The use of aluminium in building construction involves its close association with many other materials. Aluminium is compatible with most, but there are a few which require some special attention.
Metallic building materials
Providing the plating is correctly applied there is no acceleration of attack on aluminium.
Copper and copper alloys
Contact between copper and aluminium will result in severe corrosion. Where joining these metals is unavoidable always use plastic ferrules and washers. Water must not be allowed to drip from copper and its alloys onto aluminium.
Iron and steel
For relatively clean rural and urban atmospheres the contact areas of steel should be painted with a bituminous or red oxide / zinc chromate paint. Existing steelwork should have any rust removed by scratch brushing. Lead-free paint should be used on any new steelwork that will be in contact with aluminium.
In extremely corrosive environments, a nonabsorbent gasket, such as PVC or similar should be used in addition to paint.
Aluminium will not normally be corroded by contact with lead. In aggressive atmospheres however, both facing surfaces should have a bituminous paint applied.
Stainless steels polarise and become inert to aluminium, and can therefore be safely used together.
Aluminium is not corroded by contact with zinc. In polluted atmospheres it is advisable to coat both facing surfaces with bituminous paint. Please refer to page 143 for information on bi-metallic corrosion.
Non-metallic building materials and chemicals
Aluminium is resistant to asphalt.
Brickwork and stonework
Where aluminium cannot be separated from masonry by using spacers, the metal should be treated with two coats of bituminous paint or strips of a suitable inert material used.
Slight etching of the metal may occur when lime is released during the setting period.
Under wet conditions some corrosive action can result, and it is recommended that the aluminium be treated with a protective compound or bituminous paint.
In normal above-ground dry building floors and walls no protection is required.
In very damp conditions the soluble elements of certain insulating materials may leach out. To prevent any possibility of attack an inert barrier should be introduced between the surfaces.
Some slight staining may be caused as the material sets.
Aluminium is resistant to rubber.
Aluminium is resistant at any temperature to turpentine.
Aluminium is resistant to varnish.
Wood and hardboard
Under dry conditions there is no interaction between aluminium and seasoned woods. Some unseasoned woods however have an acid reaction and cause corrosion in the form of pitting. In damp or wet situations, facing surfaces or joints are best protected by sealing the wood with aluminium or bituminous paint.
Aluminium is resistant to wood creosote.
Some wood preservatives are corrosive to aluminium, including those containing copper and mercury salts.
For more information about Gooding Aluminium, visit our website at: www.goodingalum.com