Premier Mastic Asphalt


Typical Specification Mechanically Fastened

1. Deck

Install the Profiled metal deck to the required falls in accordance with the manufacturers instructions. Ensure that the deck is firmly fixed, clean, dry, smooth and free from frost and contaminants.

2. Grid Reinforced Polyetylene Vapour Control

Install Icopal Vapour Control Layer to a manageable area. Joints in the Vapour Control Layer must be a minimum of 150mm and joined with Icopal Monobond LT tape. The overlap must be made on the crown of the metal deck and seams must be hand rolled to secure the joint. Hold down the Vapour Control Layer by placing and fixing the insulation as detailed in the mechanical fixing layout drawing ref.......... Turn the Vapour Control Layer up all upstands, kerbs and other penetrations and wrap around the edges of the insulation turning back to provide a complete seal.

3. Thermal Insulation Foilboard

Install Icopal Thermazone Foil Roofboard 2400 x 1200mm closed cell polyurethane insulation board ........ mm thick, loose laid over the Vapour Control Layer. All boards must be laid breaking joint with long edges running at right angles to troughs and ends fully supported. Insulation boards to be fixed using at a minimum rate of 11 fixings per board using Sure-Weld long HP-X fasteners and Insulation plates. On completion of fixing ensure that the boards are in good condition, well fitting with no springing, flexing or rocking.

4. Membrane Attachment

Install Sure-Weld TPO membrane to provide a secure and watertight roof with membrane free from wrinkles or blemishes. Side laps are mechanically fixed at centres as described on the fixing scheme-drawing ref ....... All sheets to be mechanically fixed around the perimeter and all apertures or attached to Sure-Weld pre formed metal flashing for securement. All mechanical fixings must be Sure-Weld HP-X and Pirhana plate washers and fitted in accordance with the recommend equipment to ensure correct and consistent insertion. The fixing scheme drawing illustrating the various zones of fixing density will be issued on receipt of order. The method of fixing must be followed correctly in order to meet wind uplift resistance requirements.

5. Side Lap Welding

Overlap adjacent Sure-Weld sheets 140mm to form laps where mechanical fixings are located and a minimum of 50mm in all other locations ensuring water will drain over and not into them. If the membrane has been exposed for more than seven days clean and dry the joint surfaces using Sure-Weld membrane cleaner for the whole length of the lap prior to welding. Seal all side and end laps by heat welding ensuring a 40mm hot air weld using manufacturers recommended welding machinery. All laps should be checked after the completion of welding and the membrane has cooled by drawing a metal scribe along the joint in a firm but non-destructive way. All cut edges to be finished with a 3mm bead of Sure-Weld TPO cut edge sealant following welding. The operation should be carried out as work is in progress.

6. Corners

Internal and external corners should be formed using Sure-Weld TPO pre formed corners, or site formed using Sure-Weld TPO flashing

7. Perimeter details

Install Sure-Weld TPO metal sheet bent to suit the detail and fixed in accordance with the relevant detail drawing.

8. Terminations

Install Sure-Weld termination bar where a surface mounted termination is required. Install a bead of Sure-Weld cut off mastic behind the membrane at the top of the termination Install Sure-Weld termination bar fixed at max 300mm centres with the appropriate fastener. Do not wrap termination bar around corners. Cut all termination bars at corners to accommodate expansion and contraction. Install Sure-Weld water cut off mastic completely filling the channel on top of the termination bar and point to eliminate voids.

9. Outlets

Install suitably sized Sure-Weld roof outlet in accordance with the current fixing instructions. The Sure-Weld outlet has a rubber “O” ring fitted to the spigot. This “O” ring provides a seal to the internal diameter of the down pipe. The outlet has a reinforced TPO flange that should be fully supported and mechanically fixed. The Sure-Weld TPO field membrane must be fully sealed to the flange.

10. Walkways

Install Sure-Weld TPO walkway to designated areas by hot air welding along the long edges to main field membrane. Provide 100mm wide gaps to ensure that the walkway does not bridge over welds in membrane.

11. Pipes and Vents

Cut membrane around the roof penetration and secure to the deck. Install Sure-Weld pre-moulded pipe flashing 25 to 150mm diameter. Hot air weld the flange of the pipe flashing to the membrane surface and seal to the pipe with Sure-Weld water cut off mastic and stainless steel clamping ring or install a counter flashing or weathering cravat to the projection.

12. Lightning Conductor Strip

Install Sure-Weld lightning conductor pads to provide attachment of the lightning conductor strip to the finished waterproofing. The pads should be fixed in a straight line with centres not more than 1m. At changes of direction the pads should be installed as close as practical to either side3 of the juncture. The pads are secured by heat welding.

13. Approved Applicators

All work should be carried out only by an approved Sure-Weld applicator and in accordance with the Manufacturers current application guidelines.

14. Storage of Materials

Materials should be delivered to site in the original packaging and bearing the appropriate Sure-Weld labels. Store rolls of Sure-Weld membrane in clean, dry conditions. Insulation products must be kept dry and protected from wet weather during storage and installation. Care should be taken when loading roof areas to ensure that material is positioned over structural supports and that adequate protection is taken to protect the deck and insulation from damage.

15. Incomplete Work

At the end of each working day ensure adequate protection of the insulation by temporary seal and ensure the laying sequence enables all temporary sealing to occur down the slope and not against the flow of water.

16. Protection of Work

Ensure that the roof is not used as a working platform unless fully protected to the satisfaction of the CA. No paints, solvents or substances harmful to the membrane are allowed to come into contact with the roof surface. No building materials are stored on the roof without adequate protection. Finished roof areas should be adequately protected from damage by subsequent building operations.

17. Adverse Weather

Sure-Weld TPO should not be laid in wet or damp conditions and work should be suspended in severe or continuously wet periods unless an effective temporary roof is provided over the working area. If unavoidable wetting of the construction occurs, take prompt action to minimise and make good any damage.

18. Completion/Quality Assurance

Upon completion, Icopal should be notified to make a final inspection of the work. Roof areas should be clean with all outlets clear and running free.

All work by third parties necessary to provide a watertight finish should be completed. The approved applicator should ensure attendance at the final inspection.

Any defects where possible should be completed whilst the Icopal technician is on site. Warranties will only be issued when the completed roofing system has been deemed to be in compliance with the specification and working details applicable for the Sure-Weld Roofing System. Upon satisfactory completion the Sure-Safe Warranty will be issued to the client via the approved applicator.