3mm Aluminium Sloping Coping – Closed Stopend (Left Handed) | 100mm External Leg - Online Metal Store Ltd

3mm Aluminium Sloping Coping – Closed Stopend (Left Handed) | 100mm External Leg

£73.92
(£88.70 Inc VAT)

3mm Aluminium Sloping Coping – Closed Stopend (Left Handed) | 100mm External Leg

The size range on this product, 510mm to 1060mm, is not arbitrary. It reflects the parapet wall widths this product is designed for: cavity wall commercial construction, new-build housing with insulated parapets, and wider building envelopes where the coping girth exceeds what a domestic single-skin extension produces. You would not order a 510mm sloping coping stopend for a 100mm single-skin garden wall. You order it for a 315mm commercial parapet on an office development in Chelmsford or a new-build semi in Basildon with an insulated cavity parapet. And you specify 3mm because on a commercial building, an NHBC-registered development, or an exposed site on the Essex or Kent coast, the heavier gauge is the correct specification for the service life expected of the installation.

This is the left handed closed stopend for the 3mm aluminium sloping coping system with a 100mm external leg. It terminates the left end of a 3mm sloping coping run with a fully sealed, weathertight closure, matched exactly to the sloped profile of the 3mm sloping coping lengths. Manufactured in Chelmsford, Essex, available in any RAL colour, and non-returnable as a custom-fabricated item. Get the size and the hand right before ordering.

2mm or 3mm Sloping Coping: Choosing the Right Gauge

The sloping coping profile is available in both 2mm and 3mm gauge at Online Metal Store Ltd. Both systems share the same slope angle, the same 100mm external leg dimension, and the same bracket fixing principle. The gauge choice follows the same logic as for flat coping: project type, site exposure, and what the specification calls for. Use the 2mm sloping coping system for domestic flat roof extensions, sheltered residential parapets, boundary walls and garden structures where a lighter gauge is appropriate and budget is a consideration. Use the 3mm system for:

  • Commercial buildings: offices, retail units, light industrial buildings, mixed-use developments, and any project where a structural or architectural specification has been produced.

  • NHBC-registered new builds where the parapet detail on the house type specification calls for 3mm coping.

  • Exposed and coastal sites: buildings within a few kilometres of the Essex, Suffolk or Kent coast, open-aspect sites exposed to prevailing winds, and elevated buildings where wind uplift forces at the parapet are higher than at ground level.

  • Wider parapet walls: the 3mm system size range (510mm–1060mm) reflects the wider commercial wall constructions this product is designed for. If the overall coping girth on your project falls in the 510mm–1060mm range, you are almost certainly in commercial or wider-spec residential territory, and 3mm is the right gauge.

  • When the structural engineer or specifier has called for 3mm in the project documentation.

Both gauge systems are available with the same RAL colour options and the same Chelmsford manufacturing lead times. Mixing gauges on the same installation is not recommended: a 2mm corner or stopend cannot be used with 3mm lengths. Every accessory must match the coping gauge. For the 3mm system, always use the 5mm coping bracket, not the 4mm bracket, which is specified for the 2mm system.

Left Handed: Which End of the Run

Stand outside the building and face the parapet. The left end of the coping run as you look at the external wall needs the left handed stopend. The right end needs the right handed stopend. Every straight coping run needs one of each. If you need the full explanation before ordering, the 2mm sloping coping left handed stopend page includes a step-by-step handedness guide. The method is identical for the 3mm system. The companion to this product, the right handed closed stopend for the 3mm 100mm system, should be ordered at the same time in the same RAL colour so both arrive together and the run can be closed out in a single installation sequence.

Product Overview

This left handed closed stopend is part of the Online Metal Store Ltd 3mm aluminium sloping coping system with a 100mm external leg. It is fabricated at the Chelmsford facility to order in the size and RAL colour specified, and it caps the left terminal of a 3mm sloping coping run with a fully formed, sealed closure that follows the sloped profile exactly. The 100mm external leg provides the overhang and drip detail for water clearance; the 75mm internal leg returns down the inside face of the parapet. The 23 available sizes, from 510mm to 1060mm in 25mm increments, are calibrated for commercial parapet wall widths from approximately 315mm up to approximately 865mm, the wall width range typical of commercial flat roof construction and wider residential cavity parapet builds.

All components in the 3mm sloping coping system are powder coated with an external grade polyester finish in any RAL colour. Ordering this stopend alongside the 3mm sloping coping lengths, the right handed stopend, and the corner pieces for the same project means all components are finished in the same RAL colour in the same Chelmsford batch and arrive as a colour-matched system.

Key Benefits

Heavier Gauge for Commercial and Exposed-Site Performance

The 3mm gauge provides greater rigidity and wind uplift resistance than the 2mm equivalent. On a commercial parapet at any height above ground level, the wind loads acting on the coping face and overhang are higher than on a sheltered domestic extension. The 3mm stopend matches the stiffness of the 3mm coping lengths it terminates, so the end of the run is no weaker than the run itself. On an exposed site in the South East, on a building of two or more storeys, or on a site where the structural engineer has been involved in the parapet specification, the 3mm gauge is the correct choice for every component in the system.

Profile-Matched to the 3mm Sloping Coping System

A sloping coping stopend must follow the slope angle of the coping profile exactly. This stopend is fabricated to the same sloped profile as the 3mm sloping coping lengths with a 100mm external leg, so the junction between the stopend and the final straight length is flush, tight and consistent with the slope direction of the installed run. The end face of the stopend follows the slope: the high point aligns with the high side of the coping, the low point aligns with the low (external, draining) side.

Fully Sealed Closed End, No Exposed Edge

The closed design seals the end face of the 3mm sloping coping run as a solid, fully formed closure. There is no open section, no exposed aluminium edge at the terminal point, and no gap for driven rain to enter the system at the run end. Once the stopend is sealant-bedded and fixed against the final straight length, the left terminal of the run is as weathertight as the rest of the installed system. On a commercial parapet on an exposed south-facing elevation, this matters considerably.

Commercial Size Range: 510mm to 1060mm

The 23 available sizes from 510mm to 1060mm in 25mm increments cover commercial parapet wall widths from approximately 315mm to 865mm. This is the wall width range produced by cavity wall construction, insulated parapet builds, and commercial structural parapets. It is not the domestic single-skin range, which is covered by the 2mm sloping coping system. The size calculation guide below explains how to determine the correct stopend size from the wall width measurement.

Powder Coated in Any RAL Colour, Not Anodised

The finish on every component in the 3mm sloping coping range, including this stopend, is an external grade polyester powder coat available in any RAL colour. These products are not anodised. Powder coating and anodising are different finishing processes. The current product page contains several incorrect references to anodising that must be removed: these products are powder coated only. Specifying a RAL colour at the time of order gives a consistent powder coated finish across every component in the order.

UK Manufactured for Commercial Programme Certainty

Made to order at the Online Metal Store Ltd facility in Chelmsford, Essex, with UK manufacturing lead times that support commercial construction programmes. Non-returnable as a made-to-order custom fabrication. For commercial projects in Essex, East London, the South East and the wider UK, the system components can be ordered as a package and delivered on a programme that keeps the coping installation on the critical path to watertight.

Technical Specifications

Material: 3mm 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: 100mm

Internal Leg: 75mm (standard across the 100mm external leg sloping coping range)

Available Sizes: 510mm, 535mm, 560mm, 585mm, 610mm, 635mm, 660mm, 685mm, 710mm, 735mm, 760mm, 785mm, 810mm, 835mm, 860mm, 885mm, 910mm, 935mm, 960mm, 985mm, 1010mm, 1035mm, 1060mm (23 sizes in 25mm increments)

Wall Width Range Served: Approximately 315mm to 865mm (for 100mm external leg + 75mm internal leg + 10mm returns each side)

Finish: Polyester powder coating, external grade, NOT anodised

Colour: Any RAL colour to order

Type: Closed (fully sealed end face)

Compatible System: 3mm Aluminium Sloping Coping | 100mm External Leg

Recommended Bracket: 5mm Aluminium Coping Bracket (correct specification for all 3mm coping systems)

Fabrication: Made to order - non-returnable unless faulty

Country of Manufacture: United Kingdom (Chelmsford, Essex)

How to Measure for the Correct Stopend Size

The sizing formula for the 3mm sloping coping 100mm external leg system is the same as for the 2mm 100mm system: wall width + 195mm = overall coping girth and stopend size. The difference is the wall width range this system serves. The calculation:

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

  • Add the external leg (100mm) and the internal leg (75mm) = 175mm.

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

  • Total: wall width + 195mm = stopend size. A 315mm commercial parapet wall gives 315 + 195 = 510mm, the smallest available size. A 540mm wide parapet (a substantial commercial wall) gives 540 + 195 = 735mm.

  • The size range of 510mm–1060mm confirms that this product is for wall widths of approximately 315mm–865mm. If your calculated size is below 510mm, your wall is likely domestic-spec and the 2mm sloping coping system with a smaller size range is the correct product. If the calculated size exceeds 1060mm, contact Online Metal Store Ltd to discuss bespoke options.

  • Quickest method on site: measure the overall width of an installed 3mm sloping coping length directly across the top surface from external leg tip to internal leg tip. That measurement is the stopend size.

How to Fit a 3mm Left Handed Sloping Coping Stopend

Mark bracket positions along the full parapet run before fixing anything. Fix the 5mm aluminium coping brackets at the confirmed centres, with a bracket within 150-200mm of the left run terminal. On a commercial site where wind loading calculations have been carried out, use the engineered bracket centres rather than the default 1000mm maximum. Ensure the end bracket is positioned so the stopend can seat fully over the end of the final straight length without the bracket fouling the stopend profile.

Offer the left handed stopend to the left terminal of the run. The slope of the stopend end face must align with the slope of the final 3mm sloping coping length. Confirm the fit, then apply a continuous bead of colour coded sealant around the full internal perimeter of the stopend before pressing it to its final position. On a commercial parapet with a long exposed run, the sealant bead at the stopend is the last line of defence at the run termination. A complete, uninterrupted bead is essential.

Secure the assembly using colour coded metal fasteners in the matching RAL colour through the bracket positions. Use metal fasteners rather than timber fixings on commercial substrate constructions. Apply a neat finishing bead of sealant on the external joint face. Install the right handed stopend at the right terminal of the same run in the same sequence.

Where the 3mm Left Handed Sloping Coping Stopend Is Used

Commercial Flat Roof Parapets with Sloping Coping Specification

Commercial buildings, including office developments, healthcare facilities, retail units and mixed-use schemes, where sloping coping has been specified for the parapet system require the 3mm gauge for all components, including stopends. On a commercial building with a perimeter parapet of 40 or more linear metres, the 3mm sloping coping lengths, all four corner types, left and right handed stopends, and the 5mm brackets are ordered as a complete system package from the Chelmsford manufacturer. The aluminium coping case study shows a full aluminium coping system installed on a live UK commercial project.

New-Build Housing with Insulated Cavity Parapets

On NHBC-registered new-build developments where the house type includes a parapet detail with an insulated cavity wall construction, the parapet wall width regularly falls in the 300mm–450mm range, putting the coping girth into the lower half of the 510mm–1060mm size range. Housebuilders specifying 3mm sloping coping for these house types order the full system, including left and right handed stopends, for each unit or plot on the development. The aluminium sloped coping case study demonstrates the sloping coping system deployed across multiple units on a London residential development.

Exposed and Coastal Sites

Buildings on open-aspect sites, coastal locations and elevated positions across the South East require coping systems that can resist higher wind loads than sheltered suburban settings. For sites within a few kilometres of the Essex or Kent coast, or on open farmland and hilltop positions across the Home Counties, the 3mm sloping coping system with 5mm brackets at tighter centres is the specification that delivers the service life expected on these sites. The left handed stopend in 3mm is as important as any other component in this specification: the run termination is one of the highest-risk points for wind-induced peel at an exposed site.

Replacement Coping on Existing Commercial Buildings

When replacing failed or degraded sloping coping on an existing commercial building, the replacement gauge must match or exceed the original specification. If the existing system is 3mm, the replacement must be 3mm. A 2mm replacement on a 3mm installation leaves the system under-specified at every junction between old and new components. For refurbishment projects on commercial buildings across Essex, East London and the South East, ordering the replacement coping system from the aluminium sloping coping range with the correct gauge, leg size, colour and stopend hands ensures a like-for-like or better specification.

Frequently Asked Questions

When should I use 3mm sloping coping instead of 2mm?

Use 3mm when the project is commercial rather than domestic, when the site is exposed to higher wind loads, when the parapet wall is wide enough to fall in the 510mm–1060mm coping girth range, when an NHBC or structural specification calls for 3mm, or when the building is on a coastal or exposed-aspect site. For straightforward domestic flat roof extensions with sheltered aspects and narrow parapet walls, the 2mm sloping coping system is usually the right choice. For everything else, 3mm is the safer long-term specification.

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. Every straight coping run requires one of each. The handedness is determined by the slope direction of the coping profile: the left handed stopend closes the left terminal with the slope running in the correct direction for that end. Fitting the wrong hand reverses the slope at the terminal and the joint will not close correctly.

How do I calculate the correct stopend size?

Wall width + 195mm = stopend size. That figure accounts for the 100mm external leg, 75mm internal leg and 10mm returns on each side (100 + 75 + 10 + 10 = 195). A 315mm commercial parapet wall gives 510mm, the smallest size available. A 540mm wall gives 735mm. If your calculated size falls below 510mm, the 2mm sloping coping system with its smaller size range is likely the more appropriate product. If it exceeds 1060mm, contact Online Metal Store Ltd to discuss bespoke options.

What bracket do I use with the 3mm sloping coping system?

The 5mm aluminium coping bracket is the correct specification for all 3mm coping systems, whether flat or sloping. The 5mm bracket is heavier and provides greater fixing resistance than the 4mm bracket, which is specified for the 2mm system. Do not substitute a 4mm bracket for a 5mm on a commercial or exposed-site 3mm installation. On sites where wind loading calculations have been carried out, bracket centres should be confirmed against the engineered specification. The 5mm coping bracket is available from the same range.

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. The current product page incorrectly refers to anodising in several places these are errors and are not applicable to this product. All components in the Online Metal Store Ltd 3mm sloping coping range are finished with polyester powder coating only. There is no anodising option.

Part of a Complete 3mm Sloping Coping System | 100mm External Leg

This left handed stopend is one component in the complete 3mm aluminium sloping coping system with a 100mm external leg. On a commercial project, all system components should be ordered from the same Chelmsford manufacturer to guarantee matching profiles, consistent colour across the full perimeter, and a single-source system with a clear specification. The full 3mm sloping coping system with 100mm external leg includes:

For the full sloping coping range across both 2mm and 3mm gauges, visit the Aluminium Sloping Coping collection page and the Aluminium Copings overview page. If the project calls for 2mm sloping coping, the 2mm sloping coping left handed closed stopend is the equivalent terminal piece for the lighter-gauge system.

Standards and Compliance

Aluminium sloping coping systems on flat roof parapets in the UK are specified under BS 6229:2018 - Flat Roofs with Continuously Supported Flexible Waterproof Coverings. This standard covers parapet and edge detailing for flat roofs including coping system specification and termination requirements. The 3mm gauge is consistent with the heavier-specification requirements for commercial and exposed-site coping systems referenced within this standard.

The external grade polyester powder coat finish applied to all components in the 3mm sloping coping range meets the requirements of BS EN 12206-1 - Organic Coatings on Aluminium and Aluminium Alloys. On a commercial project where the coping forms part of a contract document or long-term maintenance specification, having a documented coating standard across every component in the system, from lengths to stopends, is part of the compliance position.

For NHBC-registered new-build projects, Chapter 7.1 of the NHBC Standards sets out parapet wall and flat roof construction requirements. A 3mm aluminium sloping coping system with correctly fitted and sealed stopends at all run terminations is consistent with these requirements and supports the warranty position on new-build completions where the heavier gauge is specified.

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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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