General Workmanship
The following comments are made as guidelines to be used when inspecting Dimond roofing and wall cladding systems during and after installation.
Roof Access
The means of access must be safe and secure, and should provide protection to the sheeting at the access point. Provision for cleaning or changing footwear to prevent the transfer of dirt onto the roof surface is recommended to minimise the risk of surface scratching damage.
Walking on Roofs
Soft, clean (free from dirt and clay) light coloured soled footwear must be worn. Foot placement should be close to purlin lines, and point loads should not be applied to profile ribs through careless weight distribution while walking. Avoid foot placement on the underlay edge of roof sheets. Translucent or Natural Lighting sheet must not be walked on.
Subsequent Trades
The work habits of trades accessing the roof must be controlled to avoid unnecessary damage from foot traffic, swarf, and storage of materials. Installed roofing that will be subject to further use (or abuse) during building construction should be protected by covers or temporary walkways. Care must be taken to protect and avoid scratching of the paint finish. The placement of scaffolding legs onto a roof should be avoided unless there is adequate support and protection to the roof finish to avoid damage. Penetration flashing should be placed as close to the ridge as possible to avoid large
catchment areas upstream of the penetration. All penetration flashings should be done in accordance with the MRM Code of Practice.
Dissimilar Materials
Care should be taken to ensure that incompatible materials have not been used, particularly through the installation of walkways and air conditioning equipment. Copper pipe must not discharge or allow water run-off onto the metal roof. Where necessary, water run-off from dissimilar metals should be contained and discharged separately from the roofing material. Wall cladding lapping onto concrete tilt slab or block walls must not contact the concrete. A small gap, such as 5mm, between or isolation strip is recommended.
Drilling and Cutting
When metal sheets require cutting, only shears, powered nibblers or hand snips should be used to leave a cleanly cut sheared edge. Any form of disc cut will nullify the material warranty. Cutting of Duraclad sheets can be with an abrasive disc or a fine tooth saw. Breathing protection should be worn to
prevent inhalation of dust. Cutting and drilling should be carried out clear of other sheeting material, and the drilling swarf immediately removed
from the surrounding sheet surface. Coil on cut edge protection lacquer may be required to be painted on all cut edges in severe marine areas to meet
warranty requirements. Check with Dimond.
Swarf
The particles of metal that result from cutting, drilling or self-drilling screw placement can adhere to the sheet surface and rapidly corrode, causing staining problems. The sheet durability is not affected provided the swarf particles have not penetrated the coating. Loose swarf must be removed without damage to the metal surface at least at the end of each day’s work including swarf driven by wind up under barge or apron flashings.
Remaining adhered swarf may be best left alone, provided no particles have broken the coating surface and the visual effect is acceptable. Roofs with heavy deposits of swarf or where the coating has been broken may require the affected sheets to be replaced. It is best trade practice to clean up after each day’s work to avoid swarf damage.
General Appearance
Screw fasteners should be installed to a straight line (staggered for lapped purlins). Extra care on wall cladding is required to achieve this. Flashings should run parallel with profile ribs or the building line. Sheet side laps should not exhibit excessive gaps, which can be controlled by careful sheet layout and side lap stitching if necessary.
Water Ponding
The installed roof and flashings must not exhibit water ponding. Buckling of profile pans caused by poorly formed lip downturns at gutter lines is a particular area of potential ponding that should be checked.
Sealants
Only neutral cure silicone sealants should be used. All sealed joints must be mechanically fastened, and excess sealant removed to prevent unnecessary dirt buildup. Joints in flashings or roof plane intersections should not be constructed in a way that relies entirely on sealant to remain weather secure. Sealant should only be used to seal between two metal surfaces, not fill holes or gaps.
Cleaning on Completion
All forms of debris must be removed daily from the roof surface to prevent scratching damage and moisture or dirt retention. On completion the roof should be thoroughly washed down and then inspected for any damage and any necessary remedial work carried out.
Strippable Film
Protective films must be removed within 1 day of product installation. Prolonged UV exposure will make removal difficult. The film must be removed from laps and under flashings during installation.
Scratches and Touch-up
Scratches that have not penetrated to the base metal (on coated materials) and minor surface abrasions should be left alone, as touch up painting will become obvious in time. Sheets with heavy scratch damage (e.g. scratches readily visible from a 3 metre distance that expose the base metal) should be replaced.
Buckled Ribs
Minor buckles that have occurred in profile ribs and will not retain water can be left alone. More severe buckles that will retain water or weaken the sheet should be pushed out from underneath, or be capped over with a rib section extending a minimum 50mm beyond the damaged section, fully sealed with silicone sealant and held onto the roofing rib with 4mm diameter blind aluminium rivets each side.
Major buckles that affect more than 1/4 of the ribs in line across any sheet will cause a severe loss of strength, and in such cases the sheet must be replaced, e.g. if more than 2 adjacent ribs are buckled on the same purlin line, the sheet’s ability to hold load is reduced and it must be replaced.
