How Pro-Lock assesses a bifold doorset

We start by taking a full account of the doorset: when it was fitted, what has changed since, what the door does now that it did not do before, and where in its operation the problem shows. The doorset’s history gives the engineer useful context for interpreting the symptoms and planning the assessment.

We ask about previous adjustments, repairs, replacement components, changes in the way the door is used and any change in weather performance or security. This timeline helps the engineer compare the history with the physical findings.

Why this matters: the engineer can relate the current fault to the doorset’s history and make a more informed repair recommendation.

We take extensive measurements across the frame and panels to establish whether the doorset is square and true, or whether it has moved. Distortion can be difficult to see, so measurements help establish the frame and panel condition accurately.

Measurements are taken at relevant points across the doorset so that movement can be distinguished from a local hardware fault. This establishes how the panels, frame and running arrangement relate, helping identify the repair or adjustment that best fits the condition.

Why this matters: measurements help match the recommended work to the frame and panel condition.

The engineer checks frame square and twist because these measurements affect how panels sit, meet, seal and lock. Understanding the frame geometry helps establish which adjustments can support stable panel movement.

Square describes whether the frame and panels hold the intended geometry; twist describes a change through the depth or height of the frame that can affect how the panels meet, seal and lock. These checks are important where a doorset appears close to correct in one position but catches or resists elsewhere in its travel.

Why this matters: understanding frame geometry helps identify adjustments that can support stable panel movement and alignment.

We test the doorset through opening, closing, folding and locking, observing how it moves under load and how the panels meet throughout the operating cycle.

The engineer observes the force, movement and contact points through the operating cycle. A panel can look aligned while stationary but move, bind or load the hinges, rollers, guides or locking points when the weight of the panels is being carried during operation.

Why this matters: the assessment considers the door’s movement during everyday operation, helping identify the conditions behind the fault.

We check drainage routes and how water moves through the threshold, helping protect the frame, seals and hardware from trapped or misdirected water.

The assessment follows where water should enter, travel and exit, and checks the threshold, seals and surrounding hardware together. This helps identify the repair that will restore the intended drainage path.

Why this matters: checking drainage alongside seals and adjacent components helps the repair recommendation address the route water is taking.

Glazing, gaskets and manufacturer-specific glazing packers are inspected to understand how they support the panel and its alignment. Correct toe and heel glazing helps keep the panel square and level, supporting smooth movement and reducing strain on the hardware.

The engineer checks how the glass, gaskets and packers are supporting the panel and how that condition relates to alignment, contact pressure and operation. These checks are especially useful when a panel has dropped, a lock has become difficult or a door has started to drag, because glazing support can affect panel position and operation.

Why this matters: checking glazing support alongside the hardware helps establish how panel position and operation are connected.

Where parts are involved, we verify the fitted component and part numbers against manufacturer information, then check the compatible repair options and availability.

The assessment identifies the hardware in context, including the relationship between the component, the profile, the configuration and the rest of the doorset. For older, unbranded or mixed-component systems, this step helps confirm the fitted hardware and identify a compatible repair route.

Why this matters: checking component compatibility helps ensure any part quoted is suitable for the doorset and its working load.

Every measurement and observation is then cross-checked against the manufacturer's recommended tolerances. This helps establish whether the doorset is within tolerance and whether adjustment, compatible parts or a more extensive repair route is appropriate.

The cross-check brings the separate findings together. The combined findings guide the repair recommendation, including any component replacement or more extensive work that may be appropriate.

Why this matters: comparing the findings with the manufacturer’s tolerances supports a recommendation grounded in the doorset’s design.

Once the measurements and observations have been checked against the manufacturer’s guidance, we prepare an itemised quotation based on the doorset’s assessed condition.

The quotation sets out the recommended repair work and the relevant components or labour required, subject to suitable parts being available. The written report explains the recommended work and any limits on the available repair options.

Why this matters: your written recommendation explains the proposed work and gives you time to review it before arranging a repair.