Rolling Steel Door Curtain Replacement
Replacing damaged curtain slats on a rolling steel (coiling) overhead door, including partial slat replacement and full curtain replacement. Covers damage assessment and slat ordering, operator lockout/tagout, barrel restraint, removal of the bottom bar and damaged slats, inspection of adjacent slats and guides, installation of replacement slats, curtain travel testing, fire-rated governor and drop-test verification, and operator reconnection with final safety-device testing.
Warnings
This procedure must only be performed by trained, qualified commercial door technicians experienced with rolling steel door systems. Rolling steel doors are extremely heavy and contain high-tension counterbalance springs that can cause severe injury or death.
The counterbalance springs inside the barrel are under extreme tension. Do not disassemble the barrel or attempt to access the springs without manufacturer-specific tools and training.
When working with the curtain partially removed, the door weight distribution changes. The barrel and remaining curtain can shift unexpectedly. Secure the barrel and remaining curtain before removing slats.
Replacement slats must be the exact manufacturer match — correct profile (flat slat, curved slat, insulated), material gauge, and width. Mismatched slats will not interlock properly, can jam in the guides, and may compromise the door's fire rating if applicable.
For fire-rated rolling doors, any curtain repair or replacement must maintain the door's original fire rating. Use only listed replacement parts from the manufacturer. Perform a drop test after any curtain work on a fire-rated door to verify proper closure.
Curtain slats have sharp edges that can cause deep lacerations. Wear cut-resistant gloves and long sleeves at all times when handling slats.
Required PPE
- Safety glasses
- Hard hat
- Cut-resistant gloves
- Steel-toed boots
- Long sleeves
- High-visibility vest (if in traffic area)
Tools Required
- Replacement curtain slats (correct profile, gauge, and width for the door)
- Socket set and wrenches
- Screwdrivers (flat and Phillips)
- Drill with metal bits
- Rivets and rivet gun (for slat-to-bottom-bar attachment)
- Pliers and tin snips
- Pry bar (flat)
- Rubber mallet
- Wire brush
- Tape measure
- Step ladder or scaffold / lift (for high doors)
- Lubricant (light machine oil for guides)
- Safety wire or cable for barrel restraint
- C-clamps or locking pliers
Procedure — 9 Steps
Step 1
Assess the Damage and Order Replacement Slats
Replacement slats must be the exact manufacturer match — correct profile (flat slat, curved slat, insulated), material gauge, and width. Mismatched slats will not interlock properly, can jam in the guides, and may compromise the door's fire rating if applicable.
With the door closed, identify all damaged slats by counting from the bottom bar up. Record the slat profile type (flat, curved, or insulated), material gauge, slat width (face dimension), and the door's overall width. Count the number of slats that need replacement. Order exact replacement slats from the door manufacturer or an authorized distributor. Verify the replacements match before beginning work.
Pro Tips
- Count damaged slats from the bottom bar up and note their exact positions — this tells you whether it is faster to work from the bottom up.
- Record all four ordering dimensions together: profile type, material gauge, slat face width, and overall door width. A missing dimension means a wrong order and a return trip.
- Photograph the damaged area and the interlock profile before ordering — it documents the exact slat style for the manufacturer or distributor.
- For fire-rated doors, confirm the replacement slats are manufacturer-listed parts so the door's fire rating is preserved.
- Do not begin removal until the exact replacement slats are on hand and verified against the existing curtain.
Checklist
References & Standards
- DASMA Technical Data Sheets
- Door manufacturer curtain replacement guide and parts catalog
- IDA / Longen Foundation — Rolling Door Safety