The Brew Cabin

Posted: **Mon Apr 17, 2006 2:16 pm**

About mid-November, we got our driveway re-tarmaced (190 sq metres). The work was done by a reputable local firm, but as a 'homer' in the knowledge of the firm's owners. They dug out what they thought were the bad areas, filled them in then tarmaced the whole drive (had all the right looking equipment e.g. rollers !)
Problem is that we have just returned from 3 weeks holiday to find about half a dozen tarmac 'molehills'. Some have weeds sticking through them, so I assume this is the cause, but we never had a problem with weeds on our old driveway.
Can anyone shed some light onto, as we will be calling them on Monday to complain and a bit of knowledge would help:

1) the exact cause
2) is this easily fixed, or will they appear everywhere over time
3) any advice on what I should be asking/insisting on from the contractor

Thanks

Posted: **Wed Apr 19, 2006 10:08 am**

They must be a particularly aggressive weed to force their way through 5-month old bitmac - Jap Knotweed perhaps? If so, there's nowt you can do. The contractor could have laid a geotextile to defelect the weeds, but they would have surfaced at the edge of the membrane, regardless.

I can't say whether the weeds can be eliminated or not as we don't know what type of weed is involved. As I said, if it's Jap Knotweed, you're stuffed, but if it's Dock, Dandelions or Equisetum (Mare's Tails), a good dose or three of sodium chlorate usually gets shut of the problem.

If the weeds were obvious before the contractor commenced work, then they should have amended their design accordingly. If there was no trace of these weeds previously, there are two possible causes: the excavation exposed seeds/rhizomes or some other buried part of the plant that was then able to re-grow; or the contractor brought in the weed with imported material.

The first thing you need to do is identify the weed.

The Brew Cabin

Tarmac problem - 'molehills on my drive'