Guardrail rust and corrosion can be seen on building guardrails and exterior railing around the world. There are a number of causes of guardrail rusting. In this article we’re going to look at how rust is caused as well as how to prevent future rust in your railing systems.

What are the causes of guardrail rust?

Guardrail rust is primarily caused by three contributing factors, and you can essentially boil these down to one big culprit: improper choices in the railing construction and installation.

In other words, rust is completely preventable by making good choices in the selection of your manufacturer and your installer. This is important, because corrosion from your rail can cause spalling (see our article on what causes spalling on balconies if you’re wondering why your concrete slabs are falling apart). Early detection and prevention of spalling can save you a lot of money — concrete repair gets to be very expensive, very fast.

Here are the three primary causes for guardrail rust:

  1. Embedded posts in the concrete slab: This is an issue we see on older railings or on railings installed by inexperienced railing suppliers. An embedded post in the concrete slab will not last long in coastal or salty environments.
  2. Improperly specified grout and steel post inserts: bad grout is one of the biggest culprits of guardrail failure. Many contractors will skimp on the grout. You want to use epoxy-based impervious grouts to isolate and seal the cementitious substrate from the railing post.
  3. Incorrect hardware for the application or environment. Many less experienced guardrail suppliers and installers will make this mistake in screw and connection hardware they choose. The selection of quality screws and connection hardware should be based on the materials of the guardrail. Coated screws will cause major rust problems which bleed into the concrete, causing failure of both the railing as well as the concrete slab. Bad screw selection can easily happen if you leave the installation up to a contractor instead of a professional railing installer.

Each of the above issues can effect railings made of any material, including aluminum. A fourth cause that is the use of iron and steel railings, which will rust over time. Wrought iron, which has low carbon content, is rust-resistant, but will eventually rust if not maintained.

How do you repair rusting railing?

Mitigation plans for rusted railing can be effective when the rail itself it showing signs of rust. However, if you have rust appearing at the embedded post, it typically will require replacement of the rail.

The appearance of rust on your railing is typically a sign that you should be looking into modernization for your railing systems. Poma provides a number of options to modernize your guardrail with long-term performance and contemporary aesthetics. Each of these options is built on patented anchor technologies which ensure that the concrete slab is protected from deterioration.