Aluminium Termination Bar – 2500mm Length

Getting the membrane termination right is one of those details that separates a proper flat roofing job from one that comes back to haunt you. If the edge lifts, water gets behind the membrane, and within a season you have got damp tracking into the building. It is an expensive callback and a headache nobody needs.

Our aluminium termination bar takes the worry out of that detail. It clamps the membrane firmly to the upstand or wall face, giving you a clean mechanical fix that stays put. Whether you are finishing an EPDM rubber roof on a garage in Chelmsford, sealing a single ply membrane on a commercial unit in East London, or terminating felt at a parapet wall on a school in Basildon, this bar does the job properly and looks right when it is done.

Product Overview

An aluminium termination bar is a flat, pre-drilled metal strip used to secure the upper edge of a roofing membrane where it meets a vertical surface. That surface might be a brick wall, a parapet upstand, a rooflight kerb or any other vertical detail on a flat roof. The bar is screwed through the membrane and into the substrate, clamping the material in place. A bead of sealant along the top edge of the bar then completes the waterproof seal.

We supply our termination bars in 2500mm lengths, which is the standard trade size and covers most upstand runs without needing a joint. Each bar is manufactured from durable aluminium with pre-drilled fixing holes at regular centres for fast, accurate installation. You can order in mill finish or have them powder coated to any RAL colour to match the surrounding roofline. For an even cleaner finish at the membrane edge, pair this bar with our colour coded sealant in a matching RAL shade.

Online Metal Store Ltd manufactures these termination bars at our factory in Chelmsford, Essex, and dispatches across the UK. We understand flat roofing details because we produce the components that go into them every day.

Key Benefits

Reliable mechanical fix

Unlike adhesive-only terminations that can peel away in high winds or after prolonged UV exposure, a termination bar gives you a positive mechanical clamp along the full length of the membrane edge. Once it is screwed down and sealed, it is not going anywhere. That peace of mind matters, especially on exposed sites or taller buildings where wind uplift is a genuine concern.

Pre-drilled for speed on site

The fixing holes are already punched at regular centres, so there is no need to measure and drill on site. Line the bar up, drive your fixings in and move on. On a commercial job where you might be running 20 or 30 metres of termination bar across multiple upstands, that time saving adds up fast.

Powder coating in any RAL colour

Not every project can get away with a mill finish strip across the top of the upstand. On visible parapet walls, shopfronts, schools and residential extensions where the detail is on show, a powder coated termination bar in a matching RAL colour gives you a much tidier result. It is a small upgrade that makes the finished job look significantly more professional.

Built for British weather

Aluminium does not rust, and it handles everything the UK climate throws at it. Driving rain in the South West, frost cycles across the Midlands, salt-laden coastal air in Essex and Kent. The bar will not corrode, warp or degrade over time, which is exactly what you want from a component that is holding your membrane in place for the next 25 years or more.

Lightweight and easy to handle

A 2500mm length of aluminium termination bar weighs very little. You can carry several up a ladder without any difficulty, and cutting it to length on site with a hacksaw or snips takes seconds. There is no comparison to working with heavier steel alternatives, especially on a long day up on the roof.

Made in Chelmsford, delivered nationwide

We manufacture these bars at our facility on Southend Road in Chelmsford, Essex. Whether you are a roofer in Colchester, a contractor in Central London, or a builder up in Manchester, we will get the order to you quickly. Local customers in Essex are welcome to collect.

Technical Specifications

Material: Aluminium

Length: 2500mm

Width: 40mm with 10mm lip

Fixing Holes: Pre-drilled at regular centres

Finish Options: Mill finish as standard, or polyester powder coated (PPC) to any RAL colour

Compatible Membranes: EPDM rubber, single ply (TPO, PVC), built-up felt, liquid applied waterproofing

Suitable Applications: Flat roof upstands, parapet walls, rooflight kerbs, cladding terminations, wall abutments

Manufactured In: Chelmsford, Essex, United Kingdom

Custom Fabrication: Yes. Powder coated to order. Non-returnable unless faulty.

How to Install an Aluminium Termination Bar

Fitting a termination bar is straightforward, but getting the detail right matters. Here is the process:

Start by positioning the membrane up the face of the upstand or wall, ensuring it sits flat with no creases or air pockets. Place the termination bar over the membrane, aligning it horizontally along the top edge of the upstand. Fix the bar through the pre-drilled holes using appropriate screws or masonry fixings, depending on the substrate. Work along the length of the bar, tightening each fixing evenly to create consistent clamping pressure. Once the bar is secured, run a continuous bead of sealant along the top edge of the bar where it meets the wall. Our colour coded sealant in 300ml cartridges is ideal for this step, especially on powder coated bars where you want a colour-matched seal.

Make sure the sealant fills the full width of the gap between the top of the bar and the wall surface. This sealant line is your final defence against water getting behind the membrane, so do not rush it. On longer runs, butt the bars tightly together and seal the joint between them as well.

Where Aluminium Termination Bars Are Used

Flat roof upstands on domestic extensions

This is the bread and butter application. A homeowner in Brentwood or Billericay extends their kitchen with a flat roof, and the EPDM or felt membrane needs terminating where it meets the house wall. The termination bar clamps the membrane at the top of the upstand, and a cover flashing or lead apron dresses over the top. For the perimeter edge of the same roof, our aluminium roof edge drip trim finishes the detail neatly.

Parapet walls on commercial buildings

On commercial flat roofs with parapet walls, the membrane runs up the inner face of the parapet and needs securing at the top before the coping sits over it. A termination bar along the top of the membrane run provides the mechanical fix. On these jobs, pair it with an aluminium flat coping or aluminium sloping coping to complete the parapet detail from membrane to cap.

Cladding and curtain wall terminations

Where cladding panels or curtain wall systems meet a roofing membrane, a termination bar provides a clean junction between the two materials. It gives the membrane a solid fixing point and creates a straight, consistent line that the cladding detail can butt up to. Browse our full range of trims, flashings and angles for other components you might need on the same project.

Rooflight kerb and penetration details

Any penetration through a flat roof, whether it is a rooflight, a vent pipe or an access hatch, needs a proper membrane termination around its kerb. A termination bar running around each face of the kerb gives you a mechanical fix at every edge, which is far more reliable than relying on adhesive alone, especially on the exposed faces that take the brunt of the weather.

Refurbishment and overlay projects

On refurbishment jobs where a new membrane is being laid over an existing flat roof, termination bars are essential at every upstand and abutment. The bar clamps the new membrane in place without disturbing the structure underneath. For the wider refurbishment, our aluminium retention trim works alongside the termination bar to secure the membrane at the roof perimeter.

Frequently Asked Questions

What is a termination bar used for on a flat roof?

A termination bar is used to mechanically secure the upper edge of a roofing membrane where it meets a vertical surface such as a wall, parapet upstand or rooflight kerb. The bar is screwed through the membrane and into the substrate, clamping the material in place. A bead of sealant along the top edge of the bar completes the waterproof seal. It is the standard method for terminating EPDM, single ply and felt membranes on flat roofs across the UK.

How do you fix a termination bar to a wall?

Position the membrane up the wall face and hold the termination bar over it, aligned horizontally. Fix the bar through the pre-drilled holes using screws or masonry fixings appropriate for the substrate. Tighten evenly along the length of the bar to create consistent clamping pressure. Then run a continuous bead of sealant along the top edge where the bar meets the wall. The sealant is your final waterproofing line, so make sure it fills the full width of the gap.

What size termination bar do I need for EPDM?

Our termination bar is 2500mm long with a 40mm width and 10mm lip, which is the standard specification for EPDM membrane terminations on domestic and commercial flat roofs. The 2500mm length covers most upstand runs in a single piece, minimising joints. For longer runs, butt multiple bars together and seal the joint between them.

Can an aluminium termination bar be powder coated?

Yes. We offer polyester powder coating in any RAL colour. This is especially useful on visible upstands, shopfronts, schools and residential projects where a mill finish strip would look out of place. Select your RAL colour when you order and we will fabricate the bar to match.

Is a termination bar better than chasing into the wall?

In most practical situations, yes. Chasing a slot into brickwork or blockwork weakens the wall face and creates dust and debris. A surface-mounted termination bar achieves the same result without cutting into the substrate, which is quicker, cleaner and less disruptive. It is also easier to replace or re-seal in the future if maintenance is needed. Chasing is still used on some jobs where the detail demands it, but a termination bar is the preferred method for the vast majority of flat roof membrane terminations in the UK.

What sealant should I use with a termination bar?

Use a good quality polyurethane or modified silicone sealant rated for external use and compatible with the membrane type. Apply a continuous bead along the top edge of the bar where it meets the wall. On powder coated bars, a colour matched sealant gives the neatest result. We stock colour coded sealant in 300ml cartridges across the full RAL range.

Termination Bar vs Chasing vs Adhesive: Which Method Should You Use?

Aluminium termination bar (surface mounted)

The most common and practical method on UK flat roofs. Gives you a positive mechanical fix without cutting into the wall. Pre-drilled holes make installation fast. The bar protects the membrane edge from wind uplift and provides a clean line for the sealant. Works on brick, block, concrete, timber and steel substrates. Easy to inspect, re-seal or replace in the future. Available powder coated for a tidy finish on visible details.

Chasing into the wall

Involves cutting a horizontal slot into the brickwork or render, tucking the membrane into the slot and pointing over it with mortar or sealant. Gives a flush finish with no visible bar, which can look neater on certain heritage or conservation projects. However, chasing weakens the wall face, creates dust and mess, and is harder to maintain or re-do if the seal fails. It is slower and more disruptive than using a termination bar, and on many modern builds the specification calls for a surface-mounted bar anyway.

Adhesive-only termination

Relies entirely on contact adhesive or bonding tape to hold the membrane to the upstand. No mechanical fix. This can work in sheltered, low-risk situations, but it is inherently less reliable than a termination bar, especially on exposed sites or taller buildings where wind uplift is a factor. Over time, UV exposure and thermal cycling can degrade the adhesive bond. Most roofing membrane manufacturers recommend mechanical fixing at termination points for warranty compliance.

For the vast majority of flat roofing work in the UK, a surface-mounted aluminium termination bar is the right choice. It is fast to install, reliable in the long term and accepted by all major membrane manufacturers.

Standards and Compliance

Aluminium termination bars should be installed in accordance with the membrane manufacturer's guidelines and relevant British Standards. BS 6229:2018 (Flat roofs with continuously supported flexible waterproof coverings) sets out best practice for membrane termination details on flat roofs, including mechanical fixing at upstands. For new-build projects requiring NHBC warranty sign-off, the NHBC Standards Chapter 7.1 on flat roofs provides additional guidance on acceptable termination details. Getting this right is not just about workmanship. It protects the warranty, the building and the people inside it.