Gtfk vdw840+ starting to discolour/darken

[Rossoliver]

Hi,

I jointed my patio last summer with Gtfk VDW840+ and over winter it started to slightly darken and discolour - I'm not sure if this is some kind of algae growth or if it's just dirt that's washed over the patio and stained the jointing (my garden gets waterlogged so I often wash off muddy footprints). Pressure washing doesn't seem to shift it and i've tried a course of wet and forget without much luck - has anyone seen this before/successfully treated it? It's not particularly bad, but I would like to sort it out if it can be rectified or at least prevent it from getting any worse.

Many thanks,

-Ross

[mrpvs]

I can't really advise , but I used this stuff about a month ago .
It did the job great initially , but seems to be taking forever for the joints to dry out when it has rained , is your's like this ?

[lutonlagerlout]

its a polymeric so it gets dirty
all the polymerics suffer from this to one extent or another
a good clean can help but be careful with the jetwasher as you dont want to blow the stuff out
cheers LLL

[kiteboy]

Just bought this stuff - (the black stuff) hope it lasts - its not cheap!

[Rossoliver]

Ah, I figured it would just be getting dirty - the wet and forget doesn't seem to be doing the job (which is surprising as it worked wonders in my stone window sills); is a weak bleach mix and a stiff brush the way to go in terms of cleaning?

Mrpvs- yes mine is the same; it stays dark for quite a while after rain - especially around the corners of the slabs where joints meet... Oddly this is where the worst of the dirt staining seems to be too...

[StuartP]

These posts about using Wet and Forget are now quite old and wet and forget work slowly over time as it is not an acid or bleach etc.
Lichen can take many months to go. Have you had results since?

[Tony McC]

StuartP - if you have a commercial relationship with Wet'n'Forget, the T&C's of using the Brew Cabin require you to disclose that so we know where you're coming from.

I, too, have noticed that while Wet'n'Forget is amazing on the actual paving, it does seem to struggle to be quite as effective on permeable jointing materials, such as the VDW840, but also products such as EasyJoint, Nexus, FastPoint, 365 and the like.