# Forum Home Renovation Paving  Haunching 101 - is this overkill?

## Karri

I got this nice pic from another post that wasn't specifically about haunching, so I thought to start a separate topic about haunching (or edge restraints). 
What do you think of this?   
I spoke to a paving contractor about edge restraints and it didn't sound anything like the above.  It was more like dig along with a trench shovel (about 100mm wide I suppose) then slap some mortar mix in there.  Which by my reckoning could be a quarter or less of the mass in the above pic. 
I think a ag:sand:cement ration of 3:2:1 would be a far better option than mortar. 
BTW - This is Perth's sandy soils. 
I've seen many failed driveway edges.  For example failed edge restraints (and sinking):   
What do others think - is the above 1st pic over kill?  I tend to think that it is a bit, but most haunchings would not be even close to that. 
Do you use concrete or mortar?  If concrete, what dimensions and mix is optimal without going overboard?  :Question:

----------


## Pulse

yep that is overkill, I do what the paving vontractor suggested.   
Sent from my iPhone using Tapatalk

----------


## PlatypusGardens

Not overkill at all. 
It's only 100mm deep - twice the thickness of a paver.
Driveways like the one pictured fail because of insufficient haunching.
Especially if it's curved and you're turning across it. 
I wouldn't skimp on it for the sake of a bit more concrete.
I've even seen people put reo in the mix when it's a curved driveway. 
No such thing as overkill when it comes to structural stuff and footings IMO.
At least you know it's gonna last.    :Smilie:

----------


## Marc

It all depends on the soil. On sandy soil it will fail regardless unless you dig it all up 300 deep and replace with blue metal, compact and then do your bit with as much concrete and reo as possible. On rocky soil of course you get away with less.

----------


## PlatypusGardens

When in doubt, double everything.    :Smilie:

----------


## METRIX

WOW, we have gone from 50mm to 100mm to 300mm, do I hear 600mm,  600, 600, anyone for 600, ok 500, speak now or 300 it will be  :Biggrin:

----------


## PlatypusGardens

> WOW, we have gone from 50mm to 100mm to 300mm, do I hear 600mm,  600, 600, anyone for 600, ok 500, speak now or 300 it will be

   *425* 
Final offer.  :Nonono:  
But you'd have to chuck in a couple of stubby coolers and a 3-pack of carpenter's pencils at least.
Maybe a bumper sticker as well.    :Driving:

----------


## METRIX

Your easily please, I would have given you a 12Pk of Pencils.

----------


## Pulse

we don't know if it is a driveway or sloping or subject to turning vehicles or how close cars will drive to the edge. If cars are actually driving on the edge the it is not overkill, pedestrian traffic only it is.  
Sent from my iPhone using Tapatalk

----------


## PlatypusGardens

> we don't know if it is a driveway or sloping or subject to turning vehicles or how close cars will drive to the edge. If cars are actually driving on the edge the it is not overkill, pedestrian traffic only it is.

  Well I was responding to instances like the photo in the first post.
It says failed driveway, it looks curved and it has failed due to insufficient haunching and base praparation. 
In a situation like that it's not the DRIVING OVER the edge that causes it.
Not even driving close to it.
It's the sideways force of vehicles turning, forcing the edge outwards.
Especially a larger 4x4 which generates a lot of sideways force.  
When living in Perth I saw so many driveways like that.
Some of them had less than 50x50mm edge haunching.
And just mortar mix as well.
Even saw some that had been done with rapid set and (by the looks of it) hosed in.   
Overkill is always better.   :Smilie:

----------


## ErrolFlynn

> 

   I'm particularly interested in this because I'll be doing some paving shortly (driveway that runs next to a neighbuour's fence). So, what do you presume the different levels to be? Would I be right is supposing: 
Bedding = sand
Sub-base = not sure but maybe road base material or some sort of gravelly stuff that can be compacted
Sub-grade = presumably ground level (whatever that might be) - natural soil level

----------


## phild01

I thought for a driveway that reinforced concrete under all the paving would be the way to go.  Had this done long ago by a paver friend and still perfect.

----------


## ErrolFlynn

No drainage = mould

----------


## phild01

> No drainage = mould

  It was on a slope and gets good sun.  Do you mean moss?

----------


## Karri

> Would I be right is supposing: 
> Bedding = sand
> Sub-base = not sure but maybe road base material or some sort of gravelly stuff that can be compacted
> Sub-grade = presumably ground level (whatever that might be) - natural soil level

   Yes on all counts.
Bedding = sand, about 25-40mm and should be clean concreting or plasterers sand, not brickies sand with clay in it, else you may get efflorescence.
Sub-base = limestone, fine gravel, or the actual stuff called "road base" from landscape yards.

----------


## Karri

This Midland brick brochure has excellent specs on the edge restraints, including diagrams, and mentions that MPA 20 concrete should be used.  *MIDLAND BRICK CROSSOVER PAVING GUIDE*
Page 3 says this:  

> Alternatively, an edge restraint barrier can be installed
> using pre-mixed concrete (20:14) i.e *20 mpa*, 14mm
> aggregate size or a site-mixed equivalent. This barrier
> must extend under the brick approximately 100mm to a
> depth of 100mm and should extend beyond the header
> course approximately 100mm. Finished barrier must ﬁnish
> approximately 20mm up from bottom of header course,thus creating a lip (refer ﬁgure 5).

  Basically 200mm wide by 100mm high. 
To achieve approx 20 mpa concrete with a cement mixer at home, what ratios or bluemetal, sand and cement would be needed?

----------


## Karri

> I thought for a driveway that reinforced concrete under all the paving would be the way to go.  Had this done long ago by a paver friend and still perfect.

  Sounds solid, but in Perth I have never heard of this.  On the coastal plain, our sand is just clean quartz.  So my opinion is that as long as this quartz sand is compacted well, and you have *GOOD* edge restraints, the paving should last for at least 20+ yrs.

----------


## PlatypusGardens

So.....what happened here in the end?

----------


## Karri

If you mean the example pic of failed edge restraints, well that neighbours driveway still looks the same.  It's been like that for a couple of years.  I just used is as a good example to discuss.

----------


## PlatypusGardens

Yeh I realise that wasn't your place. 
But you were talking about paving at your house and I thought this thread was about your job as well.
Has there been any progress there?   :Smilie:

----------


## ringtail

Surely all of this is telling everyone to forget paving and just concrete the driveway. Stencil it if desired.

----------


## PlatypusGardens

...or do things properly   :Wink:

----------


## Karri

> about your job as well.
> Has there been any progress there?

  Yeah, going ahead with ours - FINALLY!  I have stressed compaction and the edge restraints aspect with the paving contractor a number of times.  He is planing to use 20/10 concrete.  10mm ag looks a bit small, but better than plain mortar any day.

----------

