Included, and what it is not
- ✓ Check the prepared opening is square and the lintel is already in
- ✓ Set the frame and the threshold
- ✓ Hang the panels and adjust the rollers
- ✓ Align locks and meeting stiles
- ✓ Seal the frame to the opening
Ways this job is specified
Aluminium sets
The usual external bi-fold. Panel count and width drive both the door price and the fitting time.
Timber bi-folds
Heavier to handle and more sensitive to an opening that is out of square.
Internal room dividers
A track and lighter panels between two rooms. No weather threshold, but the head track still has to be fixed into something solid.
Traffic doors
One panel in the set is the everyday door. It needs its own lock alignment, not just a free-running track.
On the day
01
Opening check
Width, height, diagonal and the threshold level. An out-of-square opening makes the end panel stand proud no matter how the rollers are tweaked.
02
Frame and track
The threshold is set so water leaves the building. The head track is fixed so the panels do not drop in the middle of a wide span.
03
Panels
Rollers, hinges and the traffic door are adjusted until every panel closes on the seal and the lock throws without lifting the door.
What changes the price
The door set is most of the money. A modest timber or aluminium bi-fold supplied and fitted often sits in the low thousands; wide multi-panel aluminium sets cost more. Fitting labour depends on panel count, weight, and whether the opening is already square and weathered. If a builder still has to form the opening and the lintel, that is their cost, not part of the hang. We quote from width, panels and the state of the opening.
Symptoms people search
Panels that stick at one end mean the opening is out of square or the threshold has dipped. A traffic door that will not lock usually means the frame has moved, not that the lock is “stiff”. Water on the inside floor is a threshold or a missing seal, not something a new handle will fix. Squealing rollers are dirt or a panel that has dropped on its hinge.
Before and after the hang
The opening should be built, the lintel in, and the external base ready before we arrive. Indoors, clear a full panel-width of floor. After installation, keep grit out of the track and do not hang weight on a single panel. Timber sets need their edges finished as the maker specifies so they do not swell and leave the track.
What fails later
Rollers, hinges and locks wear with use. A wide set that was forced into a crooked opening will keep needing adjustment. Tracks full of grit chew the rollers. External gaskets perish in sun and salt and are replaceable; the panels themselves last if the frame was set square.
Doing it yourself
A small internal bi-fold in a square timber opening is sometimes a DIY job. External aluminium sets are heavy, the threshold has to shed water, and a wrong diagonal is expensive to undo. We install into a prepared opening. We do not cut the structural opening.
Outside this job
- We do not design or install the steel or concrete lintel
- We do not remove a structural pier or widen the opening
- We do not fit the bi-fold as a substitute for a proper cavity tray and external seal
- Internal pocket doors are on the sliding-door page
Questions about bi-fold door installation
No. The opening and the lintel need to be in place first. We fit the door set into that opening.
As many as the opening and the chosen system allow. More panels mean more rollers and a longer adjustment, which is reflected in the quote.
The threshold has to be set to the system, usually with a fall to the outside. A dip in the middle makes the centre panels catch.
French doors are a pair on hinges. Bi-folds stack to one or both sides on a track. French doors are a separate page.
Yes, if the set is straight enough to adjust. If the opening is badly out of square, adjustment will not fix it.
A prepared domestic opening is often a day. Wider sets and openings that need packing take longer.
Other door jobs
Quote for bi-fold door installation
Say how many doors, whether you have already bought them, and the town. We reply with a written quote.