A large rolling steel door that won't close or is hard to lift: causes and fixes

The short version

A large rolling steel door that is hard to lift has usually lost barrel spring tension. One that won't close usually has a curtain binding in bent guides, damaged slats, or a bottom bar catching on something. Don't force either. Retensioning or replacing the spring, straightening or replacing the guides, and swapping damaged slats fix most of these doors without replacing the curtain.

A heavy chain hoist almost always points to lost barrel spring tension
A curtain that stops partway down is usually binding in a bent guide
Bent or torn slats can often be replaced on their own
Forcing a jammed curtain bends more slats and makes the repair bigger
Damp air and a high water table rust guides and hardware faster in Richmond

How a rolling steel door carries its weight

A rolling steel door is a curtain of interlocking slats that winds onto a barrel above the opening. Inside that barrel is a spring that balances the weight of the curtain. As the curtain rolls up, the spring gives up tension. As it rolls down, the spring winds back. The guides on each side keep the curtain straight, and the bottom bar seals against the floor.

When any one of those parts is off, the door gets hard to move in one direction or the other.

When the door is hard to lift

If the chain hoist takes real effort, or the operator labours and slows near the top, the barrel spring has usually lost tension. Springs relax over years of use, and a spring that has lost tension leaves the hoist or motor carrying weight it was never meant to.

When the door won't close

A curtain that stops partway down or sits crooked usually has a mechanical cause:

Bent guides. A forklift or truck clips the guide, and it bends away from the wall or into the opening. The curtain catches where it narrows.
Damaged slats. A dented or torn slat won't slide past the guide and jams the curtain.
Bottom bar damage. A bent bottom bar or torn seal can hang up on the guides or hit the floor unevenly.
Debris and ice. Pallet wrap, gravel or a buildup in the guides can stop the curtain short.

Don't force it

It's tempting to pull harder on the chain or keep pressing the button. That bends more slats and can pull the curtain out of the guides altogether. Leave it where it stopped, keep people out from under it, and send a photo.

What we check and fix

We start by looking at the whole door: the guides, curtain, bottom bar, barrel, spring and the hoist or operator. Then we fix the cause, not only the symptom. A typical repair might include:

Straightening or replacing a bent guide and fixing it back to the wall
Cutting out bent or torn slats and fitting matching ones
Replacing a damaged bottom bar and its seal
Retensioning or replacing the barrel spring
Checking the chain hoist or operator, and setting the limits once the door moves freely

Most guide, slat and tension repairs take a few hours. Replacing a curtain section or the barrel takes longer.

Damp, wind and rust in Richmond

Richmond sits on flat delta land near sea level, and the high water table keeps ground and concrete damp through the wet season. Wind off the Strait of Georgia carries moisture onto doors from Steveston to East Richmond. Rolling doors on warehouses and yards here tend to show rust in the guides, on the bottom bar and around the barrel brackets sooner than doors further inland. Rust adds friction, and friction makes a door that's already short on spring tension even harder to move. Flat ground also means water can pool at a door with a worn bottom seal.

What to send before the visit

A quote comes together faster with:

The door's width and height
Whether it's chain-operated or motorised, and the operator brand if there is one
Photos of both guides, the bottom bar and any damaged slats

We plan the work around your shifts so only one door is out at a time, and you get a quote before any work starts.