Causes and consequences

Ochre deposits are the result of a chemical reaction or a biological process, which can occur individually or simultaneously.

The chemical reaction occurs when the iron in the soil migrates toward the drain with the water and forms an iron hydroxide slurry on contact with the air.

The biological process occurs when ferrobacteria, a type of bacterium that contains iron, is present in the groundwater; it produces a gelatinous mass as a result of the oxidation of iron in contact with the air.

When the biological process is combined with the chemical reaction, the oxidation effect is considerably increased.

In both cases, the result is the formation of a viscous deposit on the walls of grooved drains. It is this deposit that is commonly referred to as iron ochre

Although an ochre deposit issue is not harmful to human heath, it must be managed by the owner of the immovable affected by the problem.

Regular and proper maintenance of the drains will prevent costly work down the road.

With the proper information, the buyer can take the necessary steps to enjoy his property.

Impact of the presence of ochre deposits

Ochre deposits engender several problems affecting buildings. In particular, they cause the formation of ochre-coloured sludge in the rainwater catchment basins and in ditches.

They also create reddish deposits on the concrete slab of basements, which emit sulfur-like odours.

They clog agricultural drains. As runoff water is no longer channelled away from the foundation, it infiltrates the basements at the junction of the foundation walls and the slab.

Ochre deposits also clog backflow valves.