Delcote® 25 Architectural Roof Coating for Metal Roofs (25 Year BBA) - Silicone coating

Anti-corrosion coatings.

Guidance for specification option:

Roof Sheets

Any roof sheets which are perished beyond structural safety should be removed and replaced with new. New PVC Plastisol sheeting should be solvent wiped to remove residual plasticizer. Loose coatings should be removed from the entire surface. Make sure not to miss areas around fixings, bolt penetrations and side laps. Removal may be actioned by utilising a pressure washer fitted with a rotating spinning head capable of delivering a minimum of 3000 psi. The surface where required should be prepared to Swedish Standard ST2 by using hand held power tools. No oil, grease or dirt, should be visible to the naked eye. All poorly adhered mill scale, rust, swarf, coatings and foreign matter must be removed. Passivate (T-wash) unweathered or shiny galvanised substrates with suitable mordant solution. An adhesion test should be carried out to any remaining well adhered coatings. Note: Do not at any time clean the surface with soap detergent. This action would leave a residual film and may adversely affect adhesion. Ensure all surfaces to be treated are dry by using a mechanically driven leaf blower before the application of Sharmans products. 

Sheet Cut Edges

Check existing overlaps for excessive movement and insert additional fixings as necessary. If the gap between the sheets is greater than 5mm a stitcher screw or rivet should be used to close the sheets together. Loose and flaking coatings should be removed to achieve a sound feathered edge. Remove all rust and white (zinc) salts, by thoroughly cleaning/ abrading to Swedish Standard ST3. Ensure the surface is fully keyed and not polished. All debris, including any grinding swarf and non adherent staining must be removed prior to application. Dry the substrate using a mechanically driven leaf blower. Thoroughly clean the surface using Isopropyl Alcohol.

Sheet Fixings

Check the integrity of the existing fixings. Suspect fixings should be replaced in accordance with recommended standards. Any plastic caps that are not integral should be removed. Loose fixings should be tightened. All remaining fixings should then be treated with Seamsil® Base Coat as detailed below.

When Replacing Fixings

Please consult Sharmans Technical Services. 

Anti-corrosion coatings.

Guidance for specification option:

To Overlaps, Ridge/ Flashing Joints & Tops Of Rooflights

Seamsil® Sealant is gun-applied into the gap between the upper and lower roof sheets, as close to the edge of the upper sheet as possible, forming a complete bridged seal. The Seamsil® system may also be used on the vertical lap joints if the roof suffers from water ingress due to incorrect lap formation. Seamsil® Base Coat Seamsil® base coat should be applied at least 25mm above the edge of the roof sheet or either side of the overlap, and where applicable a further 10mm beyond the prepared exposed metal to ensure complete coverage. For neat aesthetics, the coating should be applied in a straight line. To aid this, a pencil line or a straight edge can be used. At Overlaps Whilst the Seamsil® Sealant is still wet, apply Seamsil® Base Coat by brush at a minimum wet film thickness of 220 microns. Work in a smooth upward motion over the sealant, ensuring complete coverage of all exposed and prepared metal. Allow to cure to a tack free state. The finished Seamsil® treatment must form a fillet across the joint that visually obscures the leading edge of the top sheet. 

At All Other edges

Apply Seamsil® Base Coat by brush at a minimum wet film thickness of 220 microns, ensuring complete coverage of all exposed and prepared metal, and encapsulating the sheet edge. Allow to cure to a tack free state.

At Fixings

Brush apply one liberal coat of Seamsil® Base Coat over and around the roof fixings, ensuring a full encapsulation is achieved, especially at the base. Allow to cure to a tack free state.

Delglaze® (where applicable)

For rooflights being coated using Delglaze®, please refer to the Delglaze® System Specification and the relevant Product Data Sheets. When using Delglaze® in conjunction with Delcote®, ensure that the Delglaze® treatment is carried out first, and that the rooflights are then suitably covered in a safe manner to prevent overspray. 

Manufacturers system recommendations.

Guidance for specification option:

To Overlaps, Ridge/ Flashing Joints & Tops Of Rooflights

Seamsil® Sealant is gun-applied into the gap between the upper and lower roof sheets, as close to the edge of the upper sheet as possible, forming a complete bridged seal. The Seamsil® system may also be used on the vertical lap joints if the roof suffers from water ingress due to incorrect lap formation. Seamsil® Base Coat Seamsil® base coat should be applied at least 25mm above the edge of the roof sheet or either side of the overlap, and where applicable a further 10mm beyond the prepared exposed metal to ensure complete coverage. For neat aesthetics, the coating should be applied in a straight line. To aid this, a pencil line or a straight edge can be used. At Overlaps Whilst the Seamsil® Sealant is still wet, apply Seamsil® Base Coat by brush at a minimum wet film thickness of 220 microns. Work in a smooth upward motion over the sealant, ensuring complete coverage of all exposed and prepared metal. Allow to cure to a tack free state. The finished Seamsil® treatment must form a fillet across the joint that visually obscures the leading edge of the top sheet. 

At All Other edges

Apply Seamsil® Base Coat by brush at a minimum wet film thickness of 220 microns, ensuring complete coverage of all exposed and prepared metal, and encapsulating the sheet edge. Allow to cure to a tack free state.

At Fixings

Brush apply one liberal coat of Seamsil® Base Coat over and around the roof fixings, ensuring a full encapsulation is achieved, especially at the base. Allow to cure to a tack free state.