2mm Aluminium Sloping Coping - Left Handed Closed Stopend | 125mm External Leg - Online Metal Store Ltd

2mm Aluminium Sloping Coping - Left Handed Closed Stopend | 125mm External Leg

£59.52
(£71.42 Inc VAT)

2mm Aluminium Sloping Coping - Left Handed Closed Stopend | 125mm External Leg

The 2mm aluminium sloping coping system comes in two external leg sizes: 100mm and 125mm. The profile is the same, the slope is the same, and the installation method is the same. The difference is in the overhang: 125mm of external leg versus 100mm gives a more prominent drip detail, a wider visual profile on the finished parapet, and a slightly more positive throw of water clear of the wall face below. For projects where the parapet wall construction is wider, where the architectural specification calls for a more substantial coping profile, or where the housebuilder standard is set at 125mm, the 2mm sloping coping lengths in the 125mm system are the correct choice and this left handed closed stopend is the terminal component that completes the left end of each run in that system.

This product is the left handed closed stopend for the 2mm aluminium sloping coping range with a 125mm external leg. It is the wider-leg companion to the 100mm external leg left handed stopend, covering parapet installations where the wider leg size has been specified. Available in a range of sizes to suit the greater overall girth that a 125mm leg produces, and powder coated in any RAL colour at the Chelmsford facility to match the rest of the system.

100mm or 125mm External Leg: Choosing the Right System

Both leg sizes are available in the full 2mm aluminium sloping coping range and both use the same profile, slope angle, bracket system and installation method. The choice between them is driven by three considerations: wall width, architectural specification, and visual proportion.

Wall Width and Proportion

The external leg overhang should be in proportion to the wall it caps. On a standard single-skin brick or block domestic extension with a parapet wall width of around 100-150mm, a 100mm external leg gives a balanced profile. On a wider wall, a cavity wall construction with insulation, or a commercial parapet built to a larger wall thickness, the 100mm leg can look narrow and under-scaled against the wall width. The 125mm leg gives a more substantial profile on these wider constructions and is more commonly specified on new-build housing developments where parapet wall thicknesses tend to be greater than on single-skin domestic extensions. If in doubt, hold a 125mm coping length against the wall before ordering: the visual proportion will tell you which leg size is right for the job.

Architectural and Housebuilder Specification

Many housebuilders and architects specify a minimum external leg dimension for sloping coping on their standard house types or project specifications. A 125mm minimum external overhang is common on new-build housing across the South East and the Home Counties, particularly on two-storey properties and on developments where the parapets are prominent in the streetscape. If the project has a written specification, check the coping leg dimension before ordering. If it says 125mm, this is the system.

Water Throw-Off Distance

A 125mm external leg throws water 25mm further clear of the wall face than a 100mm leg. On a rendered or painted wall finish below the parapet, that 25mm matters: a coping that discharges rainwater too close to the wall face can cause staining, efflorescence and surface degradation below the drip line over time. On an exposed site in the South East where driving rain is a regular occurrence, the wider leg is a practical as well as a proportional choice.

Left Handed: A Quick Reminder

If you have arrived here directly rather than from the 100mm left handed stopend page, here is the key point on handedness: stand outside the building and face the parapet. The end of the coping run on your left needs the left handed stopend; the end on your right needs the right handed stopend. The two ends of every straight run require opposite hands. Most parapet runs need one left handed and one right handed stopend per run.

The handedness is determined by the sloped profile of the coping: the left handed stopend is fabricated to close the left terminal of the run with the end face following the slope in the correct direction for that end. Using the wrong hand on an end means the slope of the stopend end face will not align with the slope of the coping run, and the joint will not close correctly. The right handed closed stopend for the 125mm system is available as a separate product and should be ordered at the same time as this left handed version so both arrive colour-matched in a single delivery.

Product Overview

This left handed closed stopend is part of the Online Metal Store Ltd 2mm aluminium sloping coping range with a 125mm external leg, manufactured in Chelmsford, Essex. It caps the left terminal of a 125mm sloping coping run with a fully formed, sealed closure that follows the sloped profile exactly, with the 125mm external leg matching the overhang of the straight lengths and the 75mm internal leg returning down the inside face of the parapet. The full range of sizes covers the wider coping girths that the 125mm leg produces: for a given wall width, the overall coping girth on the 125mm system is 25mm wider than on the 100mm system, which means the stopend sizes for this system are correspondingly larger than their 100mm equivalents.

All components in this system are powder coated using an external grade polyester finish in any RAL colour. This stopend is fabricated to order in the size and RAL colour you specify, alongside the sloping coping lengths, corners, the right handed stopend, and any upstand stopends required for the same project. Everything is finished in the same batch at the Chelmsford facility so all components arrive in matching colour and profile.

Key Benefits

Wider Overhang for Positive Water Clearance

The 125mm external leg projects further beyond the outside face of the parapet wall than the 100mm version, carrying water clear of the wall face and reducing the risk of water running back against the wall below the drip edge. On a rendered, painted or fair-faced brick wall below the parapet, keeping the discharge point well clear of the surface is a long-term maintenance advantage. The wider leg achieves this without any change to the installation method or the bracket system.

Matched Profile Across the Full 125mm System

The left handed closed stopend is fabricated to the same sloped profile as the 125mm sloping coping lengths, so the junction between the stopend and the final straight length is flush and consistent. The slope angle, leg depths and overall profile dimensions match across every component in the 125mm system, whether ordered as part of a full perimeter package or individually as replacement components.

Fully Sealed Closed End Face

The closed design means the end face of the coping run is formed as a solid sealed closure with no open section, no exposed edge and no gap for water ingress at the terminal point. Once fitted and sealed with the colour coded sealant at the joint to the straight length, the left end of the 125mm sloping coping run is weathertight on all sides and across the full service life of the installation.

Powder Coated in Any RAL Colour

Available in any RAL colour using the same external grade polyester powder coating specification applied to all other components in the Online Metal Store Ltd sloping coping range. Ordering this stopend alongside the lengths and the right handed stopend in the same colour means all three components are finished together in Chelmsford and arrive as a matched set. The powder coat is the only available finish on these products.

Made to Order in Chelmsford, Fast UK Delivery

Custom-fabricated at the Online Metal Store Ltd facility in Chelmsford to the size and RAL colour specified at the time of order. As a made-to-order item it is non-returnable unless faulty, which makes accurate measurement before ordering essential. UK manufacturing keeps lead times short for projects across Essex, London, the South East and the wider UK.

Technical Specifications

Material: 2mm grade aluminium

Profile: Sloping coping closed stopend

Hand: Left handed (terminates the left end of the run as viewed from outside the building)

External Leg: 125mm

Internal Leg: 75mm (standard across 125mm external leg sloping coping range)

Size Range: Confirm exact range from live listing expected range approximately 235mm upwards in 25mm increments based on 125mm leg system girth calculation

Finish: Polyester powder coating, external grade NOT anodised

Colour: Any RAL colour to order

Type: Closed (fully sealed end face)

Compatible System: 2mm Aluminium Sloping Coping | 125mm External Leg

Fabrication: Made to order - non-returnable unless faulty

Country of Manufacture: United Kingdom (Chelmsford, Essex)

How to Measure for the Correct Stopend Size

The stopend size must match the overall width of the 125mm sloping coping profile, not the wall width alone. The formula for the 2mm sloping coping with 125mm external leg and 75mm internal leg is:

  • Measure the wall width at the top of the parapet from outside face to inside face.

  • Add the external leg (125mm) and the internal leg (75mm) = 200mm.

  • Add both returns at 10mm each side: 10mm + 10mm = 20mm.

  • Total: wall width + 220mm = overall coping girth and stopend size. For example, a 215mm wide wall gives 215 + 220 = 435mm. A 265mm wide wall gives 265 + 220 = 485mm.

  • Note: this formula gives a result 25mm larger than the same wall width calculated for the 100mm external leg system (which uses wall width + 195mm). If you have previously ordered from the 100mm system for the same project, do not use the same stopend size for the 125mm system.

  • If the calculated size falls between two available sizes, order the next size up. On a made-to-order non-returnable product, fractionally oversized is always preferable to undersized.

  • Quickest method on site: measure the overall width of an installed 125mm straight coping length directly across the top surface. That measurement is the stopend size to order.

How to Fit a 125mm Left Handed Sloping Coping Stopend

The installation method is identical to the 100mm system. Fix the 4mm aluminium coping brackets along the full parapet run first, with a bracket within 150-200mm of the left run terminal. Ensure the bracket at the end of the run is set back far enough from the wall termination to allow the stopend to seat fully over the end of the final straight length. Confirm the slope direction of the installed run before pressing the coping down: the high point of the sloped profile faces the building, the low point faces outward, and the left handed stopend must be aligned with the run so its slope matches the slope of the lengths.

Offer the left handed stopend to the left terminal of the run and check the fit. The sloped end face of the stopend must align with the slope of the final straight length before sealing. Apply a continuous bead of colour coded sealant around the full internal perimeter of the stopend, then press it to its final position. The sealant bead at this joint is the primary weathertight seal at the run termination and must be continuous with no gaps.

Secure the assembly with colour coded fasteners in the matching RAL colour through the bracket bearing positions. Apply a finishing bead of sealant on the external joint face. The right end of the same run then receives the right handed closed stopend for the 125mm system in the same way.

Where the 125mm Left Handed Sloping Coping Stopend Is Used

New-Build Housing with Wider Parapet Walls

Volume housebuilders on NHBC-registered developments across Essex, the Home Counties and the wider South East frequently specify 125mm external leg sloping coping for houses with cavity wall parapets or insulated parapet constructions where the wall thickness exceeds what a 100mm leg would proportionally cover. On a development where the house type specification calls for 125mm, the stopends for each plot are ordered as part of the complete 2mm sloping coping 125mm system, ensuring colour consistency across every unit on the development. The aluminium sloped coping case study shows the sloping coping system installed at scale on a London residential development.

Domestic Extensions with Cavity or Composite Parapets

Rear and side extensions built with cavity wall or insulated parapet construction are common on semi-detached and terraced houses across the South East. The parapet wall on these builds is often 150mm or wider once the inner leaf, insulation and outer leaf are accounted for. On walls of this width, a 125mm external leg gives a better proportional profile and a more positive drip detail than the 100mm version. For homeowners and builders in Chelmsford, Brentwood, Basildon and across Essex specifying a coping system for an extension with a wider parapet, the 125mm system is worth considering against the 100mm before ordering.

Replacement Coping on Existing Wider Parapets

When replacing failed or damaged coping on an existing building, the replacement must match the original external leg dimension. If the existing coping on the building has a 125mm external leg, ordering a 100mm replacement will produce a visible mismatch in profile and overhang that is immediately obvious from the ground. For refurbishment projects on buildings where the parapet construction produces a wider coping girth, the 125mm system with this left handed stopend is the correct replacement specification. Both the 90 degree external corner and the 135 degree external corner are available in the same 125mm system for junctions and angles on the same refurbishment project.

Architectural Projects Requiring Prominent Coping Profile

On housing developments and residential projects where the parapet coping is a visible architectural element, the 125mm external leg gives a more deliberate, designed appearance than the 100mm version. The wider overhang casts a more defined shadow line below the parapet and produces a profile that reads more confidently at street level. For architects and developers specifying coping on a scheme where the parapet detail contributes to the streetscape quality, the 125mm system is the specification that delivers that result.

Frequently Asked Questions

What is the difference between the 100mm and 125mm external leg sloping coping systems?

The profile, slope angle, gauge and installation method are identical. The only difference is the length of the external leg: 100mm on the narrower system, 125mm on the wider. The 125mm leg gives a more substantial overhang, throws water further clear of the wall face, and produces a wider visual profile on the finished parapet. It is better suited to wider parapet wall constructions, new-build housing developments where the housebuilder specification calls for a 125mm minimum, and projects where a more prominent coping profile is specified. All stopends, corners and accessories in the two systems are separate products and are not interchangeable.

How do I calculate the correct stopend size for the 125mm system?

Add the wall width to 220mm. That figure accounts for the 125mm external leg, the 75mm internal leg, and 10mm returns on each side (125 + 75 + 10 + 10 = 220). A 215mm wide wall gives a stopend size of 435mm. A 290mm wide wall gives 510mm. If the result falls between two available sizes, order the next size up. Note that this formula gives results 25mm larger than the same wall width on the 100mm system (which adds 195mm rather than 220mm). Do not use the 100mm system sizing calculation for the 125mm system.

What does left handed mean on this stopend?

Stand outside the building and face the parapet. The end of the coping run on your left as you look at the wall needs the left handed stopend. The end on your right needs the right handed stopend. The handedness is fixed by the slope profile of the coping: the left handed stopend is fabricated to close the left terminal of the run with the end face following the slope in the correct direction for that end. Fitting the wrong hand reverses the slope at the terminal and means the joint will not close correctly. Every straight run needs one left handed and one right handed stopend.

Can I use 100mm system accessories on the 125mm system?

No. The stopends, corners and upstand stopends in the 100mm and 125mm systems are separate fabricated products and are not interchangeable. Although the slope angle and bracket system are the same, the leg dimensions differ, which means the profile dimensions of the accessories differ. A 100mm corner or stopend used on a 125mm coping run will produce a dimensional mismatch at the junction. Always order all accessories in the leg size that matches your coping lengths.

Is this product powder coated or anodised?

It is powder coated with an external grade polyester finish available in any RAL colour. It is not anodised. All products in the Online Metal Store Ltd sloping coping range are finished with polyester powder coating only. There is no anodising option. Specifying a RAL colour gives you a powder coated finish in that colour across every component in your order.

Part of a Complete 2mm Sloping Coping System | 125mm External Leg

This left handed stopend is one component in the complete 2mm aluminium sloping coping system with a 125mm external leg. Every straight run needs lengths, a left handed stopend and a right handed stopend, with corners and upstand stopends added for junctions and specific details. All components should be ordered from the same Chelmsford manufacturer to ensure consistent profile, colour and system compatibility. The full 2mm sloping coping system with 125mm external leg includes:

For the full sloping coping range overview across both 100mm and 125mm leg sizes, visit the Aluminium Sloping Coping collection page. If you are working with the 100mm external leg system, the left handed closed stopend for the 100mm system is the equivalent terminal piece for the narrower leg specification.

Standards and Compliance

Aluminium parapet coping systems in the UK, including sloping coping, are specified and installed in accordance with BS 6229:2018 - Flat Roofs with Continuously Supported Flexible Waterproof Coverings. The standard covers parapet and edge detailing requirements for flat roofs, including the correct termination of coping systems at run ends. A properly fitted and sealed left handed closed stopend at each left terminal of a 125mm sloping coping run is part of a complete and weathertight parapet detail consistent with the requirements of this standard.

The external grade polyester powder coat finish applied to all Online Metal Store Ltd sloping coping components is in accordance with BS EN 12206-1 - Organic Coatings on Aluminium and Aluminium Alloys. The coating standard applies consistently across the 125mm system as it does across the 100mm system and the flat coping range: same specification, same colour range, same durability requirements. All components in an order are coated to this standard in the same batch.

For NHBC-registered new-build projects, Chapter 7.1 of the NHBC Standards sets out parapet wall and flat roof construction requirements. On new-build developments where the house type specification calls for a 125mm external leg sloping coping, the complete system from lengths to stopends is consistent with those requirements and supports the NHBC warranty position on completion.

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Custom Fabricated Item

This is a custom-fabricated item made to your selected size and finish. Please double-check measurements before ordering. This product is non-returnable unless faulty, as explained in our Refund & Return Policy

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