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Posted: Thu May 29, 2008 5:46 pm
by E9B6
About two years ago I had a drive laid with brown bitmac 40mm thick

Within the last year I have a dalmation finish - there are black spots everywhere (between 25mm and 50mm). Not on the concrete surround, not on the patio, only on the bitmac.

I have pictures - only I haven't sussed out how to upload them

Posted: Thu May 29, 2008 9:31 pm
by bobbi o
need the pic

Posted: Fri May 30, 2008 3:05 am
by matt h
seems like some form of algae..blackspot,need photos have look at main site may help:(

Posted: Fri May 30, 2008 9:50 am
by E9B6
How do I upload a picture? - it is on my own PC - not hosted anywhere, but the image button requests an http:// url

Posted: Fri May 30, 2008 5:09 pm
by Rich H

Posted: Tue Jun 03, 2008 11:18 am
by E9B6
This is a picture of the black marks - they cover the entire area of bitmac and are about 25/50mm in diameter.

Image

Posted: Tue Jun 03, 2008 12:52 pm
by bobbi o
never seen that before,could it be the couloured binder has worn off and exposed the natural colour of the aggregate,before it was coated?

Posted: Tue Jun 03, 2008 7:33 pm
by Dave_L
Looks like oil drips to me.

Posted: Tue Jun 03, 2008 8:43 pm
by E9B6
Definitely not oil spots as it is common across areas where no vehicles can access.,

Posted: Tue Jun 03, 2008 9:22 pm
by Dave_L
Is this staining over the entire surface?

Very odd. Looks just like oil drip stains (I sadly have a couple on my newish red tarmac driveway and they bug the crap out me!!!)

Posted: Tue Jun 03, 2008 10:35 pm
by E9B6
Yes - over the entire surface and as I said also in areas where vehicles cannot access.

Posted: Thu Jun 05, 2008 12:41 am
by matt h
have you sprayed any fertiliser nearby? does look a bit 0dd:(

Posted: Thu Jun 05, 2008 7:54 am
by E9B6
No fertiliser sprayed, the drive hasn't even been washed down.

Posted: Thu Jun 05, 2008 3:47 pm
by TarmacLady
I'm at a bit of a handicap, as I can't see the piccie no matter
what I do (I can't even see it when I point my browser to imageshack!)

BUT...might this be something in the tarmac itself? The brown colour indicates to me that there's a fair amount of coal tar in the mix.

If asphalt/bitmac were mixed in with it, you'd have a bit of a mess, as the two don't mix together. Might the spots be globules of asphalt/bitmac that have made their way to the surface and spread?

Even if it's not primarily coal tar, the chance still exists that they've not melted and/or mixed the asphalt correctly.

Think the little globules of oil that rise to the top of your salad dressing.

Correct me if I'm wrong -- as I said, I can't view the piccie, but I remember coming across issues like this.

Posted: Fri Jun 06, 2008 6:23 pm
by TarmacLady
Ooh. Don't know what's changed, but now I can see the photo. Definitely not blobs of unmelted asphalt.

Is your drive in a sunny area, or is it well-shaded? It almost looks like mould or mildew.