Customer Service: +61 3 8470 7300
  • Homepage
  •  New 

    Effect of weed killer on galvanized steel columns

Effect of weed killer on galvanized steel columns

Send to printer
End of Line

To control grass growth around the base of galvanized steel streetlight columns, maintenance contractors have traditionally used weed killers. While effective on grass some weed killers, or herbicides, can seriously affect the life span of the columns.

The most common weed killers, such as Roundup, contain a pelargonic acid which is a type of organic carboxylic acid. Pelargonic acid, like all organic carboxylic acids, is corrosive to many metals, including galvanised steel. 

The Material Safety Data Sheet (MSDS) for Roundup warns against the contact of the herbicide with galvanized steel. The herbicide Roundup is water-based and the presence of an acid in the chemical formulation ensures that the corrosive compound leaches into soil affecting the galvanized coating of the in ground section of the light column.

As a result of using a weed killer such as Roundup there is accelerated corrosion of the galvanized streel streetlight columns in the areas that have come in contact with the spray. This corrosion can shorten the expected life span of the column, from the usual 25 years down to as low as 10 years. It can also cause the column to fail by breaking at the site of the corrosion.

CSP Pacific recommend the use of an alternative method of grass control around galvanized steel columns such as a mowing strip.

If a herbicide is used to control vegetation at the column base, the formulation should be assessed by a specialist to ensure that the chemicals contained are not corrosive to galvanized steel.

Truely organic herbicides do not contain harmful chemicals but, depending upon the application, they may be less effective than synthetic herbicides and therefore are usually used in conjunction with mechanical weed control practices.

For more information: email: or phone CSP Pacific on 0800 655 200


NZ Regional Map

Auckland, Northland and Central Nth Island

Ph: +64 9 634 1239

Fx: +64 9 634 4525

more info


ArmorZone™ TL-2 Plastic Barriers out in force for Baypark to Bayfair upgrade

31 October 2018: Tauranga is a city on the move, literally and figuratively, claiming the title as the ...

more >>

M2PP – Miles of life-saving barrier

26 August 2018: The 18km, four-lane Mackays to Peka Peka Expressway that takes SH1 along the Kāpiti Coast is the ...

more >>
DocLaunch Page Launch Commonon Launch
Auckland Lower Nth Island South Island