[jacko]

Hi Guys

Pics below are in a bowls clubhouse with lots of sun exposure through large windows.
Carpet been down 4 years - after 2 years those white marks started to appear.

Carpet supplier did not want to know.

No transfer from the marks at all. White marks even more prominent UNDERNEATH door mats!

The marks were NOT made by feet.

No point in cleaning as marks are irreversable.

Carpet is attached to concrete floor with adhesive.

Any idea what has happened here?

My theory is that the heat has reacted with the adhesive somehow.
(I used a hair drier on a patch and it started to turn white slightly - but not sticky)!

Will be very interested in your thoughts.....

cheers

[clinton]

Jacko

Try and find a post by roger dr carpet about 5 weeks ago and it looks like the similar problem.

Was even said its the concrete dust coming up from the carpet

[M.Acorn]

I see something similar in an office i do,the concerete floor underneath is not completly flat,the raised bits are all covered in dirt and dust where my hoover does not pick up ! not sure if it`s the case here though ?

[Doug Holloway]

Hi Guys

Looks like UV damage to me, I suspect there was a problem with the pigment during manufacture or something, possibly high alkalinity from the substrate has destabilised the pigment and left it more vulnerable to UV.

Irreversible.

Cheers

Doug

[jacko]

No Mark, there is no transfer of dust or soil, it is definately colour change.

[John Kelly]

Jacko, have you got down on the floor and looked at the profile of the carpet? As Mark has said those white bits may be slightly raised either due to an uneven floor slab or uneven adhesive. This would cause the pile to wear more quickly on the raised areas especially when vacuuming. This wear can remove the colour or it could be the backing showing through. Under the mats could be the same problem due to friction.

[jacko]

Doug, thanks for that but how does that explain complete whitening under doormats ?

[wmidsgw]

Hi

Although I believe Doug may be correct saying it could be a problem with the pigment during manufacture,  could there be a remote possibility that their 'own  insitu cleaners' have been spotting areas of carpet periodically using a bleach based product. Now this may seem improbable, but I've certainly come across similar over the years.  If it has been going on, then it would be a gradual transition to the present situation they now find themselves in. I would certainly ask this question of the staff there so you can eliminate this possibility. Other than that, I would guess a manufacturing fault.

Gordon

[kerrpmiddleton]

looking at the pic s  i recon that the bolwers are draging in fertilizer in of there feet , which in due course is causing chemical reaction, remember these fertilizers are very high in sodium& nitrates,

[Doug Holloway]

HI Guys

Jacko, didn't see the bit about the mats.

I suspect the mat has concentrated the alkaline effect and therefore destabilised the pigment even more.

Cheers

Doug

[Dave_Lee]

Could it not be a simple case of general cleaner using a product containing a bleach over a period of time to remove stuborn marks. Maybe having done the worst part by the door before doormat was placed there.
Dave.