Rusting describes the process of corrosion of iron and steel. New Jersey home inspectors and homeowners should have a basic understanding of how Rust develops and how to take steps to help manage it. Rusting is more than just a cosmetic problem. Rusting can lead to serious structural problems and deterioration. Rusting is a common form of corrosion which is an electrochemical process leading to the deterioration of a material. Rust typically appears as a red, brown or orange flaking or pitting metal surface.
Oxidation is the process in which rust is formed when oxygen comes into sustained contact with iron or steel. When iron or steel comes into contact with water and oxygen the result is rusting. Once rust starts to form its porous surface will trap additional liquids and lead to further corrosion.
Some metals can rust, and other metals cannot rust. It is helpful for New Jersey home inspectors to be able to differentiate between metals that can rust and metals that cannot rust. Magnetic metals can rust. Both steel and iron are magnetic while other metals such as zinc, copper, aluminum, brass, silver are not magnetic. Nonmagnetic metals do not rust. Iron which can rust is typically dark in color. Galvanized steel has a dull appearance while stainless steel is shiny and bright. Copper which is commonly using household wiring has a bright reddish color although it can turn green when exposed to the air. Aluminum a building material commonly used in siding is silver colored and shiny.
The only metals that can actually rust are iron and steel which is an alloy of iron. Other metals may become corroded, but they do not meet the definition of rusting technically. An example of this is the corrosion of copper which turns the copper green and the screen color is called patina.
Rust has considerably less mechanical strength then its originating metal and it will not adhere but will gradually flake off, weakening the structure. New Jersey home inspectors should inspect for rust damage in the following locations.
Water pipes:
Home inspectors should operate water at each fixture in the home. Water that is brown, orange, or red indicates rusting water supply pipes. This is especially true with old cast iron or steel water pipes. Rusting water pipes will eventually leak and cause flooding and damage. A full visual inspection of the exposed water supply pipes should be done in order to assess their condition. There will also be piping behind the walls. The piping behind the walls is likely to be in a similar condition to the visible piping in the basement or crawlspace.
Metal chimneys:
Th weather, tree leaves and organic debris will eventually eat away at the galvanic coating on metal chimneys and chase covers. This will leave the chimneys and chase covers vulnerable to rusting. The weakened metal will allow water to enter the chimney causing further rusting. This rusting condition is less common in newer stainless-steel chimneys and chase covers. Home inspectors should fully inspect the exterior metal chimneys and chase covers for rusting. If significant rusting does exist, then NJ home inspectors should recommend replacement to their clients. Often this type of rusting can be seen by using binoculars or a camera with a strong optical zoom.
Above ground fuel oil tanks:
Most oil tanks are made of steel which makes them vulnerable to rusting. Heavily rusted fuel tanks will leak and can cause expensive environmental damage. Oil tanks should be protected from the weather where possible. NJ home inspectors should evaluate the condition of any above ground exterior oil tanks and recommended to their clients that they protect the tank from weather exposure. Any significantly rusting oil tanks should be recommended for replacement.
Nails and screws:
Nails and screws that are not stainless steel or galvanized will rust when exposed to the weather. The rusting of nails or screws when installed in wood indicates the wood is moist. Rusted nails or screws will not provide adequate support which increases the probability of structural failure or collapse. One area particularly vulnerable to rusting is the fastening of joist hangers to the deck ledger board. NJ Home inspectors should thoroughly inspect for rusting joist hanger nails and joist hangers. Significantly rusting hangers or nails will compromise the safety of the deck structure and clients should be alerted to the issue and replacements should be recommended.
Electrical panels:
A rusting electrical panel or interior terminals that have rust or corrosion is a significant safety hazard. The rusting indicates the presence of moisture inside the panel box. Moisture typically enters the panel box through a main service wire that is in poor condition or frayed. Sometimes the duct seal at the top of the meter pan is cracked or brittle which can allow moisture or water inside. A NJ home inspector should as required by the NJ home inspection regulations perform a full inspection of the electrical panel box including removing the panel box cover.
Support columns:
Rust damage to steel support columns can be a significant issue found while inspecting homes. When the columns rust the structural integrity of the columns weaken which then weakens the structure of the home. Columns that lose their ability to hold loads present a major safety hazard. The columns support the weight of the floors above creating a load path to the foundation or footings. The damage caused by the rust can be a variable depending on the severity of the oxidation. Home inspectors should alert clients to support columns that are compromised by rusting due to the inherent safety hazard that exists. Any severely rusted columns should be recommended for replacement.
Steps to minimize rusting:
New Jersey home inspectors should have a basic understanding of steps that can be taken to minimize rusting of iron or steel. One of the basic ways to help prevent rust from forming is to paint or coat the metal. Painting creates a barrier between the metal and the moisture in the air. Lubrication can also help prevent rusting by lowering friction between metals. Home inspectors should recommend to clients that they use a good quality lubrication on moving metal parts to help keep rust at bay. The most important thing at minimizing rust is keeping moisture under control. Home inspectors should recommend the use of dehumidifiers in high humidity areas. They should also recommend that any plumbing leaks be quickly fixed and repaired.
Rusting is a product of metal exposure to water and oxygen. New Jersey home inspectors should properly inspect for rusting on important components. Home inspectors should recommend corrections be performed on any rusting components that may compromise safety. Lastly, they can educate their clients on how to minimize the effects of rusting in the home.