Standing Seam Metal Roof Panels in NJ, Fabricated to Length

Snap-lock or mechanical seam: which should your roofer order?

Snap-lock suits most steep house roofs. Mechanical seam, folded closed on the roof with a seaming tool, is the stronger choice for low slopes, long panel runs and roofs that hold heavy snow and ice. Our shop makes both, so the seam can follow the roof.

Snap-lock panels press together by hand along the seam. Sheffield Metals lists a 2/12 minimum for its snap-lock profiles and points to roughly 3/12 to 7/12 as their comfortable range.

It also cautions that built-up snow and ice, shifting as temperatures swing, can pull snap-lock seams apart. For snowy regions it points to mechanically seamed panels.

Mechanical seams are folded once (single-lock, about 90 degrees) or twice (double-lock, about 180 degrees). Sheffield rates its 1.5-inch mechanical profile to 2/12, or 1/12 for steel with sealant inside the seam, depending on project conditions. On porches, shed dormers and low additions, that margin matters.

Somerset, Morris and Hunterdon counties sit in New Jersey’s colder 5A energy climate zone. On long or shaded roofs there, many roofers lean toward mechanical seam even at steeper pitches. Your roofer makes the call, and we fabricate the seam on the order.

How tall should the seams be?

Most house roofs use seams about 1 to 1.5 inches tall, while 2-inch seams are common on low slopes and commercial roofs. A taller seam lifts the joint further above the water running past it.

The profile’s own slope rating governs, not the code minimum alone. We make both snap-lock and mechanical seam panels; ask us which seam heights we can run for your order.

PVDF or SMP: which paint finish lasts longer?

PVDF, often sold under the Kynar 500 resin name, holds color and resists chalking longer than SMP (silicone-modified polyester). PVDF is the usual pick for houses, and SMP suits sheds and outbuildings.

MBCI describes its Signature 300 finish as a 70 percent PVDF resin system and its Signature 200 SMP finish as its most economical option.

Read the fine print on any finish warranty. Sheffield Metals’ warranty review is a useful reality check. On PVDF, it says, chalk and fade coverage commonly lasts 10 to 30 years depending on the color, less than the film adhesion term. And a 40-year headline on SMP paint usually refers to film adhesion alone.

Finish warranties come from the coil manufacturer, and we help you get the documents for the coil on your order. Installation warranties come from your roofer. See our warranties page.

What does your roofer need to send us?

A cut list or roof plan with every panel length and count, plus the profile, metal, finish, color and trim list. We fabricate from your roofer’s measurements and never measure on site, so field dimensions are the roofer’s responsibility.

1. The job address and a contact who can answer questions.
2. Profile: snap-lock or mechanical seam, seam height and panel width.
3. Metal and gauge or thickness, finish and color.
4. For each roof plane: the panel length from eave to ridge, the number of panels at that length, and the pitch.
5. Trim and flashing: piece type, length and quantity, with a sketch for any custom bend.
6. Delivery or pickup, and any limits at the site for a long-panel delivery.

Panel length depends on the eave and ridge details your roofer plans to use. Measure for those details, not for the edge of the old shingles.

Homeowners: your roofer takes these measurements. Send their numbers with a quote request. Builders with plan sets can send plans for a quote; architectural and commercial orders get shop drawings for approval before fabrication.

Installation guidance for your roofer

We do not install, but these are the details we ask roofers to plan for on a New Jersey standing seam roof. The panel manufacturer’s installation guide governs each one.

Underlayment and ice barrier

Metal gets hot in summer sun, so roofers lay a high-temperature synthetic underlayment over the whole deck. New Jersey requires an ice barrier only in Sussex County, where January averages 25 degrees F or colder, according to DCA Bulletin 07-3. Elsewhere, an ice barrier at the eaves and valleys is standard good practice for the roofer.

Fixed and floating clips

A long steel panel grows and shrinks between a January night and a July afternoon. Fixed clips pin each panel at one point, and floating clips let the rest of it slide, so seams stay straight. Clip type and spacing follow the manufacturer’s guide, with tighter spacing near eaves, rakes and corners, where wind uplift is strongest. Under DCA Bulletin 19-1, wind and snow values come from ASCE 7 hazard tools run on the exact address.

Snow retention and ice dams

Snow slides off metal faster than off shingles, so roofers place snow guards above entries, walkways, decks and lower roofs. Clamps from makers such as S-5! grip the seam without drilling the panels. Our snow guard guide covers spacing and types.

Ice dams start inside the house. Heat escaping into the attic melts the snow up high, and the water freezes again at the cold eave, as University of Minnesota Extension explains. Air sealing and attic insulation are the real fix. See ice dams and metal roofs in New Jersey.

Permits, historic districts and solar

Re-roofing a detached one- or two-family home generally needs no construction permit in New Jersey (N.J.A.C. 5:23-2.7). Attached homes and commercial buildings generally do, so the roofer should confirm with the local construction office. Historic commissions and HOAs can add their own review; see copper and zinc roofs in historic districts. For solar, seam clamps let racking go on without drilling the panels; see solar on standing seam roofs.