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Saturday, 9 March 2013

Draught Marks (a.k.a. Filtration Soiling) on carpets

What is draught marking?

Draught marking appears on carpets as dark soiled areas or spots around the edges of rooms or under doorways. In extreme cases it is found across the middle of a room in the configuration of the floorboards.

It is also known as filtration soiling, fogging or dust marks. The cause is always the same. Contaminated air blows through or across the carpet and the carpet acts as a filter, removing the dirt from the air. The resultant draught marking is both unsightly and a problem to remove.

The contaminated air gets to the carpet through:-

  • Gaps under the skirting board creating black lines
  • Gaps between the floorboards allowing dust travelling upwards
  • Holes in the carpet caused by nails or carpet fitting tools
  • Gaps under doors where the air concentration is high
  • Gaps under the bottom of curtains, usually creating wavy lines (where the curves of the curtains hover above the carpet)
  • Air vents close to the carpeted floor allowing dust travel through it

The best method of preventing draught marking ruining the look of your new carpets is to specify a draught proof installation. This prevents the movement of air through the carpet and may involve the following steps before the carpet is installed:-

Laying sheets of hardboard on top of the existing floorboards
Taping all the hardboard joints to prevent leaks of air
Laying paper on top of the hardboard to add extra draught proofing
Using flexible mastic to seal the gap between the skirting board and the floor.

If these measures are carried out before the carpet and underlay are installed then it is unlikely that very much draught marking will occur .

Draught marking could possibly be removed by cleaning (depending on how fresh it is), but not cured. The microscopic airborne soiling is tenaciously oil bonded to the carpet fibres. The degree of success in the removal of the soil depends on the nature of the soil (pollution) and the length of time that it has been present. At CleanPro we have researched and tested many ways of removing draught marking and we are confident that we can remove the majority of this soiling if it is fresh, but only make an impact on older draught marking by removing only some of it (basically the longer it is in the carpet, the more difficult it is to remove). However a draught marking problem cannot be cured by cleaning alone as the soiling will return if the contaminated air is allowed to continue to flow through or across the carpet! [we will not use harsh high ph cleaning agents in a desperate attempt to try to remove all of this soiling - as this action alone will probably remove colour from the actual carpet fibres, thus leaving us in a situation where we would be asked to replace the carpet!].

Remember, intense black marks created over time make it extremely difficult to remove and sometimes impossible. We refer to this as 'inground soil'.

There is one other similar mark to be worried about..
This is the black lines that go around all the edges of some carpets in rooms and even on stairs. Now this could indeed be venting marks (as per above) from a gap between the carpet and the skirting board, but usually this is not the case. It's normally down to the fact that most people use an upright vacuum cleaner and when using it, it's virtually impossible to get right up to the edge of the carpet because the vacuum cleaner has a plastic casing that normally bumps into the skirting. The brush underneath cannot therefore reach the last 4mm or 5mm and so this never gets sucked up. What happens then after a while is that this eventually goes blacker and blacker until it becomes really noticeable. At this point it is probably too late to remove it all as it is 'inground'. It isn't something a professional cleaning company can normally take care of either, due to tooling and the possibility of damaging the paintwork and even the edging of the carpet itself. The lesson here is to use a crevice tool on the vacuum EVERY time you use it - to prevent this from happening in the first place.