Roof Trim · Metal building trim guide
Metal Roof Eave Trim and Drip Edge for R-Panel and PBR
Eave trim, or drip edge, finishes the low edge of a metal roof where water runs off and covers the eave framing.
Also called: drip edge, eave drip, simple eave, sculptured eave, eave flashing
Metal roof eave trim finishes the low edge of the roof, where water runs off the panels. Most people call it a drip edge. It covers the face of the eave framing and kicks water out and away so it does not run back down the wall or soak the framing.
This page explains where eave trim goes, how the 4 inch and 8 inch sizes work, how to figure how many pieces you need with a real example, and how to install it. It applies to carports, barns, sheds and shops built with R-panel or PBR roofing in the Houston area.
What Is Metal Roof Eave Trim?
Eave trim is a bent piece of sheet metal that wraps the low edge of the roof. On metal buildings it usually has a top flange that goes under the roof panel, a face that covers the eave strut or purlin, and a small kick at the bottom that acts as the drip edge.
It keeps water from wicking back under the panel and running down the framing. It covers raw framing so it looks finished. And with inside closures above it, it helps block wind, birds and bugs at the eave.
Where Eave Trim Goes on a Metal Building
Eave trim runs along the long, low edges of the roof. A gable building has two eaves, one on each side. A single-slope lean-to or carport has one low eave; the high edge gets high-side eave trim instead.
If you are putting on gutters, the gutter often takes the place of eave trim or hangs along with it, depending on the building. On open carports, crews sometimes leave the eave plain, but trim makes the edge cleaner and stronger.
Metal Roof Eave Trim Sizes, Gauge and Colors
Eave trim is typically 26 gauge to match R-panel and PBR, in Galvalume or painted colors. It most often comes in a 4 inch or 8 inch face. The right one depends on how deep your eave strut, purlin or header is: a 4 in. member gets 4 in. trim, an 8 in. member gets 8 in. trim. Measure the face before you order. Picking the wrong size is one of the most common reasons trim gets reordered.
Simple eave and sculptured eave shapes are both common. Pieces are typically 10 ft long; ask us. Custom eave trim can be bent to fit odd framing or to match an older building.
How to Measure Eave Trim and How Many Pieces to Order
Formula: eave length (building length plus any gable overhang) x number of eaves (2 for gable, 1 for single slope) x 1.10, then divide by piece length and round UP.
Worked example: a 30 x 40 gable building with 12 ft walls and a 3:12 pitch. Each eave is 40 ft, two eaves = 80 ft. 80 x 1.10 = 88 ft, so order 9 pieces of 10 ft eave trim. Check the runs: each 40 ft side takes four full pieces plus a short piece about 1 ft long after laps. The leftover from the ninth piece covers the short piece on the other side, so 9 works.
Add the inside closures that go with it: 40 ft / 3 ft panel coverage = 14 closures per eave, 28 for the building, plus a few spares.
How to Install Metal Roof Eave Trim
On new metal buildings, eave trim usually goes on before the roof panels so the panels lap over it. Order of work varies by building and panel maker, so follow your building drawings if you have them.
- Snap a line so the trim runs straight along the eave strut or purlin.
- Start at the end away from the prevailing wind. Set the top flange on the eave member and fasten it with #12 or #14 self-drilling screws about every 12 to 24 inches.
- Lap each next piece about 2 to 4 inches over the last, with sealant in the lap, so laps face away from the wind.
- Run butyl tape across the top flange, set the inside foam closures on the tape so they line up with the panel ribs, then add a second strip of tape on top.
- Set the roof panels so they overhang the trim slightly, then fasten through panel, closure and trim into the eave member with roofing screws in the flats next to each rib.
- If you are adding eave trim to an existing roof, slide the top flange up under the panel ends and fasten it to the face of the eave member instead.
Common Eave Trim Mistakes to Avoid
- Ordering 4 in. trim when the eave member is 8 in. (or the other way around).
- Leaving out the inside closures, which lets wind and wasps into the panel ribs.
- Letting the panel stop short of the drip edge so water runs back under it.
- Fastening trim with no lap or no sealant in the joints.
- Not counting the gable overhang in the eave length.
- Forgetting that a gable building has two eaves.
What to Order With Eave Trim
Eave trim works with the closures and trims around it. Order these together:
- Inside foam closures matched to your R-panel or PBR profile.
- Butyl tape for above and below the closures.
- Color-matched roofing screws and #14 lap screws.
- Rake trim, ridge cap, or high-side eave trim for the other roof edges.
- Gutter and downspouts if you want to control runoff.
Get Metal Roof Eave Trim in Houston From Ironrod Steel
Ironrod Steel Co. rolls R-panel and PBR roofing and supplies matching eave trim in 4 in. and 8 in. sizes, along with closures, screws and butyl tape. Send us your building size and a photo of the eave framing and we will help you pick the right size and count. Pick up at 8122 Hillsboro St in Houston or ask about delivery across Houston and Southeast Texas. Call or text (281) 902-7619.
Eave Trim (Drip Edge) FAQ
Is eave trim the same as drip edge?
Mostly, yes. On metal buildings, eave trim covers the eave framing and has a drip edge built in at the bottom. On houses, drip edge is usually a smaller flashing under the roof edge, but people use both names for the same job.
How do I know if I need 4 inch or 8 inch eave trim?
Measure the face of the eave strut, purlin or header the trim will cover. A 4 in. member takes 4 in. trim and an 8 in. member takes 8 in. trim. If you are not sure, send us a photo with a tape measure on it.
Does eave trim go on before or after the metal roof panels?
On new construction it usually goes on first so the panels lap over the top flange. On an existing roof it can be slid under the panel ends and fastened to the eave face. Follow your panel maker's details when you have them.
Do I need closures at the eave of a metal roof?
On an enclosed building, yes. Inside foam closures go under the panel at the eave to fill the rib gaps. Some open carports skip them, but closures keep out wind-driven rain, birds and wasps.