Standing seam mechanical lock metal roof panel profile

Mechanical Lock Standing Seam Panels

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Snap lock metal roof panel profile

Snap Lock Standing Seam Roof Panels

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Nail Strip Standing Seam Snap Lock

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U seam metal roof panel profile

U Standing Seam Roof Panels

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Flat lock metal roof and wall panel profile

Flat Lock Roof & Wall Panels

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Metal Roof Panel Machine

K&M knows metal roofing. We offer four traditional panel systems: Mechanical Lock (Single / Double Lock), Snap Lock, Nail Strip, and U-Panels. Each System has an available stiffening rib option to strengthen the panel and help prevent oil canning. We offer our panels in a variety of widths up to 27” and infinite lengths, or usually up to 40' for transportation purposes. K&M Sheet Metal also offers curved panels, tapered or straight panels, as well as all the accessories needed for installation, such as clips, flashing metal, roofing nails and metal roofing tools. UL & ASTM certifications are available upon request.
Please do not hesitate to contact us, we are happy to help you find the right system for your needs. Click Here to Request a Quote.
For metal roof installation jobs, please contact Century Slate Roofing.

  • Custom made to order per your specifications
  • Copper, Aluminum, Steel, Zinc, Lcc, Freedom Gray, etc
  • Flashing metal available

What is the cost of a metal roof?

Metal roofs panels are made to order and need to be quoted. Please, contact us for an estimate.

Metal Roof Panels and Wall Panels

Mechanical Lock Standing Seam Panels

Double lock standing seam copper roof panels and gutters

The most widely used, traditional metal roof system, the mechanical lock, also commonly referred to as just standing seam roof, can be installed as a single lock or double lock system.
This profile panel is available in 1” or 1.5” high standing seam. The double lock has long been considered the best locking system available and is it not uncommon to find century old systems still functioning properly. Commonly used materials are copper, lead coated copper, freedom gray, zinc, and Kynar coated steel and aluminum.
Copper based systems offer the advantage of being able to be soldered where needed, where aluminum systems are easier to work with and more malleable, while Kynar steel systems are a more tough panel, although not recommended for installations near the ocean.
These panels are secured to the roof deck via roof clips and can be curved.

Snap Lock Standing Seam Roof Panels

Mechanical double lock standing seam colonial red aluminum roof panel installation

The Snap Lock seam is offered in 1” and 1.5” high seams. This system snaps together as the panels are installed. Snap Lock eliminates the need to mechanically lock the seams together, allowing for a much faster installation, much easier for those looking for a DIY project. Snap Lock also incorporates fixed or expansion cleats that allow the panel to expand and contract. Snap lock panels cannot be curved.
Because this system relies on the rigidity of the material used, softer materials such as copper are not recommended.

Nail Strip Standing Seam Roof Panels

Red mechanical lock steel roof panels installation

The Nail Strip Lock system is offered in 1” and 1.5” high seams. This system snaps together just like a Snap Lock system and has a hidden built –in nail strip that eliminates the need for cleats. This is an economical system, very quick to install, ideal for short runs where expansion and contraction are not a concern.
As the snap lock system, this system relies on the rigidity of the material used, therefore softer materials such as copper are not recommended.

Standing U Seam Metal Roof Panels

The U-Panel is offered in 1” or 1.5” seam heights. U-Panels can be used in conjunction with heavy-duty batten cleats to form Batten Lock Panels.
Batten Cleats are installed between each panel. A batten cap is then snapped into place over the cleat. This eliminates the need for installing wood battens.

Flat Locked Roof and Wall Panels

Flat locked and standing seam copper panels

Flat-Lock roofing panels come in a variety of shapes, sizes and metals. These panels are ideal for flat roofs, domes, turrets and any wall panel system – interior or exterior. Metal clips and nails for fastening the panels are available. Pre-Tinning of edges is also available.
Flat lock panels always need to be soldered on flat roofs. The the exception lies with vertical applications (walls). That means colored materials like Kynar aluminum and steel can only be use on walls.
Normally, to keep costs down, flat locked panels are made with dimensions that get an even number of panels out of a sheet or coil.
For example, if using copper sheets 3'x10', it is common to cut panels with 18" x 24", where 10 panels are extracted from every sheet.
The lock size varies, but it is commonly 0.5"-0.75".
Flat locked panels are commonly used with zinc for wall applications, with more of a diamond shape.

Profile Minimum Slope / Pitch Material Loss
1" Standing Seam 3":12" 3"
1.5" Standing Seam 1.5":12" 4"
1" Snap Seam 3":12" 3"
1.5" Snap Seam 1.5":12" 4"
1" Nail Strip Snap 3":12" 3"
1.5" Nail Strip Snap 1.5":12" 5"
1" U Panel 3":12" 2"
1.5" U Panel 1.5":12" 3"
Flat Lock Panel 0":12" for soldered panels Custom. Usually ~1.5"

Coil Sizes

The ideal coil sizes are the ones sold as standard by the mill. These are normally slit from a 48" master coil, but sometimes 60".

Copper: 24", 20" and 18" wide. 15" and 12" can also be used since they are sold as standard for gutters. 16oz and 20oz.

Freedom Gray: 24", 20" and 18" wide. 16oz and 20oz.

Galvalume Plus, Kynar Steel (Galvanized) and Kynar Aluminum: 24", 20", 18" and 16" wide. 0.032", 0.040", 24 and 22 gauge.

Lead Coated Copper: 24", 20" and 18" wide. 16oz and 20oz.

Zinc: 0.7mm and 0.8mm 19.7" wide.

The pictures below are courtesy of The Century Slate Roofing Company.

FAQs - Frequently Asked Questions

What is the best standing seam roofing system?

The most widely used system that can be seen still working on some applications for over a century is the standard mechanical lock standing seam roof panel.

Why choose standing seam metal roofing over corrugated roofing panels?

The single main reason why you would choose a standing seam roof system is because it is a better system, and the main reason for this is because when properly installed, no fasteners are visible, nothing pierces through the panels to attach it to the roof deck. This is all done under the panel, which minimizes the chances for leaks. Corrugated roof systems are installed by fastening through the panel into the roof deck, meaning the panel is now pierced.

What is the difference between a single lock and a double lock roof panel?

They are both the same panel, known as simply a standing seam panel, or a mechanical lock panel. One side of the panel has the male lock while the other has the female lock. To put these panels together, the female lock is placed over the male portion of the panel. When the first portion of the female lock is folded, that creates a single lock, which is a horizontal lock. If the second portion of the female lock is also bent, that creates a double lock, which is a less visible, vertical lock.
Double lock is the choice of most because of its longevity and looks.

What is the easiest roof panel to install?

Out of the standing seam roof panels we offer, the snap locks are the easiest. No need to manually fold the seams, just snap them together.

What else is needed for installing a metal roof?

You will need all the flashing metal to go with it, which may be: drip edge, j channel, z channel, ridge cap, valley flashing, head wall flashing. you may also need starter panels, custom flashing material. You will need the right tools, and depending on the material, a soldering iron and soldering supplies.

What is the best material for a metal roof?

This heavily depends on what you want for looks and your application.
  • Copper is widely used. It is a soft, malleable material that is easy to work. It can also be soldered, which is great for awkward flashing conditions / locations. This allows for a more leak proof system. Material such as zinc, lead coated copper and freedom gray share the same capabilities.
  • Aluminum is a soft material, easy to work with. It is available in colors and it is cheaper than copper for example. It also does not rust.
  • Galvanized steel kynar coated or Galvalume steel kynar coated are a more rigid material, not as easy to work with, but more rugged, capable fighting the elements a little better in some situations. This system eventually rusts, however, it should not before its expected lifetime, unless installed in environments not recommended, such as near the ocean.

K&M Sheet Metal supplies metal roofing panels to Contractors and Home Owners in the local North Carolina Market (Raleigh, Charlotte,  Durham), along with  the neighboring states of South Carolina, Tennessee and Virginia as well as nationwide shipping for some orders when possible due to the size of the panels.

0.032" / 0.040" Kynar Aluminum and 24 gauge / 22 gauge Galvanized Steel Metal Roofing Common Color Options
Black kynar aluminum and galvanized steel

Matte black

Dark bronze aluminum and galvanized steel

Dark bronze

Medium bronze aluminum and galvanized steel

Medium bronze

Stone white aluminum and galvanized steel

Stone white

Bone white aluminum and galvanized steel

Bone white

Slate gray aluminum and galvanized steel

Slate gray

Charcoal aluminum and galvanized steel


Forest green aluminum and galvanized steel

Forest green

Hartfort green aluminum and galvanized steel

Hartfort green

Most popular metal roofing colors in Galvanized Steel and Aluminum Kynar are Dark Bronze and Slate Gray
Click here for a full list of Kynar metal colors

Other Material Options for Metal Roofing


Freedom gray

Freedom gray

Lead coated copper

Lead coated copper





Copper is the most popular metal for metal roofing. It is offered in 16 oz and 20 oz.
Freedom Gray (zinc / tin coated copper) is offered in 16 oz and 20 oz.
Galvalume Plus is offered in 24 and 22 gauge.
Lead Coated Copper is offered in 16 oz and 20 oz.
Zinc is offered in 0.7 mm and 0.8 mm.

Other colors, materials and thickness may be available upon request.
Please click here for a full selection of colors and materials offered.