The road from Helmshore to the Grane Road in Lancashire was top-dressed last summer, I think. But now the top dressing is all coming off and when you drive along there you can hear the stones splattering the wheel arches. It looks a mess; all patchy and there are piles of loose chippings building up everywhere. I understand that the top-dressing is stuck down with a bitumen emulsion, which needs to be formulated correctly for the conditions then allowed to dry, not just to cool down, so as to stick the stones down. Now it looks to me as if the wet weather earlier this winter has affected the emulsion and it has failed. The lower panels and valences of my car are convered in small tar blobs, which are a pain to remove with white spirit. These did not come from hot tar last summer, they appeared during the wet weather.

I’ve stopped driving along there but I bet local residents are furious, at least those who have worked out what’s happening. Am I right about the emulsion being affected by heavy rain if it’s not correctly mixed? Anybody know anything about the science of this?

Have you reported it to your local roads team so they can take a look?

Happened a lot in various places by me meaning they had to keep resurfacing until it was right.

Yes it’s a bit of a pain on the car but doesn’t affect the paint or arch linings in anyway, just means it requires some more cleaning. Have a look at Tardis to help remove it with less hassle.

I sympathise. Can I suggest WD40 as an excellent method of removing tar spots. Spray the area, let it sit for 10 mins and wash off. Works a treat.

Its not just Grane Road, Bacup Road through Stacksteads, Cog Lane in Burnley and the road to Sabden are all the same. I believe the contractor is being made to come back and redo it all.

Its a poor surfacing technique anyway, just papers over the underlying problems. Spent an hour on Saturday getting the tar off my car.
Rossendale Free Press

See Chapter 8 in the following document for some light bedtime reading if you want to learn more:

http://www.standardsforhighways.co.uk/dmrb/vol7/section5/hd3799.pdf

Perhaps Table 8.4 in particular might be of interest.

Its a poor surfacing technique anyway, just papers over the underlying problems. Spent an hour on Saturday getting the tar off my car.

This is where most councils go wrong as it definitely should not be used to paper over the cracks, that’s like painting your window frames after they are rotten, but unfortunately with the lack of money for spending on highways that’s what is happening.

Interesting – our estate was top dressed last year and it’s been coming up for the last 3-4 months.