Here was my response:

Thanks Lisa. I am happy to share my thoughts. Unfortunately, this side of things is more art than science.

I would not mind taking a look at an overhead view of your home, if you wish to send me the address. I’d like to get some idea of the rafter lengths and other geometry of the roof.

That said, here is my normal gutter recommendation: 6” gutters produced from minimal .032” thick aluminum, mounted as high as possible, with proper slope. They should be mounted with hidden brackets secured into every rafter tail.

Yes, the adhesive mounted snow guards can work … the adhesive requires 30 days at 60 degrees or above for proper curing. Snow fences on standing seam can allow the snow to just slide underneath.

That said, if you have had ice dams, I would shy away from using any sort of snow guard. Have your ice dams been better?

Like I said, if you wish, send me your address and I will look for satellite images and let you know my additional thoughts.