Snow and Ice on a Metal Roof in New England: What Sliding Snow Means for Your Project

Ask anyone who has lived through a few New England winters what they like about metal roofing, and "the snow just slides off" usually comes up. Ask the same people what they do not like, and you will often hear the same sentence.

Both are true. A metal roof sheds snow quickly because the surface is smooth. That keeps weight off your structure, but it also means a lot of snow can arrive at the same moment, in the same place. It is worth planning for before you order panels, not after the first big thaw.

Shingles are rough and hold snow in place until it melts in small amounts. Metal is smooth and sheds snow in sheets, especially when the sun hits the roof or a warm day follows a cold night. Painted panels are the slickest, and steeper roofs shed faster.

For most buildings this is a benefit. Less snow sitting on the roof means less load on the framing. The question is only where that snow goes when it lets go.

Walk around the building and look at what sits below each roof edge. It takes about five minutes.

1. Let it slide and plan around it. Move the firewood stack, shift where cars park, or mark a no-walk zone in winter. This costs nothing.

2. Add snow retention. Snow retention holds snow on the roof so it melts or breaks up gradually instead of letting go in one piece. It is most useful above entries, walkways, and lower roofs.

3. Change the design. Sometimes a different roof layout or a diverter above a doorway solves the problem more cleanly than retention across the whole roof.

Here is how we handle it. We do not stock snow retention. We do have access to it, and we supply it project by project, matched to your roof. There are two broad types:

Individual snow guards. Small guards, often called "snowbirds," sit on the flat between the ribs. These are designed to sit on the flat of the panel, so they go on the flat and not on the rib.

Guardrail-style retention. This is a rail that runs across the ribs, like a guardrail. We make one type of this ourselves, in our Westfield shop, from the same material as your roofing panels, so it matches your panel color. It lays across the ribs and screws through the ribs into the framing underneath. It has a wide enough flange that it does not crush the rib. Other guardrail-style systems from other suppliers are available too.

Good catch. For regular panel screws on Tuff Rib Ag and Commercial PBR, the rule stays the same: screws go in the flat beside the rib, not through the rib, because a screw in the rib can crush it and seal poorly. We cover why in Where Does the Screw Go in a Tuff Rib Ag Panel?

Snow retention is the exception, and it depends on the type. Individual snowbirds follow the flat-plane idea. Our in-house guardrail is built differently: its wide flange spreads the load across the rib, and it fastens through the rib into the framing. Do not copy one rule onto the other. Have your contractor follow the instructions for the specific product.

Our supplier has an online calculator, and the other guardrail-style suppliers have their own. Whichever type you choose, the same four numbers drive the layout:

We make the panels and trim, and we can supply snow retention. We do not install roofing, and we do not engineer your roof structure. How much retention a roof needs, and whether your framing supports it, are decisions for your roofing contractor or an engineer, especially in heavy snow areas. Retention is loaded by a lot of snow, so it should be anchored into solid framing, not just the panel.

Ice along the eave and moisture under the roof are usually about insulation, air sealing, and ventilation, not the metal itself. Our post on whether a metal roof sweats covers the underside of the roof.

Most stock-color coil orders are ready in 24 to 48 hours. That applies to stock colors only. Custom colors typically take 7 to 10 days or longer, and trim can take up to about a week, so order trim with your panels when you can. Because snow retention is supplied project by project, mention it when you request your quote so it can be planned alongside your panels.

Send us your project details through the contact page, or email [email protected]. For snow retention, include your roof width, building length, roof pitch, and eave-to-ridge distance, along with the panel profile, color, panel lengths, and trim needs.

We deliver across New England, New York, and New Jersey, or you can pick up at our shop in Westfield, MA, which is our only location.

Request a Quote | View Our Panels