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Standing seam has been used as a roofing solution to provide an aesthetically pleasing appearance, combined with an exceptional performance for weathertightness, and has been used extensively for a variety of applications throughout the public and private sectors.

The Cladco Standing Seam cladding system can be supplied in Aluminium, either plain or coloured finish, as well as in pre-coated steel. Whichever product is chosen, the system will perform in almost any environment.

Combined with other quality products from the Cladco range, the standing seam sheets can be incorporated into a fully warrantied roofing system. Details of warranties are shown later in the brochure.

Specifying the correct gauge of material will ensure that the roofing product will perform to the required standard. Care must be taken to ensure that the relevant sections of BS6399 and BS5950 are fully understood with respect to the loadings applied. Use of the correct fixings to secure the halters to the support structure.

The Cladco Standing Seam profile is 400mm wide and 65mm deep, with 2 mini-ribs in the pan, to provide rigidity of the section.

Features & benefits

The profile can be supplied in lengths up to 18m, delivered to site on articulated vehicles. It is the customer’s responsibility to ensure that adequate access is available for vehicles of this length, and to provide suitable off-loading equipment. When off-loading long sheets (in excess of 8m), a lifting spreader beam will be required.

The roof cladding system requires a suitable liner panel, capable of supporting a person’s weight (ie non-fragile, walkable liner), a bar and bracket spacer system, Insulation to the required thickness to achieve a designated ‘U’ value, and aluminium halters. Stainless steel fixings are to be used throughout. Longer lengths are available by agreement.

All of these elements are supplied by Cladco, and by sourcing all products for the roofing system from Cladco, a full system warranty is provided, subject to registration of the project with Cladco.

Why Proseam

  • Aesthetically pleasing aluminium finish, in stucco embossed or plain, or variety of other metals
  • Variety of cavity depths to accommodate range of U values
  • No penetrations though the weather face of the sheet
  • Full range of accessories to complement the Standing Seam roof sheet
  • Product and system warranties available
  • Outstanding resistance to wind uplift
  • CE mark for Aluminium and Steel options
  • Can be used in roofing and walling applications
  • May be either a convex or concave curved, or both in a wave-form configuration
  • Can be used on roof pitches as low as 1.5 degrees (note that deflection may cause pitches lower than 1.5 degrees)
  • Seamed joint allows sheets to expand and contract without affecting the performance of the system

Halters Centres and Curving

Proseam standing seam is attached to the support structure through aluminium halters, which are fixed at pre-determined centres, using stainless steel fixings. Halters are fixed at each purlin position, and at 400mm centres along the roof. It is important that the halters are
fixed tier by tier, as the Proseam sheets are laid. This will avoid errors in spacing, leading to distortion of the standing seam sheet.

For curved roofs, the spacing of halters will vary, depending on the radius of the curve. Proseam standing seam sheets can be naturally curved down to a radius of approx 60
metres, without excessive distortion of the pan of the sheet. Tighter radii can be achieved, but the pan of the sheet will exhibit rippling, which may be acceptable.

Proseam standing seam sheets can be ‘crimp’ curved to achieve a tighter radius. Details may be obtained from our Sales Team.


Stucco embossed or plain mill finish aluminium
3000 series aluminium is used to produce the Cladco Standing Seam sheet, 0.9mm nominal thickness.
The aluminium may be plain, self colour, or may have a PVF2 or Polyester coloured finish applied. Our Sales Department will
advise on what colours and finishes are available.

200 microns plastisol coated steel
0.7mm nominal thickness galvanised steel substrate (G275 galvanised coating) with 200 micron plastisol coating.
Other coatings on steel substrates are also available, such as PVF2 and Polyester, subject to minimum quantities. Our Sales
Department will advise on availability.



Required to crimp the initial section of the Proseam sheet, providing a start for the Zipping Machine.

Zipping Machine

Powered machine to zip up the Proseam sheets – leased on a daily/weekly rental.

Eaves Turn-Down Tool

Turns the pan of the Proseam sheet down, to prevent water from travelling under of the sheet

Ridge Turn-Up Tool

Turns the pan of the Proseam sheet up to prevent water being blown into the building.


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Fixed at every purlin

Thermal Block (15mm thick)

Clips to underside of Halter, to provide a thermal break

Verge Channel (3000mm length)

Placed over the Proseam roll at the verge

Verge Clip (100mm wide)

Hooked over the verge channel and fixed into the halter

One-piece verge channel/ support (3000mm length)

Alternative section to restrain the verge of the Proseam sheet, and to provide a support for the verge flashing

Ridge zed support (3000mm length)

Provides support for the ridge flashing

Eaves Drip Angle (3000mm length)

To create a drip into the gutter at the eaves

Eaves Filler

Placed under the Proseam sheet

Ridge Filler

Placed over the Proseam sheet at the ridge

Ridge Filler Shroud

Covers the ridge filler

Liner Filler

Placed below the liner


Fixing Proseam Sheets

When fixing Proseam standing seam sheets, it is essential that a fixed end is identified, and the roof verge is perpendicular to the eaves line. Any out of square at this stage, will result in an uneven eaves line, or ‘sawtoothing’. Once the first sheet has been positioned, and secured to the verge halter by a verge clip (please refer to Cladco’s fixing instructions for details), the next sheet can then be fixed, by overlapping it onto the first sheet, and onto the next row of halters at the leading edge. Once the sheet has been checked for square and the overlap is fully engaged, the seam can be closed, securing it to the halters. The seam is secured by firstly clamping the eaves end using the hand crimper. The motorised seaming tool is then used to fully seal the seam along the remaining sheet length.

The roof can then proceed in a similar manner. Cladco would advise that the roof length is checked and the Proseam standing seam sheets are positioned such that the dimension from the verge cleader rail to the first line of halters, is approximately the same at both ends. This will give a more pleasing appearance overall. Care must be taken to ensure that the correct halter spacing is used in the calculation, especially for curved roofs.

Halter Alignment

Mis-alignment of halters can cause visible sheet deflection or distortion. It may also cause the Proseam seam to not fully engage, leading to detachment under wind loading.

Thermal Expansion

Proseam sheet seam allow for thermal expansion, as there is no positive fixing of the sheet to the halter. However, it is necessary to create a fixed point, by inserting an aluminium blind rivet through the underlapping seam into the head of the halter, at the upper end of the sheet (under the apex flashing).

For sheets in excess of 12m long, fixed points should be created by inserting 2 No fixings through the Proseam upstaged, into the halter. Care must be taken to ensure that these fixings are positioned such that they do not affect the operation of the zipping tool.

Fixing Instructions

All screws to be bi-metallic stainless fixings. The liner panel is to be Cladco 32/1000 x 0.7mm thick, which will then act as a working platform (Detail 1). If the liner is to be considered as a Vapour Control Layer (low humidity situations), side laps are to be sealed using 50 x 1 polyband tape, and end laps sealed with 2 rows of 6 x 5 sealant, positioned either side of the of the fixing. It is important to ensure that the perimeter details create an airtight junction. When a separate VCL is specified, laps and perimeters are to be sealed, to ensure its full effectiveness.

The liner panel is to be fixed in every trough at sheet ends and at sheet laps, and in alternate
troughs elsewhere.

It is important to calculate the set out of the halters, prior to fixing the first line. Ideally, the distance from the verge to the first line of halters should be the same at both ends of the building. Halters are spaced at 400mm, where the Proseam sheet is not curved, so a simple calculation can be carried out, taking the length of the building and then calculating how many spaces of 400mm fit into it. The remaining dimension is then to be divided by 2, and this will then be the dimension from the verge to the first line of halters.

When fixing the first line of halters, ensure that they are in line using a string line, or other straight edge, as if they vary too much, the Proseam sheet will not properly engage onto the head of the halter ((Detail 2). Secondly, ensure that the halters are square to the purlins. Failure to do this will cause the the sheet ends to be stepped (saw-tooth).

When fixing the halters, it is essential that they are correctly orientated – the groove in the head of the halter should be facing the direction of lay (ie facing away from the starting end of the building).

It is not recommended to fix halters to the entire roof prior to fixing any sheets. Set out a maximum of 6 lines of halters, so that any mis-alignment can be corrected as work proceeds.

Once the first line of halters has been fixed, mark the top flange of the spacer bar 400mm away from the centre of the first halter. Using a string line, or similar, fix the second line of
halters. The first Proseam sheet can now be laid, rotating it onto the first line of halters, and bringing it down onto the second line (Detail 3).

Once the first sheet has been fixed, the verge is to be secured – see detail 5 or 6.

Proceed along the roof by laying a line of halters and then fixing a Proseam sheet. Once the second sheet has been laid, the first seam can be secured, by clamping the ends of the sheets onto the halters, using the hand crimping tool.

When the sheet ends have been secured, the Zipping Machine can be positioned on the seam, and the seam clamped to the entire length of the sheet. Zipping of the sheet seams can be carried out from either end of the sheets.

25 year warranty

This applies to the performance of the aluminium standing seam roofing system, provided all elements are supplied by Cladco. Should any element of the roof construction be supplied by any other party, then the warranty will apply to the standing seam sheet only.

This warranty applies to any roof pitch down to 1.5 degrees, and any orientation. Please note that defection of the structure could create slopes of less than 1.5 degrees, and lead to ponding.

This warranty will not cover such situations.


This Warranty must be registered with Cladco at the time of ordering materials. Cladco will issue a unique warranty number to the building owner, or to the contractor to pass on to the building owner.

The Warranty is transferable to any subsequent building owner.

Any claim under this warranty will only be accepted if the unique warranty number is advised.

Cladco recommend that the roof is inspected at maximum intervals of one year, to ensure that no debris or other harmful items have been deposited on the roof. Annual inspection reports should form part of the Maintenance Manual for the building, and proof of regular inspection will be required to validate any claim under this Warranty.

Cladco must be informed of any issue in respect of this Warranty, within 30 days of any defect or problem being discovered.


This Warranty applies to the performance of the standing seam sheet or the roofing system only. It does not cover loss of gloss, or fading of any coloured finish.

Cladco’s obligation under the terms of this Warranty is limited exclusively to the cost of labour, materials and access equipment, to carry out any repairs or replacement. Any other direct, indirect or consequential losses are specifically excluded.

This Warranty applies only to the materials and products supplied by Cladco, and only then, if used in accordance with Cladco’s instructions and published details.

This Warranty is subject to English Law.

All goods must be paid for, in full, prior to the issue of the Warranty.


Damage caused by fire, lightning, flood, explosion, abnormal winds, earthquake, acts of war or riots, civil commotion, radiation, falling objects, vandalism and other extraneous causes.

Damage caused by misuse of the supplied products or wilful negligence.

Damage caused during transportation, storage or handling on site.

Damage caused by the emission of harmful products (eg gases, liquids), or by exposure to temperatures in excess of 60 degrees.

Damage caused during the fixing process.

Any defect caused by direct contact with wet or green timber, or any other corrosive substance.

Buildings within 1 kM of any coastline or tidal waterway.

Please Note:
  • The Cladco warranty begins at the date that materials are delivered to site, but not more than 12 months after manufacture.
  • The building must be registered with Cladco and a unique Warranty number issued, for any claim to be considered.
  • Warranties will not be issued until all products supplied by Cladco to the building under consideration, have been fully paid for.
  • Any costs arising from a claim under this Warranty must be agreed, in writing, by Cladco prior to any work commencing.