Most people think that a good hoover will get rid of them. But no amount of hoovering will shift them. In the trade they are known as “Filtration Marks”, "Venting Marks" or "Draught Marks". Over a period of time these dark soiled areas gradually become more noticeable on your carpet.

It’s Not Dust, So What Are They And What Causes Them?

The main cause of these lines is air flowing where carpets have not been put down 100% correctly. If your carpet fitter hasn’t got the gripper rods close enough to the skirting, this will mean there will be a gap. Black lines are caused by air moving through wall cavities, under the gaps between floorboards and skirting or through heating or air vents.  In severe cases we've seen black lines extend more than 2 inches from skirting boards and around central heating pipes where they come up from the floor to a radiator.

Where there is a flow of air your carpet acts like a filter. Filtering out microscopic particles that flow under the floor and out through the gap between the gripper rod and the skirting board.

Removing Filtration Marks

Filtration mark soiling can be greasy and requires professional cleaning using the right processes to get a satisfactory result. We always do a free of charge site visit so we can assess how much soiling there is, and the length of time it has accumulated. The amount of airflow, the colour of the carpet and type of carpet fibre will also determine which carpet cleaning process we use and the likelihood of success.

Stopping Filtration Marks Coming Back

After we have cleaned your carpet, we will apply flexible silicone sealer into the gap between floorboards and the skirting.  Then we refit the carpet. This will prevent the filtration marks from returning.

Right Processes Right Results

We come across filtration marks in our clients’ homes and businesses at least once a week. Our technicians are highly trained and have a wide range of cleaning systems at their disposal. They will use the right cleaning system to get the very best results.

We can usually remove filtration marks to an acceptable level and stop any further damage.

At Knight & Doyle we’ve been cleaning carpets for over 20 years. Our advice is free of charge so please contact us with any questions regarding carpet or upholstery cleaning. Get in touch today on 01543 401043.