{"product_id":"aluminium-roof-trim-2-4m","title":"2mm Aluminium Retention Trim - 2.4m Length","description":"\u003cp dir=\"ltr\"\u003e\u003cspan\u003eThe heavier 2mm version of the aluminium retention trim, supplied in 2.4m lengths. It secures flat roof waterproofing membranes at the roof perimeter and retains growing substrate, pebble ballast or drainage layers on green and living roofs. Available in eight sizes from 50x100mm to 300x150mm, where the first dimension is the face height and the second is the base depth. Choose the face height to match the installed depth of your substrate or membrane layer. Powder coated in any RAL colour and manufactured in the UK at the Online Metal Store Ltd facility in Chelmsford. For the lighter gauge version, see the \u003c\/span\u003e\u003ca href=\"https:\/\/onlinemetalstore.co.uk\/products\/aluminium-retention-trim-2-4m\" target=\"_blank\" rel=\"noopener\"\u003e\u003cspan\u003e1.5mm aluminium retention trim\u003c\/span\u003e\u003c\/a\u003e\u003cspan\u003e.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp dir=\"ltr\"\u003e\u003cspan\u003eThe 2mm gauge is the correct specification for heavier-loaded applications: green roofs with a deeper substrate layer or pebble ballast of 150mm or more, exposed sites where wind pressure on the trim face is higher than standard, and commercial flat roofs where the specification calls for the heavier section. Like the 1.5mm version, the face has drainage slots for free water flow and the base has fixing holes for mechanical attachment or bonding straps.\u003c\/span\u003e\u003cb\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003ch2 dir=\"ltr\"\u003e\u003cspan\u003eUnderstanding the Sizes: Face Height x Base Depth\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp dir=\"ltr\"\u003e\u003cspan\u003eThe eight size options listed as two dimensions (e.g. 50x100mm, 75x100mm) can be confusing without an explanation. Here is what each figure means:\u003c\/span\u003e\u003c\/p\u003e\n\u003ch3 dir=\"ltr\"\u003e\u003cspan\u003eFirst Dimension: Face Height\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp dir=\"ltr\"\u003e\u003cspan\u003eThe vertical height of the exposed face of the trim. This is the dimension that needs to match the installed depth of the substrate, growing medium or pebble layer on a green roof, or the height of the membrane upstand on a standard flat roof. Select this dimension to match the layer depth at the perimeter. If the growing medium is 100mm deep, use a 100mm face height. If it is 150mm deep, use a 150mm face height.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch3 dir=\"ltr\"\u003e\u003cspan\u003eSecond Dimension: Base Depth\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp dir=\"ltr\"\u003e\u003cspan\u003eThe horizontal depth of the flat base that sits on the roof deck. A wider base gives a larger fixing footprint and greater stability against lateral pressure from the substrate layer. The 100mm base suits most standard applications; the 150mm base is better suited to deeper substrate loads and exposed sites where additional base area improves resistance to overturning.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch4 dir=\"ltr\"\u003e\u003cspan\u003eSize Selection Guide\u003c\/span\u003e\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli dir=\"ltr\" aria-level=\"1\"\u003e\n\u003cp dir=\"ltr\" role=\"presentation\"\u003e\u003cspan\u003e50 x 100mm: \u003c\/span\u003e\u003cspan\u003eshallow membrane retention on standard flat roofs. Smallest available face height.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli dir=\"ltr\" aria-level=\"1\"\u003e\n\u003cp dir=\"ltr\" role=\"presentation\"\u003e\u003cspan\u003e75 x 100mm: \u003c\/span\u003e\u003cspan\u003estandard green roof application with a shallow growing medium or lightweight drainage layer.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli dir=\"ltr\" aria-level=\"1\"\u003e\n\u003cp dir=\"ltr\" role=\"presentation\"\u003e\u003cspan\u003e100 x 100mm: \u003c\/span\u003e\u003cspan\u003emedium-depth green roof substrate retention. Most common commercial specification.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli dir=\"ltr\" aria-level=\"1\"\u003e\n\u003cp dir=\"ltr\" role=\"presentation\"\u003e\u003cspan\u003e120 x 100mm: \u003c\/span\u003e\u003cspan\u003egreen roofs with substrate depths up to 120mm or pebble ballast layers of similar depth.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli dir=\"ltr\" aria-level=\"1\"\u003e\n\u003cp dir=\"ltr\" role=\"presentation\"\u003e\u003cspan\u003e150 x 150mm: \u003c\/span\u003e\u003cspan\u003edeeper substrate applications. Wider base for additional stability.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli dir=\"ltr\" aria-level=\"1\"\u003e\n\u003cp dir=\"ltr\" role=\"presentation\"\u003e\u003cspan\u003e200 x 150mm: \u003c\/span\u003e\u003cspan\u003eintensive green roofs with deeper growing media and heavier substrate loads.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli dir=\"ltr\" aria-level=\"1\"\u003e\n\u003cp dir=\"ltr\" role=\"presentation\"\u003e\u003cspan\u003e250 x 150mm: \u003c\/span\u003e\u003cspan\u003edeep substrate retention. Used on intensive green roofs with planted areas.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli dir=\"ltr\" aria-level=\"1\"\u003e\n\u003cp dir=\"ltr\" role=\"presentation\"\u003e\u003cspan\u003e300 x 150mm: \u003c\/span\u003e\u003cspan\u003emaximum standard face height. For the deepest substrate layers and planted roof applications.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2 dir=\"ltr\"\u003e\u003cspan\u003e1.5mm or 2mm: Which Gauge Do You Need?\u003c\/span\u003e\u003c\/h2\u003e\n\u003ch3 dir=\"ltr\"\u003e\u003cspan\u003eUse 1.5mm When\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp dir=\"ltr\"\u003e\u003cspan\u003eThe application is a standard domestic or light commercial flat roof with a shallow membrane retention requirement, or a green roof with a growing medium depth up to approximately 100mm in a sheltered position. The \u003c\/span\u003e\u003ca href=\"https:\/\/onlinemetalstore.co.uk\/products\/aluminium-retention-trim-2-4m\" target=\"_blank\" rel=\"noopener\"\u003e\u003cspan\u003e1.5mm retention trim\u003c\/span\u003e\u003c\/a\u003e\u003cspan\u003e covers the majority of domestic flat roof extension and light commercial green roof applications at a lower material cost.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch3 dir=\"ltr\"\u003e\u003cspan\u003eUse 2mm When\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp dir=\"ltr\"\u003e\u003cspan\u003eThe application involves a deeper or heavier substrate load (150mm or more), an exposed site where wind pressure on the trim face is above the standard sheltered baseline, a commercial project where the specification calls for 2mm gauge, or an intensive planted green roof where the substrate and loaded planting exerts meaningful lateral pressure on the trim face. The 2mm section provides greater rigidity and resistance to deflection under these conditions.\u003c\/span\u003e\u003cb\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003ch4 dir=\"ltr\"\u003e\u003cspan\u003eKey Benefits\u003c\/span\u003e\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli dir=\"ltr\" aria-level=\"1\"\u003e\n\u003cp dir=\"ltr\" role=\"presentation\"\u003e\u003cspan\u003eHeavier 2mm gauge for demanding applications: \u003c\/span\u003e\u003cspan\u003egreater rigidity than the 1.5mm version under lateral substrate pressure, deeper growing media loads, and higher wind exposure.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli dir=\"ltr\" aria-level=\"1\"\u003e\n\u003cp dir=\"ltr\" role=\"presentation\"\u003e\u003cspan\u003eDrainage slots in the face: \u003c\/span\u003e\u003cspan\u003eallows free water drainage through the trim face while retaining substrate, pebbles or ballast. Prevents water damming at the trim that could back up under the waterproofing layer.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli dir=\"ltr\" aria-level=\"1\"\u003e\n\u003cp dir=\"ltr\" role=\"presentation\"\u003e\u003cspan\u003e8 sizes covering 50mm to 300mm face heights: \u003c\/span\u003e\u003cspan\u003eface height matches the installed substrate or membrane depth at the perimeter. Base depth of 100mm or 150mm gives the correct fixing footprint for the load.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli dir=\"ltr\" aria-level=\"1\"\u003e\n\u003cp dir=\"ltr\" role=\"presentation\"\u003e\u003cspan\u003ePre-drilled fixing holes in the base: \u003c\/span\u003e\u003cspan\u003efor mechanical fixing with corrosion-resistant screws or bolts, or for bonding straps where adhesive bonding is specified.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli dir=\"ltr\" aria-level=\"1\"\u003e\n\u003cp dir=\"ltr\" role=\"presentation\"\u003e\u003cspan\u003eAny RAL colour powder coated: \u003c\/span\u003e\u003cspan\u003ematches fascia, coping, guttering and other external aluminium components on the same building.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli dir=\"ltr\" aria-level=\"1\"\u003e\n\u003cp dir=\"ltr\" role=\"presentation\"\u003e\u003cspan\u003e2.4m lengths with joiner connector: \u003c\/span\u003e\u003cspan\u003ereduces joint count on longer runs. Joiner connectors allow straight joints and can be bent to form internal and external angles at corners.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli dir=\"ltr\" aria-level=\"1\"\u003e\n\u003cp dir=\"ltr\" role=\"presentation\"\u003e\u003cspan\u003eUK manufactured in Chelmsford: \u003c\/span\u003e\u003cspan\u003econsistent quality and fast lead times for projects across Essex, the South East and the wider UK.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 dir=\"ltr\"\u003e\u003cspan\u003eTechnical Specifications\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp dir=\"ltr\"\u003e\u003cspan\u003e\u003cstrong\u003eMaterial:\u003c\/strong\u003e \u003c\/span\u003e\u003cspan\u003e2mm grade aluminium\u003c\/span\u003e\u003c\/p\u003e\n\u003cp dir=\"ltr\"\u003e\u003cstrong\u003eLength: \u003c\/strong\u003e\u003cspan\u003e2.4m (2400mm) per section\u003c\/span\u003e\u003c\/p\u003e\n\u003cp dir=\"ltr\"\u003e\u003cstrong\u003eSizes Available: \u003c\/strong\u003e\u003cspan\u003e50x100mm, 75x100mm, 100x100mm, 120x100mm, 150x150mm, 200x150mm, 250x150mm, 300x150mm\u003c\/span\u003e\u003c\/p\u003e\n\u003cp dir=\"ltr\"\u003e\u003cstrong\u003eSize Notation: \u003c\/strong\u003e\u003cspan\u003eFace height x Base depth\u003c\/span\u003e\u003c\/p\u003e\n\u003cp dir=\"ltr\"\u003e\u003cspan\u003e\u003cstrong\u003eDrainage Slots:\u003c\/strong\u003e \u003c\/span\u003e\u003cspan\u003eLaser-cut slots in face for free water drainage while retaining substrate\u003c\/span\u003e\u003c\/p\u003e\n\u003cp dir=\"ltr\"\u003e\u003cstrong\u003eFixing Holes: \u003c\/strong\u003e\u003cspan\u003ePre-drilled holes in base for mechanical fixing or bonding straps\u003c\/span\u003e\u003c\/p\u003e\n\u003cp dir=\"ltr\"\u003e\u003cstrong\u003eJoiner Connector: \u003c\/strong\u003e\u003cspan\u003eIncluded with each 2.4m length for straight joints and angle formation\u003c\/span\u003e\u003c\/p\u003e\n\u003cp dir=\"ltr\"\u003e\u003cstrong\u003eFinish: \u003c\/strong\u003e\u003cspan\u003ePolyester powder coating, external grade, any RAL colour\u003c\/span\u003e\u003c\/p\u003e\n\u003cp dir=\"ltr\"\u003e\u003cstrong\u003eFire Rating: \u003c\/strong\u003e\u003cspan\u003eA2-s1,d0 (non-combustible)\u003c\/span\u003e\u003c\/p\u003e\n\u003cp dir=\"ltr\"\u003e\u003cstrong\u003eApplications: \u003c\/strong\u003e\u003cspan\u003eGreen roof substrate retention, flat roof membrane retention, pebble ballast containment, intensive planted roofs\u003c\/span\u003e\u003c\/p\u003e\n\u003cp dir=\"ltr\"\u003e\u003cspan\u003e\u003cstrong\u003eCompatible Systems:\u003c\/strong\u003e \u003c\/span\u003e\u003cspan\u003eSingle ply (TPO, PVC, EPDM), built-up felt, liquid-applied waterproofing\u003c\/span\u003e\u003c\/p\u003e\n\u003cp dir=\"ltr\"\u003e\u003cstrong\u003ePrice: \u003c\/strong\u003e\u003cspan\u003e£18.56 ex VAT per 2.4m length (£22.27 inc VAT)\u003c\/span\u003e\u003c\/p\u003e\n\u003cp dir=\"ltr\"\u003e\u003cstrong\u003eFabrication: \u003c\/strong\u003e\u003cspan\u003eMade in the UK, Chelmsford Essex\u003c\/span\u003e\u003cb\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003ch2 dir=\"ltr\"\u003e\u003cspan\u003eHow Many Lengths Do You Need?\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp dir=\"ltr\"\u003e\u003cspan\u003eMeasure the total linear metres where retention trim is needed. Divide by 2.4m and round up to the nearest whole number. Allow for a small expansion gap (approximately 2mm) between lengths at each joint.\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli dir=\"ltr\" aria-level=\"1\"\u003e\n\u003cp dir=\"ltr\" role=\"presentation\"\u003e\u003cspan\u003e12m perimeter: 12 \/ 2.4 = 5 sections exactly.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli dir=\"ltr\" aria-level=\"1\"\u003e\n\u003cp dir=\"ltr\" role=\"presentation\"\u003e\u003cspan\u003e15m perimeter: 15 \/ 2.4 = 6.25 -- order 7 sections.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli dir=\"ltr\" aria-level=\"1\"\u003e\n\u003cp dir=\"ltr\" role=\"presentation\"\u003e\u003cspan\u003e24m perimeter: 24 \/ 2.4 = 10 sections exactly.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli dir=\"ltr\" aria-level=\"1\"\u003e\n\u003cp dir=\"ltr\" role=\"presentation\"\u003e\u003cspan\u003eOn complex roof plans with internal and external angles, the joiner connectors handle direction changes without cutting, so no additional allowance is needed for corners.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 dir=\"ltr\"\u003e\u003cspan\u003eInstallation Overview\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp dir=\"ltr\"\u003e\u003cspan\u003eFix the retention trim to the flat roof perimeter before the membrane or substrate layer is installed. The base of the trim sits flat on the roof deck surface. Fix through the pre-drilled holes in the base using corrosion-resistant fixings at the centres specified by the waterproofing system manufacturer, or bond the base to the deck surface using a compatible adhesive where mechanical fixing is not appropriate for the deck construction.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp dir=\"ltr\"\u003e\u003cspan\u003eJoin adjacent lengths using the included connector. Slide the connector into the back of the trim profile at the joint position and leave a 2mm expansion gap between the section ends. For direction changes at corners, bend the connector by hand to the required angle: connectors can form both internal and external angles without separate corner pieces, which simplifies installation on complex roof plans.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp dir=\"ltr\"\u003e\u003cspan\u003eOnce all trim sections are fixed and joined, install the membrane or substrate layer. The top of the trim face should align with the finished surface level of the substrate or membrane upstand, containing the layer completely at the perimeter. For a complete flat roof edge detail at the exposed outer perimeter, use the \u003c\/span\u003e\u003ca href=\"https:\/\/onlinemetalstore.co.uk\/products\/aluminium-roof-edge-drip-trim-3m\" target=\"_blank\" rel=\"noopener\"\u003e\u003cspan\u003ealuminium drip trim\u003c\/span\u003e\u003c\/a\u003e\u003cspan\u003e at the drip edge alongside this retention trim at the upstand.\u003c\/span\u003e\u003cb\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003ch2 dir=\"ltr\"\u003e\u003cspan\u003eWhere the 2mm Retention Trim Is Used\u003c\/span\u003e\u003c\/h2\u003e\n\u003ch3 dir=\"ltr\"\u003e\u003cspan\u003eExtensive and Intensive Green Roofs\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp dir=\"ltr\"\u003e\u003cspan\u003eOn green and living roofs, the retention trim contains the growing medium, substrate, or drainage layer at the roof edge while allowing water to drain freely through the slotted face. The 2mm gauge is the correct specification for intensive green roofs with a deeper planted substrate of 150mm or more, where the lateral pressure on the trim face from the loaded growing medium is higher than on a shallow sedum roof. For very deep planted roof applications with substrate over 250mm, specify the 300x150mm size and consult the waterproofing system designer for structural advice. For green roof maintenance access, the \u003c\/span\u003e\u003ca href=\"https:\/\/onlinemetalstore.co.uk\/products\/aluminium-inspection-chamber-300\" target=\"_blank\" rel=\"noopener\"\u003e\u003cspan\u003ealuminium inspection chambers\u003c\/span\u003e\u003c\/a\u003e\u003cspan\u003e complement the retention trim system.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch3 dir=\"ltr\"\u003e\u003cspan\u003eExposed Site Flat Roofs\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp dir=\"ltr\"\u003e\u003cspan\u003eOn flat roofs on buildings in exposed coastal, elevated or high wind-speed locations, the 2mm gauge provides greater resistance to wind-induced movement at the trim face. On a sheltered domestic flat roof in a suburban setting, the 1.5mm trim is adequate. On a commercial building near the Essex coast or on an open aspect site where wind loading has been calculated as higher than the standard sheltered baseline, the 2mm trim is the correct specification.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch3 dir=\"ltr\"\u003e\u003cspan\u003eCommercial Flat Roofs\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp dir=\"ltr\"\u003e\u003cspan\u003eThe 2mm section is the standard commercial specification for flat roof retention trims on office, retail, healthcare and light industrial buildings where a heavier-gauge edge detail is called for by the waterproofing contractor or the project specification. On commercial projects where the retention trim is ordered alongside parapet \u003c\/span\u003e\u003ca href=\"https:\/\/onlinemetalstore.co.uk\/pages\/aluminium-copings\" target=\"_blank\" rel=\"noopener\"\u003e\u003cspan\u003ealuminium coping\u003c\/span\u003e\u003c\/a\u003e\u003cspan\u003e, fascia boards and guttering, specifying all external aluminium components from the same Chelmsford manufacturer gives colour-matched components in the same RAL across the full building envelope.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch3 dir=\"ltr\"\u003e\u003cspan\u003eBallasted Single Ply Roof Systems\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp dir=\"ltr\"\u003e\u003cspan\u003eOn warm roof constructions with a loose-laid single ply membrane protected by a pebble ballast layer, the retention trim holds the ballast at the roof perimeter. The drainage slots prevent water from damming against the trim inside the ballast layer, and the wider base size options (150mm base) give the trim greater resistance to overturning under the weight and lateral pressure of a pebble ballast layer.\u003c\/span\u003e\u003cb\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003ch2 dir=\"ltr\"\u003e\u003cspan\u003eWhy Aluminium for Flat Roof Edge Retention\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp dir=\"ltr\"\u003e\u003cspan\u003ePlastic and uPVC retention trims are widely available at lower initial cost, but they have a shorter practical service life on exposed flat roofs. UV degradation causes plastic to yellow and become brittle, particularly at low temperatures when the material is most likely to crack if a load is applied. On a green roof where the trim is permanently loaded by substrate and periodically impacted by maintenance work and foot traffic, a trim that becomes brittle within 10 to 15 years is not fit for a flat roof expected to last 25 years or more.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp dir=\"ltr\"\u003e\u003cspan\u003eThe 2mm aluminium retention trim carries a fire classification of A2-s1,d0. It is non-combustible and meets the current Building Regulations requirements for external products on residential buildings over 11 metres and on commercial buildings where non-combustible external materials are specified. Plastic trims do not meet this classification and cannot be used in these positions.\u003c\/span\u003e\u003cb\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003ch2 dir=\"ltr\"\u003e\u003cspan\u003eWhy Choose Online Metal Store Ltd\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp dir=\"ltr\"\u003e\u003cspan\u003eAll our aluminium retention trims are manufactured at the Chelmsford facility and powder coated in any RAL colour as a standard offering. For projects combining green roof retention trims with parapet coping, fascia boards, rainwater goods and flat roof accessories, ordering everything from the same source gives colour consistency and a single supplier contact for the full external aluminium specification. Contact our team at \u003c\/span\u003e\u003cspan\u003esales@onlinemetalstore.co.uk\u003c\/span\u003e\u003cspan\u003e or call +44 7907 239290, Monday to Saturday 6:30am to 4:30pm, to discuss face height selection, confirm quantities, or get a quote for a complete flat roof edge package.\u003c\/span\u003e\u003cb\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003ch4 dir=\"ltr\"\u003e\u003cspan\u003eRelated Products\u003c\/span\u003e\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli dir=\"ltr\" aria-level=\"1\"\u003e\n\u003cp dir=\"ltr\" role=\"presentation\"\u003e\u003ca href=\"https:\/\/onlinemetalstore.co.uk\/products\/aluminium-retention-trim-2-4m\" target=\"_blank\" rel=\"noopener\"\u003e\u003cspan\u003e1.5mm Aluminium Retention Trim – 2.4m Length\u003c\/span\u003e\u003c\/a\u003e\u003cspan\u003e -- the lighter gauge version for standard domestic flat roofs and shallow green roofs\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli dir=\"ltr\" aria-level=\"1\"\u003e\n\u003cp dir=\"ltr\" role=\"presentation\"\u003e\u003ca href=\"https:\/\/onlinemetalstore.co.uk\/products\/aluminium-roof-edge-drip-trim-3m\" target=\"_blank\" rel=\"noopener\"\u003e\u003cspan\u003e1.5mm Aluminium Roof Edge Drip Trim – 3m Length\u003c\/span\u003e\u003c\/a\u003e\u003cspan\u003e -- the companion drip trim for the exposed outer edge of the flat roof\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli dir=\"ltr\" aria-level=\"1\"\u003e\n\u003cp dir=\"ltr\" role=\"presentation\"\u003e\u003ca href=\"https:\/\/onlinemetalstore.co.uk\/products\/aluminium-inspection-chamber-300\" target=\"_blank\" rel=\"noopener\"\u003e\u003cspan\u003eAluminium Inspection Chamber 300mm x 300mm (Deck Version)\u003c\/span\u003e\u003c\/a\u003e\u003cspan\u003e -- maintenance access point for green roof systems\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli dir=\"ltr\" aria-level=\"1\"\u003e\n\u003cp dir=\"ltr\" role=\"presentation\"\u003e\u003ca href=\"https:\/\/onlinemetalstore.co.uk\/products\/aluminium-parapet-inspection-chamb\" target=\"_blank\" rel=\"noopener\"\u003e\u003cspan\u003eAluminium Inspection Chamber 300mm x 300mm (Parapet Version)\u003c\/span\u003e\u003c\/a\u003e\u003cspan\u003e -- parapet-mounted access for living roof systems\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli dir=\"ltr\" aria-level=\"1\"\u003e\n\u003cp dir=\"ltr\" role=\"presentation\"\u003e\u003ca href=\"https:\/\/onlinemetalstore.co.uk\/products\/aluminium-inspection-chamber-450x\" target=\"_blank\" rel=\"noopener\"\u003e\u003cspan\u003eAluminium Inspection Chamber 450mm x 450mm (Deck Version)\u003c\/span\u003e\u003c\/a\u003e\u003cspan\u003e -- larger access chamber for extensive green roofs\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli dir=\"ltr\" aria-level=\"1\"\u003e\n\u003cp dir=\"ltr\" role=\"presentation\"\u003e\u003ca href=\"https:\/\/onlinemetalstore.co.uk\/pages\/aluminium-copings\" target=\"_blank\" rel=\"noopener\"\u003e\u003cspan\u003eAluminium Copings range\u003c\/span\u003e\u003c\/a\u003e\u003cspan\u003e -- for the parapet wall coping that sits above the flat roof edge detail\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli dir=\"ltr\" aria-level=\"1\"\u003e\n\u003cp dir=\"ltr\" role=\"presentation\"\u003e\u003ca href=\"https:\/\/onlinemetalstore.co.uk\/products\/colour-coded-sealant-300ml\" target=\"_blank\" rel=\"noopener\"\u003e\u003cspan\u003eColour Coded Sealant 300ml\u003c\/span\u003e\u003c\/a\u003e\u003cspan\u003e -- for additional weathersealing at trim joints where required\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2 dir=\"ltr\"\u003e\u003cspan\u003eFrequently Asked Questions\u003c\/span\u003e\u003c\/h2\u003e\n\u003ch4 dir=\"ltr\"\u003e\u003cspan\u003eWhat do the two dimensions in each size mean, e.g. 50x100mm?\u003c\/span\u003e\u003c\/h4\u003e\n\u003cp dir=\"ltr\"\u003e\u003cspan\u003eThe first figure is the face height: the vertical dimension of the exposed trim face that must match the depth of your substrate, growing medium or membrane upstand. The second figure is the base depth: the horizontal dimension of the flat base that sits on the roof deck. A deeper base gives a larger fixing footprint and better resistance to lateral pressure from a loaded substrate layer. For a 100mm deep growing medium, select a 100x100mm or 120x100mm size. For a 200mm deep planted substrate, select the 200x150mm size.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch4 dir=\"ltr\"\u003e\u003cspan\u003eWhen should I use 2mm rather than 1.5mm?\u003c\/span\u003e\u003c\/h4\u003e\n\u003cp dir=\"ltr\"\u003e\u003cspan\u003eUse 2mm when the substrate layer is deep (150mm or more), when the site is exposed or the specification calls for a heavier gauge, when the application is an intensive planted green roof with a loaded growing medium, or when the project is commercial and a 2mm section is specified. For standard domestic flat roofs and shallow sedum green roofs with a growing medium up to 100mm, the \u003c\/span\u003e\u003ca href=\"https:\/\/onlinemetalstore.co.uk\/products\/aluminium-retention-trim-2-4m\" target=\"_blank\" rel=\"noopener\"\u003e\u003cspan\u003e1.5mm retention trim\u003c\/span\u003e\u003c\/a\u003e\u003cspan\u003e is normally adequate.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch4 dir=\"ltr\"\u003e\u003cspan\u003eHow do I handle corners without cutting the trim?\u003c\/span\u003e\u003c\/h4\u003e\n\u003cp dir=\"ltr\"\u003e\u003cspan\u003eThe joiner connector included with each length can be bent by hand to form both internal and external angles. Slide the connector into the back of the trim profile at the corner position and bend it to the required angle. This creates a neat, continuous trim around the corner without requiring the trim face to be mitred on site. On complex roof plans with multiple direction changes, the flexible connectors significantly simplify the installation.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch4 dir=\"ltr\"\u003e\u003cspan\u003eIs the 2mm retention trim suitable for ballasted single ply roofs?\u003c\/span\u003e\u003c\/h4\u003e\n\u003cp dir=\"ltr\"\u003e\u003cspan\u003eYes. The trim retains the pebble ballast layer at the roof perimeter and the slotted face allows water to drain freely from the ballast layer. For ballasted roofs, the 150x150mm or larger sizes are generally recommended as the wider base provides better resistance to overturning under the weight and lateral movement of a pebble ballast layer. Check the base fixing specification with the waterproofing system manufacturer.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch4 dir=\"ltr\"\u003e\u003cspan\u003eCan I powder coat the trim to match my coping?\u003c\/span\u003e\u003c\/h4\u003e\n\u003cp dir=\"ltr\"\u003e\u003cspan\u003eYes. Specify your RAL colour at order and the trim is powder coated in the same external grade polyester finish as all other OMS aluminium products. If you are ordering this trim alongside coping, fascia boards, drip trims and rainwater goods from Online Metal Store Ltd in the same RAL, ordering everything together means the components go through the same coating batch and arrive colour-matched.\u003c\/span\u003e\u003cb\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003ch2 dir=\"ltr\"\u003e\u003cspan\u003eReady to Order?\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp dir=\"ltr\"\u003e\u003cspan\u003eSelect your face height and base depth from the size dropdown, choose your RAL colour, and add to basket. For face height advice, substrate depth confirmation, or a quote for the full flat roof edge package including drip trims, retention trims and accessories, contact our team at \u003c\/span\u003e\u003cspan\u003esales@onlinemetalstore.co.uk\u003c\/span\u003e\u003cspan\u003e or call +44 7907 239290, Monday to Saturday 6:30am to 4:30pm.\u003c\/span\u003e\u003cb\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp dir=\"ltr\"\u003e\u003cstrong\u003eCustom Fabricated Item: \u003c\/strong\u003e\u003cspan\u003eMade to order at our Chelmsford facility. Confirm face height before ordering. Non-returnable unless faulty. See our \u003c\/span\u003e\u003ca href=\"https:\/\/onlinemetalstore.co.uk\/pages\/returns-policy\" target=\"_blank\" rel=\"noopener\"\u003e\u003cspan\u003eRefund and Returns Policy\u003c\/span\u003e\u003c\/a\u003e\u003cspan\u003e for full details.\u003c\/span\u003e\u003c\/p\u003e","brand":"Online Metal Store Ltd","offers":[{"title":"50mm x 100mm","offer_id":42314535370836,"sku":"ART-20-50","price":18.56,"currency_code":"GBP","in_stock":true},{"title":"75mm x 100mm","offer_id":42314535403604,"sku":"ART-20-75","price":20.94,"currency_code":"GBP","in_stock":true},{"title":"100mm x 100mm","offer_id":42314535436372,"sku":"ART-20-100","price":24.08,"currency_code":"GBP","in_stock":true},{"title":"120mm x 100mm","offer_id":42314535469140,"sku":"ART-20-120","price":28.48,"currency_code":"GBP","in_stock":true},{"title":"150mm x 150mm","offer_id":42314535501908,"sku":"ART-20-150","price":35.1,"currency_code":"GBP","in_stock":true},{"title":"200mm x 150mm","offer_id":42314535534676,"sku":"ART-20-200","price":46.16,"currency_code":"GBP","in_stock":true},{"title":"250mm x 150mm","offer_id":42314535567444,"sku":"ART-20-250","price":57.22,"currency_code":"GBP","in_stock":true},{"title":"300mm x 150mm","offer_id":42314535600212,"sku":"ART-20-300","price":68.28,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0647\/1588\/2580\/files\/aluminium-green-roof-edge-2-4m_eb7a9d7c-d049-48a7-b818-23acbe3ac744.png?v=1774517103","url":"https:\/\/onlinemetalstore.co.uk\/products\/aluminium-roof-trim-2-4m","provider":"Online Metal Store Ltd","version":"1.0","type":"link"}