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Posted: Mon Apr 24, 2006 7:05 pm
by Hobby builder
I have a 1960s 16m long tarmac drive, that appears to have been overcoated with a thin (10mm) top layer that is peeling off in a couple of places where oil has leaked. The tarmac underneath seems pretty sound.
I want to widen the drive by about 250mm (on one side) and have the whole lot resurfaced, and will get a company in to do this for me.
Can the drive be widened without digging up the existing sound tarmac, and if so what should a contractor be recommending to me in terms of things that need to be done?
I couldn't find that much on the site about laying tarmac on top of existing tarmac, and wondered what depth of new tarmac/bitmac is recommended? Or is this not appropriate?
Is the thin top layer going to be a problem, or can the damaged parts be cut out and sealed?
Posted: Mon Apr 24, 2006 10:17 pm
by Ross-Paving
Why don't you save yourself a lot of money and bother - widen the drive with three lines of lock block in stretcher bond layout, bedded onto concrete. Surely a better option than resurfacing the complete drive, if the original is as sound as you say it is.
Posted: Tue Apr 25, 2006 2:16 pm
by Hobby builder
I guess there are a lot of things I could do. What I am trying to determine is how best to widen the drive with bitmac, so that I know what questions to ask when I get contractors onsite to bid for the work, and can check that what they are recommending makes sense.
I'm beginning to doubt my previous assertion that the original tarmac is sound, as there are a couple of places where it seems to ridge slightly across the drive. The drive is on shrinkable clay 
If I want to do a proper job, how much of the surface do I need to remove to ge down to a layer that I can then widen as a solid base and lay tarmac on top of. Should I go down to the base course or sub base?
Posted: Tue Apr 25, 2006 2:51 pm
by Tony McC
To widen an existing bitmac drive, the best construction usually involves...
1 - Exacvate area of widening to depth of at least 150mm and with at least 200mm of spread.
2 - Lay edgings to new boundary
3 - Lay at least 100mm of quality sub-base material to extended area
4 - Lay at least 50mm of binder course to extended area bringing it level with existing surface
5 - apply at least 1 coat cationic bonding emulsiuon to existing bitmac surface after cleaning
6 - lay at least 25mm of new surface course bitmac to ENTIRE driveway; old and new, making the finished surface appear as one.
Of course, there are many other considerations: what about if the old bitmac is dodgy in places? What about drainage? What about if the sub-grade is soft?
The best option is to get at least three contractors to look at the work and have them explain their preferred methodology to you.
Posted: Wed Apr 26, 2006 5:01 pm
by Hobby builder
Hi Tony,
Thank you for your advice. I found your website by chance a few months ago, and am extremely impressed by the quantity and quality of information; I know a lot of people have commented on this already. Have you thought of writing a book?
I have another question I hope you can answer:
My driveway slopes down and round, but the land either side is level leading to raised banks at the end (sunken driveway). The reason why I want to widen the drive is that delivery lorries have cut into the bank leaving exposed vertical earth facings.
What materials would you suggest I look at to edge the drive, where they need to be 20mm high at one end and 400mm high at the other? I would like to use brick edgings, but can't figure out how best to arrange them to achieve a good looking profile. Do you have any advice on this?
Thanks,
David.
Posted: Thu Apr 27, 2006 11:25 am
by Tony McC
Book - due out any day now. Allegedly.
Driveway - difficult/impossible to say what would work bestr without seeing the site. Even a simple photo might be useful.
Posted: Thu Apr 27, 2006 1:33 pm
by danensis
Tony McC wrote:Book - due out any day now. Allegedly.
* * * Flying pig alert * * *
Posted: Fri Apr 28, 2006 4:45 pm
by Tony McC
* * * Flying pig alert * * *
I think that pig just dumped on me head!
I was told April 21st. Amazon have it as today, April 27th. No sign of said book, though. Maybe they meant April 2007...or 2008?