1- Your roof may fail under the added weight…
The first consideration must be whether or not the building structure will bear the weight of another layer of recommended gauge steel sheets and supporting framework. Calculations must factor in snow loading.
2- More holes = more problems down the line
‘Through fix’ installations that utilise the existing purlins must necessarily involve drilling further holes in the existing sheet, risking moisture penetration and air leakage leading to condensation.
3- You will create the issue of CONDENSATION…
Where the old roof is retained as a liner, a new vapour protection layer must be added if it cannot be sealed. The VCL should be located above what will become the internal sheet but is difficult to seal when punctured with fixings for the support brackets for the new skin, risking ‘cold bridging’.
4- Matching performance properties for all other materials
A vast array of support and ancillary fixings, sealants and thermal performance materials must match the design life guarantee of the chosen over-sheet system.
5- Over-sheeting causes heavy disruption to your site
A strictly controlled programme involving large and heavy deliveries, storage, movement of men and materials and handling must be carefully planned and safely managed.
6- Recoating is inevitable!
Like the original sheet, the over-sheet will itself need recoating as it reaches its normal expected repaint schedule. The same factors affecting performance will prevail on the factory coating of an over-sheet option. Cut edge corrosion will almost inevitably occur during its lifetime.
7- Recoating is the sustainable choice…
Steel sheet production requires large resources of finite raw materials and energy. Having a steel roof already in place requires only recoating to protect it indefinitely.
8- Life-cycle costs far greater with over-sheeting
Over-sheeting means double roof sheet disposal at building end of life.
9 – Giromax® Roofcoat is revolutionising the coating industry…
Giromax® Roofcoat is the NEW cut edge corrosion treatment from Giromax Technology, achieving better results for longer. It can be sprayed directly from the tin. No mixing required. And like previous versions is fully moisture tolerant which means it can be applied to wet surfaces, hardening to a tough elastic coating with high impact and dirt resistance. This single coat system also comes with a 20 year guarantee.
Planned repainting will extend profiled metal sheet life indefinitely, maintaining the strength and value of the building without disturbance. Over-sheeting by comparison is heavy, increases the risk of leaks & condensation and leaves the same coating failure dilemma further down the line. In essence, the roof protection is now provided by a sheet with characteristics and weaknesses possibly worse than that being over clad, with an unnecessary layer of steel effectively doubling sustainable planned maintenance and life cycle costs.