Get listed in the Spick and Span Directory

Carpet Cleaning Issues - Carpet construction, upholstery cleaning, stain removal, equipment, events, etc.

Strange pile direction

Posted by paul_moss (paul_moss), 13 December 2003
Came across a funny one today.
When Cleaning a large lounge carpet I came across 2 areas where the carpet seamed slightly higher than the rest of the carpet.The pile also went in a different direction.
At first I thought something was under the underlay causing the area to rise,but after checking I found the floor was flat.

When the extraction wand made a pass over it, it seemed to suck to the carpet more.

The carpet was a Blue thick pile 80/20 wool blend.

Has any body else experianced this before ?
Posted by Dynafoam (Dynafoam), 13 December 2003

What you encountered is called 'pile reversal' and is caused by the fact that when we walk the trailing foot rotates slightly, this is more pronounced when walking in a curve. this results in the pile being pushed towards the outside of the curve and with  continued useage becomes permanent .

Whilst this can occur in any type of 'piled' carpet  it is most commonly encountered in velvets and least commonly in axminsters. It often gives the appearance of watermarks when looking along a hallway.

When inspecting a carpet prior to cleaning it is adviseable to point this out to the customer and explain the cause, as on many plain carpets the reversal will give a different apparent colour and since the effect only occurs in traffic lanes, may be confused with inadiquate cleaning. On heavy Chinese rugs, pile reversal can give the rug a patchy appearance, which may be more noticeable when the fibres are clean and therefore more reflective.

A similar effect is the 'spin spot', for example at the top and bottom of stair, where the 'landing' foot often rotates through 90 degees.

Posted by paul_moss (paul_moss), 13 December 2003
John thanks for the detailed reply.
I did point it out to the customer and suspected it was pile reversal. I have never seen it as bad as this though.The carpet was a darker colour but seemed to be a lot higher.The biggest confusion was that both patches were very close together and near to the wall of the lounge that wasnt a traffic area.
I thought it was more of a manufacturing issue than pile reversal.

Also arnt blue carpets a pain to clean

Cheers  Paul
Posted by Dave_Lee (Dave_Lee), 13 December 2003
Pile reversal, water marking and shading (all same the  thing) are not a manufacturing fault (as recorded as a judgement in law, following a legal claim many years ago) and are of unknown cause and can occur anywhere in the carpet. It happens in most carpets but is more obvious in plain ones and is certainly more noticable following cleaning as the light is better reflected, thus highlighting shading problems.
Posted by Robert_O (Robert_O), 13 December 2003
Hi I thought that you might find this article of interest which appeared within the NCCA Newsletter on the subject of Shading/Pile Reversal.

The phenomenon of shading/pile reversal, why it occurs, and new industry developments designed to prevent the problem.

The carpet industry has been plagued for many years by the phenomenon known as shading (pile reversal). There have been various theory’s concerning the exact cause of this problem but no one specific explanation can be attributed to it cause.

Believed causes behind the phenomenon of shading are: Foot trafficking, Stresses and strains within the manufacture of carpet, Humidity, Air circulation, Electro magnetism and Static electricity.

Carpet manufacturers have commissioned and conducted numerous investigations into this bane of their industry,  that I for one I have found extremely enlightening.

Shading/Pile reversal is as most people within the industry know, where the pile fibres re-orient themselves to lay in opposing directions to the normal lay of the pile. The fibres will then alter in shade appearance due to the way in which the light reflects off of the sides, or tips of the fibres. If the light reflects off of the sides of the tufts this will become more light reflective and appear lighter in shade. If however the light reflects off of the tips of the fibres this is less reflective and hence will have a darker shade.

Shading/pile reversal may continue from fitted carpets on to loose laid rugs, and even over door bars onto totally different carpeting. This clearly supports the manufacturer’s claims that this problem is not purely attributed to any particular carpet, or manufacturing defect, but to other environmental influences relating to the premises.

Electro Magnetic forces believed to influence shading
Recent findings from investigations conducted by the carpet industry implicate electrical wiring and subsequent electro magnetic forces to be a major influence in erratic, unspecific shading.

Dowsing sticks used in ancient times, and recent times, to find underground water have been known to respond to shading prone areas. There is evidence to suggest that Pets are also found to have a liking or an attraction for these shading prone areas of increased electromagnetic fields. I too can confirm that clients have thought that it was in fact there pet that was causing the discolouration of shading, because this was their favourite spot.

A company called Euro Lab, claim to have an electro magnetic meter which gives a reading on a rooms susceptibility to shading. Investigations have also been conducted into fibres for carpet that could displace these electromagnetic forces to inhibit or prevent the occurrence of shading. In scientific analysis/ experiments, shading in carpets has actually been purposely re-created by utilising the effect of electro magnetic forces within carpet fibres.

I understand that there is a system called the Neutralec, which has been designed to prevent shading, in displacement of electro magnetic forces believed to influence the occurrence of shading. This however is not considered viable, as the consumer would not be expected to purchase this product on the off chance that their carpet may exhibit shading.

Rylux Carpets have pioneered an anti shading treatment/ process called the ‘Trutrac’ which actually guarantees their range of treated carpets will not exhibit shading. This is done by setting the pile lay at much more of an angle to prevent the possibility of the tufts compressing in any way other than the natural pile direction.

This all seems a little bit like crop circles, and X files material, but I feel that it is important for any one within the carpet industry to be kept abreast of these developments.

I would like to thank Hugh Wilson of the British Carpet Manufacturers Association, (BCMA) for his invaluable knowledge, help, and assistance given so freely in discussing these technical issues with me.


Robert Olifent   NCCA Member 315

Posted by paul_moss (paul_moss), 14 December 2003
Now thats what I call an answer.
Thanks very much for your time.
Now I have a much better understanding of pile reversal.

Regards  Paul

This page is a thread posted to the cleanitup forum at and archived here for reference. To jump to the archive index please follow this link.