We stock huge quantities of metal rainwater systems, metal drainage solutions, metal roofline and aluminium architectural products – so that you can order when you need them and not have them taking up space on site.
BUT if you do need to store our products onsite there are IMPORTANT actions you must undertake to avoid adverse reactions to outside temperature and moisture while the products are still packaged/wrapped – which will not affect the metal products once unwrapped and installed – and which are completely avoidable with the following care.
Galvanised Steel (not colour coated variety)
Adverse reaction if left unwrapped: White Rust
If galvanised steel products are not stored correctly, they can be affected by the corrosion known as “white rust”.
In accordance with industry best practice, and to avoid this, reasonable precautions must be undertaken by the customer to reduce the risk of white rust.
All galvanised steel products should be stored inside or under cover, in a clean and dry environment, free from any chemical interaction (i.e. tree sap, sea spray, diametric metals
(see our galvanic scale graphic for more about this)
As rapid temperature changes lead to condensation, and as a consequence, to white rust on galvanised steel these products must be kept consistently above ‘dew point’ temperature and at as constant a temperature as reasonably possible.
Keep on a wooden or metal pallet to avoid contact with the ground.
It is best practice to avoid storing galvanised steel material outside. And we hold stocks for next day delivery, so you don’t have to. However, if storing galvanised steel products outside becomes unavoidable, the below precautions should be taken in addition to the above steps:
- Build a simple frame around the galvanised steel products and cover them with a waterproof film, tarpaulin or similar cover
- Allow for space between the galvanised steel products and the waterproof cover so that air can circulate freely
- Store the galvanised steel products, free from contact with the ground, and at a slight incline so that rain can drain off the cover
- Check the galvanised steel products storage area regularly to avoid a build-up of damp, condensation or rainwater.Be aware that products stored at bottom, top or centre of a pallet may become wet through condensation and that it may not be possible for this water to either evaporate or to ‘run off’
- Keep the period of outside storage as short as possible, especially during the summer, as elevated temperatures speed up the white rust process
We can deliver next working day when ordered before Noon, so you can order ‘just-in-time’ to avoid the need to store your galvanised steel rainwater products outside on site.
Polyester powder coated (PPC) Aluminium
Adverse reaction if left unwrapped: Blanching
If polyester powder coated (PPC) Aluminium products are not stored correctly, they can be affected by “blanching”. Caused by water ingress in between the protective polythene wrapping and the coated aluminium, though a bit unsightly, it is does not harm the material or the coating in any way and can be removed*.
In accordance with industry best practice, and to avoid this, reasonable precautions should be undertaken by the customer to reduce the risk of it occuring:
- All polyester powder coated products that are stored outside should be covered with a tarpaulin or similar to guard against water ingress into the protective polythene wrapping
- The manufacturer/Alumasc’s BBA certificate also advises: “coated products should be stored under cover and away from the possibility of impact and the effects of the weather.”
“If not stored correctly a phenomenon known as “blanching” can occur on PPC coated items under certain conditions.“
If water becomes trapped within the polythene wrapping and left exposed to sunlight and humidity changes through daylight and night-time, any moisture or condensation trapped can be forced into the coating and the result can be a surface colour change similar to that seen during a permeability test.”
N.B. AkzoNobel have confirmed there is no detrimental effect to the powder film and *controlled reheating of the component can usually rectify the appearance.
Or get in touch with the friendly, knowledgeable team at Rainclear Systems. Call 0800 644 44 26 or email sales@raiclear.co.uk