Iron ochre: can you buy a house that has it?

In short

Iron ochre is a rust-coloured, jelly-like deposit formed when bacteria transform iron dissolved in groundwater. It gradually clogs the French drain and can lead to basement water infiltration. It cannot be eliminated: it is managed with an accessible drain, cleanout ports and regular maintenance. An affected house can be bought, but knowingly and with the right budget.

How it shows

An orange or brown, slimy deposit in the sump pit, in the drain cleanouts or at pipe outlets, sometimes with a sulphur smell. A sump pump that runs often, or a damp basement despite a drain, are other signs.

Sandy, silty or peaty soils, a high water table and iron in the water favour the phenomenon. Several Quebec municipalities have mapped at-risk sectors and require cleanout ports on the drain for new construction.

What it changes for the purchase

The question is not “is there any?” but “is the drain accessible and maintained?”. A drain with cleanouts, flushed every one to three years, with a documented history, is a managed situation. A drain without cleanouts, never flushed, in an at-risk sector, is a potential project.

The inspector cannot see inside the drain. A camera inspection of the drain, by a specialist, is the only way to know its condition.

Orders of magnitude

Periodic drain flushing runs in the hundreds of dollars. Adding cleanout ports, a few thousand. Full replacement of a French drain with excavation around the foundation, in the tens of thousands, depending on perimeter and landscaping to redo. Orders of magnitude to confirm with quotes.

What to do before buying

Ask the seller for drain-flushing invoices and the date of the last service.
Check with the municipality whether the sector is mapped as at risk for iron ochre.
Have the drain camera-inspected during the inspection condition if there are signs.
Budget annual maintenance as a fixed cost of the house.

What Clarity does with it

Clarity picks up the signs noted by the inspector (deposit in the pit, busy pump, dampness), separates them from confirmed findings, and puts the camera inspection on the list of checks to do before lifting the condition.

Does your report mention this? Clarity tells you in five minutes what is priority, what to have checked and what to ask the seller.

Analyze my report

Frequently asked questions

Is iron ochre a hidden defect?

Not in itself. A seller who knows about it must disclose it. If the signs were visible or disclosed, the buyer is deemed to have accepted them. Each case depends on what was disclosed and what a prudent buyer could see.

Can iron ochre be removed for good?

No. The bacteria live in the soil. Its effects are limited by an accessible, maintained drain and sometimes complementary measures (adapted sump, membrane), but it is not eliminated.

Does a dry basement prove there is no iron ochre?

No. The drain may be clogging without water having come in yet. Hence the value of examining the sump pit and the cleanouts.

Sources