Building inspection and iron ocher

So-called Iron Ocher is a phenomenon that occurs underground but, in itself it is not toxic and does not represent a health hazard. An abnormally high humidity in the basement is often the first sign of its presence in high concentration.  Generally in more serious cases, there is the appearance of reddish deposits on the concrete slab and sulfur smell is sometimes present.

Although the agriculture community has long known about the Iron Ocher problem, for residential homeowners this has been a more recent occurrence. In order for Iron Ocher to appear, special conditions need to be present such as the presence of iron bacteria in a high water table and dissolved iron flowing through the foundation drain system. When the mixture comes in contact with air, a reaction occurs causing the appearance of iron hydroxide in the form of a red mud which covers the walls of the drain pipe causing water infiltration at the base of the foundation wall into the basement.

Unfortunately, there are no methods to stop the proliferation of iron ocher and research on the matter has shown that the phenomenon can’t be eliminated. However, to prevent infiltration in the basement, the installation of maintenance chimneys have been used to periodically flush the foundation drain system. This approach does not solve the problem, but it has prevented the clogging of the foundation drain system. Other methods can be used such as raising the foundation or waterproofing the foundations but they are seldom considered because of the significant investment required.

Where evidence of the presence of Iron Ocher is found further investigation is required by a plumbing specialist who will be able to assess the condition and recommend solutions to control the phenomenon.