I need to run a power cable under a tarmac drive. I am using 3 core armoured cable. I propose cutting a channel which I hope will be under 10cm, cut with a saw to get smooth edges and excavated by hand.
I had intended to patch this channel with cold bagged macadam. Will this be adequate? Do I need to use jointing compound along the edges?
Tarmac drive - channel repair - Repair channel made under drive
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Tony McC
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No great need for jointing compound on a residential driveway. It would make for a more competent repair, but it would also make the channel far more noticeable - you have to weigh-up aesthetics against longevity and decide which is more important to you.
The repair mac is the 'weak link': it is usually of such a poor quality that using a cold pour jointing compound with it is a waste.
The repair mac is the 'weak link': it is usually of such a poor quality that using a cold pour jointing compound with it is a waste.
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Is there another way to repair this narrow channel? Could I just fill it with bitumen and roll some granite chips into it?Tony McC wrote:No great need for jointing compound on a residential driveway. It would make for a more competent repair, but it would also make the channel far more noticeable - you have to weigh-up aesthetics against longevity and decide which is more important to you.
The repair mac is the 'weak link': it is usually of such a poor quality that using a cold pour jointing compound with it is a waste.
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Tony McC
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Repair mac is the simplest, but the best is if you spot a blacktop contractor working locally and cn scrouge a barrowful of hot macadam from them in exchange for a few beer vouchers.
The trouble with the repair mac is that, no matter how well you compact it at the time, it will settle once the cars had a few goes at it. When creating a fillet, as is often done at the leading edge of new driveways to accommodate a difference in level between the drive and the public footpath, a bit of settlement is neither here nor there, but when it's a channel across a driveway, it becomes the proverbial sore thumb.
The best solution is to backfill with mac to within, say, 10-15mm of the surface, compact as much as poss with a punnel or the head of a sledgehammer, then "blind" the compacted surface with a dusting of sand. Lay a 'top course' of extra repair mac over the dusting of sand, and compact that.
In a few months time, when it's all settled, you should be able to peel off the top course and lay a new one. By then, the 'base course' will have settled/compacted to refusal (or as near as dammit) and so the new top course of 12-20mm will have less potential to settle in the longer term.
The other option is to backfill with concrete to within 15mm, allow it to cure, prime it with tack coat or bitumen paint, and then top it off with the repair mac.
If you find, in 6 months or so, that you have a really noticeable strip running across the drive, then maybe a cover up product, such as 'BlackTop' from Watco would help rejuvenate the entire surface and make it all look as one.
The trouble with the repair mac is that, no matter how well you compact it at the time, it will settle once the cars had a few goes at it. When creating a fillet, as is often done at the leading edge of new driveways to accommodate a difference in level between the drive and the public footpath, a bit of settlement is neither here nor there, but when it's a channel across a driveway, it becomes the proverbial sore thumb.
The best solution is to backfill with mac to within, say, 10-15mm of the surface, compact as much as poss with a punnel or the head of a sledgehammer, then "blind" the compacted surface with a dusting of sand. Lay a 'top course' of extra repair mac over the dusting of sand, and compact that.
In a few months time, when it's all settled, you should be able to peel off the top course and lay a new one. By then, the 'base course' will have settled/compacted to refusal (or as near as dammit) and so the new top course of 12-20mm will have less potential to settle in the longer term.
The other option is to backfill with concrete to within 15mm, allow it to cure, prime it with tack coat or bitumen paint, and then top it off with the repair mac.
If you find, in 6 months or so, that you have a really noticeable strip running across the drive, then maybe a cover up product, such as 'BlackTop' from Watco would help rejuvenate the entire surface and make it all look as one.
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