What a floor spring actually is
A floor spring is a hydraulic closer mounted vertically inside a steel housing recessed into the floor under the door. The door pivots on a spindle that rises out of the unit. When the door opens, the spindle rotates a steel cam that compresses a heavy spring and pushes hydraulic fluid through valves. When you release the door, the spring pushes the fluid back through the valves — that controlled fluid flow is what closes the door at a steady speed.
Floor springs are favoured on aluminium-framed entrance doors and on APG (all-purpose glass) doors because they keep the closer hidden, work with heavy door leaves, and survive high opening counts. Common UK brands: Dorma BTS80 / BTS84, Geze TS500, Briton 1000-series, Adams Rite.
Sign 1: fluid weep at the cover plate
A dark stain on the floor under the threshold, or visible oil sheen seeping out of the cover plate, means the floor spring's internal seals are failing. Hydraulic fluid is being pushed out under pressure each time the door closes.
Once a floor spring starts to leak it deteriorates quickly — usually weeks, not months, before closing function fails outright. Replace early. A planned daytime swap is half the cost of an emergency callout when the door fails completely.
Sign 2: door slams or stops short
The closing-speed and latch-speed valves inside the unit control the door's descent. As internal valves wear or the spring loses tension, these adjustments lose effect. The door either slams home in 2 seconds (over-speed) or stops short of the latch (under-speed). Try the valve adjustments first — a five-minute fix when the unit is still healthy. If the adjustment has no effect, the spring or seals are at end of life.
Sign 3: pivot play or wobble
Stand at the door and rock the top of the leaf side-to-side gently. A healthy floor spring keeps the door square. A worn pivot lets the top of the door drift — sometimes by 10 mm or more. This is usually the top centre (the pivot at the head of the frame, not the floor spring itself), but extreme play can indicate the floor spring spindle is worn too.
Top centre replacement is a separate job — typically 1 hour and around £200–£350. If the floor spring is also failing, the engineer will quote both as a paired replacement to avoid two callouts.
What floor spring replacement involves
The door comes off its pivots. The cover plate lifts. The old unit is removed from the floor housing. The new unit is set on shims to align the spindle dead-vertical with the new top centre. The door is rehung, set square, and the closing-speed and latch-speed valves are tuned to BS EN 1154 standards. The cover plate goes back on flush with the floor.
Typical timing: 2–3 hours on site for a single door. Cost: £500–£900 fitted, depending on brand and whether the top centre also needs replacing. We try to schedule outside trading hours where the door must stay in service.
Maintenance that extends floor spring life
Annual inspection. Closing-speed and latch-speed valve adjustment if the door has drifted from spec. Cover plate fixings checked and tightened. Threshold strip inspected and replaced if worn (a worn threshold lets water reach the floor spring housing — the fastest way to ruin a spring). On six-monthly intervals for high-traffic retail.