51 long-form guides written by our engineers. Diagnose faults, understand maintenance, plan compliance — or jump straight to the topic that matches your problem.
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Why your commercial door is misbehaving — the most common faults explained in plain language.
Aluminium shopfront doors fail gradually. Catching the early signs — a dragging bottom rail, a sluggish close, fluid on the floor under the transom — lets you fix a worn pivot or closer before the frame, glass or hinges take collateral damage.
Read guide Guide · 5 min readA shopfront door that will not close on its own latch is rarely just “a stiff hinge”. It is almost always one of five specific faults — and the right fix depends on which one.
Read guide Guide · 5 min readDoor closers are wear parts. A correctly-installed closer on a moderately busy door lasts 5–10 years. On a high-traffic retail entrance, three years is more typical. The reasons are predictable.
Read guide Guide · 5 min readA dropped aluminium door usually means the bottom pivot, top centre or transom closer has lost alignment or worn through. Diagnosing which lets you swap one component instead of writing off the door.
Read guide Guide · 5 min readCommercial glass doors fail in three distinct ways: edge chips that propagate, frame or hardware stress that warps the glass, and impact damage from carts and deliveries. The right response depends on which.
Read guide Guide · 4 min readA misaligned shopfront door drags, sticks, fails to latch, and chews through closers and pivots. The underlying cause is usually one of three things — and all are fixable without replacing the door.
Read guide Guide · 4 min readA door that will not lock leaves a building uninsured and exposed. The fastest path to a working lock is identifying which of four components has failed — usually one is obvious from the symptom.
Read guide Guide · 6 min readAutomatic doors fail in patterns. Sensor faults, drive-belt slip, control-board lock-up and safety-beam misalignment account for the large majority of callouts. Knowing the pattern speeds up the fix.
Read guide Guide · 4 min readSmall commercial door faults compound. A dragging door wears the closer. A worn closer slams the door. A slammed door cracks the glass. Catching the first symptom is far cheaper than catching the third.
Read guide Guide · 5 min readAlmost all commercial doors can be repaired. The handful of situations where replacement is the right call — frame corrosion through, structural deformation, irreparable glazing — follow a clear pattern. Here is how to tell.
Read guide Guide · 5 min readFloor springs sit invisibly under the threshold of most aluminium-framed and APG glass commercial doors. They are the most common closer on shopfronts in the UK — and when they fail, the door usually fails with them. Knowing how they work and what failure looks like avoids the £500 repair becoming a £1,500 emergency callout.
Read guide Guide · 5 min readA transom closer is the hydraulic unit hidden inside the metal bar at the top of an aluminium-framed door — the "transom". You only see it from above when the cover lifts off. When transom closers fail they take a few weeks of warning to do it, and the symptoms look very different from a floor spring or overhead closer.
Read guideEvery commercial door type we work on, with the typical faults and how we fix them.
Commercial doors are a category, not a product. Aluminium shopfronts, automatic sliders, roller shutters, fire doors and steel security doors each fail differently and each needs different parts. Here is the full landscape in one place.
Read guide Guide · 5 min readAutomatic doors are mechanical, electrical and electronic in one box. Most callouts trace to a handful of well-understood faults. Some you can clear by clearing the threshold; others need engineer time on the controller.
Read guide Guide · 6 min readRoller shutters protect more value per square foot than any other door type on a commercial site. They also fail in predictable ways — motor wear, broken springs, jammed slats, controller lock-out — and most can be repaired in situ.
Read guide Guide · 6 min readHigh-street shopfronts and shopping-centre units share a lineage of common door types: aluminium frames with transom closers, APG glass entrances, automatic sliders. The fault list is short. The repair playbook is well-established.
Read guide Guide · 6 min readHinges, locks and closers are the three wear-part categories on every commercial door. Each has a different lifespan, different failure modes, and a different repair-vs-replace calculation. Here is the engineer-level breakdown.
Read guide Guide · 5 min readSliding automatic doors handle more openings per day than any other type of commercial entrance. Drive belts stretch, top tracks pick up debris, safety beams drift out of alignment. The repair set is well-defined.
Read guide Guide · 5 min readAluminium-framed and APG glass shopfront entrances are the two dominant door types on UK high streets. Both share a common hardware vocabulary — pivots, closers, locks — and both can be repaired without replacing the door.
Read guide Guide · 5 min readHinges are the unglamorous half of commercial door hardware. They never get the attention closers, locks or panic hardware get — right up until one fails. A failed hinge is a dropped door, a damaged frame, and on a fire door a compliance breach. Here is what you need to know.
Read guide Guide · 5 min readAPG — all-purpose glass — doors are the frameless or minimally-framed glass entrance doors on premium retail, restaurants and showrooms across the UK. They look simple. They are not. The hardware is precision-engineered, mostly bespoke per manufacturer, and repair is one of the hardest disciplines in commercial door work.
Read guide Guide · 6 min readA busy high street shopfront entrance rarely fails on a single component. By the time the transom closer is sluggish, the bottom pivot has usually dropped and the drive arm has worn — and the latching plate and stop block have drifted with the door. This guide explains why the three components fail together, what a proper repair looks like, and the order of operations that makes it a one-visit job. Drawn from a real CDMS Ltd repair completed at Boots Opticians in Horley, Surrey RH6 7AY.
Read guideHow preventative maintenance and service contracts cut downtime and total repair cost.
A commercial door that keeps failing is almost always a door that was repaired but never tuned. Replacing the broken part without resetting closing speed, latch action and pivot alignment guarantees the next failure inside 12 months.
Read guide Guide · 5 min readCommercial door maintenance is not a tick-box exercise. Scheduled servicing catches wear early, keeps insurance valid, satisfies fire safety compliance, and reduces total repair spend over the door’s life.
Read guide Guide · 5 min readUK weather is the slow background driver behind most commercial door wear: wind load loosens fixings, thermal cycling expands and contracts aluminium, salt air corrodes coastal hardware, water ingress rots seals.
Read guide Guide · 5 min readMost expensive door repairs are preventable. A simple split of daily/quarterly/annual tasks — some for in-house staff, some for an engineer — cuts the annual repair spend on a typical commercial door by half.
Read guide Guide · 5 min readA maintenance contract is a cashflow exercise. Fixed quarterly visits replace unpredictable emergency callouts, priority response moves you to the front of the queue when it does matter, and documentation satisfies insurers and regulators.
Read guide Guide · 4 min readService intervals depend on door type and traffic level, not calendar guesswork. Here is a realistic schedule by door type, plus the statutory minimums for fire doors that you cannot push past.
Read guide Guide · 5 min readA pre-acquisition door survey isn't a standard part of a commercial property purchase. It probably should be. Doors fail in predictable, expensive ways — and the previous tenant or owner has every reason to leave the worst examples to whoever takes the property next. Half a day of engineer time before exchange of contracts pays for itself many times over.
Read guideOut-of-hours response, emergency boarding, and same-day repair for security-critical sites.
A failed commercial door is a security and trading emergency. Same-day response, photo-led remote diagnosis and the right parts on the van first time are what separates an emergency callout from a holding fix.
Read guide Guide · 5 min readSchools, hospitals and offices each have unique repair constraints: safeguarding, infection control, business continuity. Fast does not mean rushed — it means scheduling and clearance handled correctly so the work fits the building.
Read guide Guide · 4 min readEmergency boarding is the bridge between a forced-open door at 9pm and a permanent repair the next morning. Done properly, it secures the building, satisfies the insurer and preserves evidence for the police claim.
Read guide Guide · 5 min readWhen a commercial door is damaged in an incident — break-in, ram-raid, vehicle impact, vandalism — the insurer is going to be involved. How the immediate response is handled, what is documented, and which engineer is engaged can speed or slow the claim by weeks. Here is the engineer-side view of how to do it cleanly.
Read guideFire door compliance, security upgrades, lock and access control faults.
A broken door is not a cosmetic problem. It can void building insurance, breach fire safety law, create personal-injury liability, and signal vulnerability to opportunist crime. The path back to compliance is usually straightforward.
Read guide Guide · 7 min readFire door compliance is non-negotiable under the Regulatory Reform (Fire Safety) Order 2005. Most fire doors fail inspection on five repeatable items — intumescent strip, smoke seal, signage, gap tolerance, closer action. All five are repairable.
Read guide Guide · 5 min readA repair visit is the cheapest moment to upgrade security. The door is open, the engineer is on site, and most security upgrades (anti-thrust plate, hookbolt lock, reinforced strike) are an hour’s extra work over the original fault.
Read guide Guide · 5 min readOffice entrance doors sit at the intersection of two competing requirements: security strong enough to keep the building safe, and accessibility light enough to satisfy the Equality Act 2010. Both can be met simultaneously.
Read guide Guide · 6 min readLocks and access control fail at the interface between mechanical hardware and electronics. Diagnosing whether the fault is in the lock body, the controller, the reader or the wiring is the first job on every callout.
Read guide Guide · 5 min readSecurity doors are graded — LPS 1175, Secured by Design, Police Preferred Specification — and repairs must preserve the rating. Done correctly, a damaged security door comes back to its original spec without certificate loss.
Read guide Guide · 6 min readPanic hardware is the bar, lever or paddle on an emergency exit door that lets people out under pressure. It is a life-safety component and it is heavily regulated. Two British and European standards cover it — BS EN 1125 and BS EN 179 — and choosing the right one is a Responsible Person decision under the Fire Safety Order.
Read guide Guide · 6 min readThe Equality Act 2010 places a duty on UK service providers, employers and landlords to make "reasonable adjustments" for disabled users. Where the entrance door is a barrier — too heavy, too narrow, unusable from a wheelchair — that duty applies to the door. The technical specification of what counts as accessible is in BS 8300.
Read guideSector-specific guidance for retail, hospitality, healthcare, schools, warehouses and managed property.
High-traffic doors fail predictably. The closer goes first, then the pivot, then the latch. Knowing the order lets a facilities manager plan a rolling replacement programme that prevents the cascade entirely.
Read guide Guide · 6 min readWarehouse and industrial entrance doors run a different lifecycle to retail shopfronts: heavier loads, vehicle impact, tighter security needs, longer downtime cost. The repair playbook is correspondingly different.
Read guide Guide · 5 min readHospitality venues hit doors hard: high front-of-house traffic, regulated fire compartmentation, food-hygiene zoning, and reputational risk if anything blocks customer flow during service.
Read guide Guide · 4 min readA scratched, dragging or scuffed shopfront door is the first thing a customer touches. The brand spends fortunes on the shop interior; the door is a brand-touch the brand barely thinks about until customers do.
Read guide Guide · 6 min readCommercial property managers and landlords carry door responsibilities written into leases, covenants, and the Regulatory Reform (Fire Safety) Order 2005. Knowing what sits on you vs the tenant prevents the most common disputes.
Read guideWhat to look for in a commercial door engineer, and the cost of DIY shortcuts.
Retail door buyers have a specific shopping list of questions before commissioning a repair: how fast, how much, what guarantee, do you carry the brand, can you work after hours. Direct answers below.
Read guide Guide · 5 min read“Commercial door repair near me” usually returns a mix of national chains, white-label resellers and one-van outfits. The criteria that separate a reliable contractor from a bad-Tuesday operator are short and worth knowing.
Read guide Guide · 5 min readDIY commercial door repair has three failure modes: voiding the manufacturer warranty, breaching fire safety compliance, and chasing the symptom instead of the cause. All three are more expensive than a professional engineer visit.
Read guide Guide · 5 min readCommercial door repair pricing varies more than most building trades. The same fault on the same door can cost £200 or £1,500 depending on what is replaced, how urgent it is, who attends, and what parts get sourced. Here is what actually drives the price in 2026 UK rates.
Read guide Guide · 6 min readA new commercial entrance is a long-term decision — 15–25 years of daily use, weather exposure, regulatory obligations and brand impression. The cheap version is rarely the best value. The premium version is rarely necessary. Here is what actually matters when you are specifying.
Read guideA two-minute call with one of our engineers usually solves it. Same-day quote from a description, photo or short video.
Get in touch
Head Office:
Commercial Door Maintenance and Security Ltd
61 Bridge Street,
Kington,
HR5 3DJ
t: 0800 774 7998
e: info@cdms-ltd.co.uk
Office Hours
Mon - Sat: 8am - 10pm
Sun: Closed
