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Posted: Tue Apr 25, 2017 3:18 pm
by Hairs
Hi all. Have been working on my permeable paving project for quite some time now. I have finished digging and have arrived at 380mm. 250mm sub base, 50mm bedding 80mm concrete paver. I'm using Terram geotextile between subgrade and sub base and sub base and bedding material.
Do you think this will be enough for a solid build, or should I use a geo grid as well as the sub base will be an unbound aggregate.
I want to maximize my parking area paving up to edge of the drive way. There is an old wall foundation and a haunch supporting the drive way. Should I remove the foundation before I lay the sub base..?
On the other side I have a wall foundation which I was going to use to support the sub base and then run edging stones hunched to support the paver.
I know there is along way to go and not much building to speak off but I would like some feed back/help on the edging. Thank you in advance Hairs
Posted: Tue Apr 25, 2017 5:49 pm
by Tony McC
I definitely would NOT use a geo-membrane between sub-base and laying course. On commercial projects we know this can (sometimes) act as a slip membrane, enabling the paving and bed to 'slide' over the sub-base. The argument against that is that the restraining edges should contain any such slippage - but why put additional strain on the system?
A geo-grid can't make it any worse, but, for residential driveways, I often wonder whether it isn't just a bit of over-engineering. I've seen the data to show the geo-grids are very useful on commercial applications and do help minimise any settlement or drift, but I can't help thinking it's all a touch much for 2 cars a day. And if you're using a geomebrane at formation level, I'm not convinced a geo-grid is providing anything much on such a relatively small area.
The foundation you want to remove: is this the area of concrete shown projecting from the beneath therdriveway on the left in the first photie?
If so, you could actually pave straight over that, and allow the surface water to drain laterally into the larger area of permeable Type 3 sub-base.
Posted: Tue Apr 25, 2017 9:51 pm
by Hairs
Tony McC wrote:I definitely would NOT use a geo-membrane between sub-base and laying course. On commercial projects we know this can (sometimes) act as a slip membrane, enabling the paving and bed to 'slide' over the sub-base. The argument against that is that the restraining edges should contain any such slippage - but why put additional strain on the system?
A geo-grid can't make it any worse, but, for residential driveways, I often wonder whether it isn't just a bit of over-engineering. I've seen the data to show the geo-grids are very useful on commercial applications and do help minimise any settlement or drift, but I can't help thinking it's all a touch much for 2 cars a day. And if you're using a geomebrane at formation level, I'm not convinced a geo-grid is providing anything much on such a relatively small area.
The foundation you want to remove: is this the area of concrete shown projecting from the beneath therdriveway on the left in the first photie?
If so, you could actually pave straight over that, and allow the surface water to drain laterally into the larger area of permeable Type 3 sub-base.
Hi Tony great site and love the Book 
Ok will lose the geotextile in the upper layer.
Food for thought leaving the concrete foundation and using it as a run off for storm water back into permeable sub base. However I will still need remove the haunch to place a paver up to the edging.
Hi Tony great site and love the Book
Ok will lose the geotextile in the upper layer.
Food for thought leaving the concrete foundation and using it as a run off for storm water back into permeable sub base. However I will still need remove the haunch to place a paver up to the edging.