Metal roofing glossary

Galvalume

The silver, unpainted coating on our steel panels (zinc and aluminum over steel). It is a finish, not a color. It is the lowest-cost option and lasts for decades in normal weather, but it is not recommended over animal confinement, and its warranty is usually limited near salt water.

SMP (silicone-modified polyester)

A standard painted finish. Good color choice at a moderate price.

Kynar 500 (PVDF)

A premium paint finish that resists fading and chalking the longest. Costs more than SMP.

Gauge

Steel thickness. A smaller number is thicker: 24 gauge is thicker and stiffer than 26, and 26 is thicker than 29. See the gauge guide.

Purlin

The horizontal beams or boards that panels are screwed to. R Panel and PBR can go directly on purlins. Over solid decking you also use underlayment.

Pitch

How steep the roof is, written like 4/12: the roof rises 4 inches for every 12 inches of horizontal run. Steeper roofs have more surface area.

Square

A roofing measurement: 100 square feet of roof. Screws are counted per square.

Coverage width

How wide one panel covers once it overlaps its neighbor. R Panel, PBR and Tuff Rib cover 3 ft each. This is different from the full width of the sheet.

LF (linear foot)

One foot of panel length. We price panels per LF. A 12-ft panel is 12 LF.

Exposed fastener panel

Screws go through the face of the panel with a rubber washer. Lower cost and simple to install. PBR, R Panel, Tuff Rib, 5V Crimp and corrugated are exposed fastener.

Standing seam

Panels lock together at raised seams and the fasteners are hidden. Higher cost, cleaner look, longer lasting.

Clips vs nail strip

Two ways to hold standing seam in place. Clips are small brackets that hide under the seam and let the panel move with heat. A nail strip is a flange along the panel edge that is screwed straight to the deck, so the panel is fixed at that edge.

9-5 / Tuff Rib

The same panel. A lightweight 3 ft coverage exposed fastener panel with small ribs 9 inches apart. Our lowest-cost exposed fastener panel.

PBR

Purlin Bearing Rib. A 3 ft coverage exposed fastener panel with tall ribs every 12 inches. Strong, popular on barns and metal buildings.

R Panel

A 3 ft coverage exposed fastener ribbed panel with ribs 12 inches apart, similar to PBR. It goes over purlins or over a solid deck, depending on the building and the panel's approval. See R Panel vs PBR.

5V Crimp

Old-Florida style panel with V-shaped crimps every 12 inches. Exposed fastener.

Eave

The bottom edge of the roof where water runs off. Eave trim (drip edge) finishes it.

Rake

The sloped edge of a gable roof. Rake or gable trim covers it.

Ridge

The top peak where two slopes meet. A ridge cap covers it.

Valley

The low line where two roof slopes meet. Valley trim channels water away.

Closure strips

Foam strips that fill the gap between the panel ribs and the ridge or eave trim, keeping out wind-driven rain, debris and bugs. They are set in tape sealant top and bottom.

Butyl tape

A sticky sealing tape used in panel side laps, under ridge caps and on trim laps.

Underlayment

A protective layer under the metal, over a solid roof deck. Panels screwed to open purlins usually have none.

Trim

Bent metal pieces that finish the edges and joints of a roof: ridge cap, eave (drip edge), rake (gable) trim, corners and J-channel. Trim is priced per 10-ft piece, see the trim price list.

Flashing

Trim that seals where the roof meets something else, like a wall, a chimney or a pipe, so water cannot get behind the metal.

Rib

The raised part of a panel that gives it strength and sheds water. The flat part between ribs is the pan.

Corrugated

The classic wavy, rounded panel. Exposed fastener, 2 ft coverage, light-duty look.

Gable

The triangular wall at the end of a pitched roof. The sloped roof edge above it is the rake.

Deck

The solid surface under the roof, usually plywood or boards. Panels go over it with underlayment in between. Open framing with purlins (no deck) is common on barns and sheds.

Custom trim bent to your drawing is $63.00 per 10-ft piece, the same price for everyone.