Paving project in france - advice needed

[canne_man]

I'm in the middle of a 150m2 paving project in France. I've been following the advice on this site avidly.

So far so good. Laid Drainage and terraces the drive, compacted etc. I made a few deviations from your recommendations. I laid Geotexile barrier between the sub base and the sand bedding layer, as I saw all the French paving sites I browsed, advise to do it this way. I have a clay sub grade and it is very compacted; Had it rolled once with a 2 tonne sit-on roller and again with 650Kg power roller, so I'm mainly worried about sand washing down into sub-base and not the subgrade being undermined. Intially it was a bit loose. although I did add extra grit sand to fill the voids and whack down before laying the geotextile. The 150 euros it cost wasn't expensive compared to the 3500 euros for the pavers, so why not over engineer a little ?

So now for my real questions.

Q1
I'm using a 12x12x6 square concrete paver, which is has been finished to make to look old, byy chiping and rounding the edges, What this does however means that the fit between others is a bit looser and boy do they drain well. Even with torrential rail all the water sinks into my sub-base and my expensively laid drainage system is somewhat underutilised. As the joints are a little bigger can I get away with normal fine sand as long as it's dry for jointing. At my local French builders yard, which stocks everything you can imagine, they didn't seen to stock jointing sand. They told me to use Sable de Biot, which is the fine grade yellow sand. I did find a link at another builder merchants However.

French Jointing Sand ?

This is polymer sand and apparently you put it down dry, and then hose it down well. I which point it sets hard and self seals, preventing the sand from being washed away. Does this sound like right product ? In which case I wouldn't need to also use a joint sealant.

Q2
I have one section I need to pave which is at a 30degree angle. It's only a 1m2 area. Should I concrete the pavers down over this area.

Q3
I haven't used an edge course for much of the borders as I have dry stone walls which border the paved area. The trouble is that edge is not dead straight as the stones are irregular shapes as they butt up against the paving. This means that some gaps as much as 5cm are present. I was thinking about using a dry mix (sand,cement, colour) and adding this to fill the gaps. Then filling all other joints with with fine sand. In this way after whacking down the holes would be filled and the mortar would set. Is there a better option ? I'm worried that the paving could become bit loose and push into these gaps at the edges

Q4
My blocks already have quite alot of chips, but I don't want to add too many more. When I whack the pavers down, I was therefore wanting to use a sole, can I improvise with a bit of old foam back carpet taped in place ?

[Tony McC]

You copied the French? Remind me: how many times have they been overrun in, say, the last 100 years? And how many times has this ignominy been endured by Britain?

For standard constructions, a membrane between laying coarse and sub-base is a waste of money (Pounds or Euros). You'd have been better off spending 150 Euros on tightening the surface of the sub-base. The only time I would recommend using a membrane between sub-base and laying course is when an open-textured sub-base has been used, ie, as with a permeable paving system.

Q1 - jointing sand. I have a distruct for the promotion of polymer sands for jointing block paving. My cynical nature tells me that these products are being pushed in the interest of increased profits rather than a genuine structural need. If there was a big problem with scour or some other reason why the jointing sand was being lost, then I might consider using such a product, but I would not use one without justification. I laid block pavements for over 25 years and the standard kiln-dried jointing sand worked fine for me. If it ain't broke: don't fix it.

Q2 - 30° to the horizontal? As long as there are properly restrained edge courses in place, there's no need to lay onto concrete.

Q3 - When working against uneven walls, it really is best to use an edge course. Not only does an edge courses give you a certain, straight and stable edge, it makes the cutting-in so much easier. Any gaps between edge course and walling would be filled with a concrete or coloured mortar, as you describe, so your ide is basically sound, but you've not half made life awkward for yourself.

Q4 - foam-backed carpet willl probably disintegrate witthin a couple of minutes. The carpet bit is fine: it's that shitty foam stuff on the back that falls apart! If you've any of that membrane left over, then 3 or 4 thicknesses of that lashed around the plate will do the trick.

[canne_man]

Thanks for the info. The finished result is looking pretty good.
Living in France has taught lots about design side of things; for the better I think.
But when it comes to doing things properly it's a complete nightmare, you may think their are lots of cowboys in the UK, In france (Cote D'azur) I calaculate that 50% fall in this category. So I've been force to do things myself so I can get done to the right standard. Thank goodness for your website.

So at least the geotextile won't hurt. As for polymeric sand I agree with you, a bit of a rip off.
Although after being inspired by sucessful 150m2 paving success. I'm thinking of redoing the Pool Patio in block pavers.

It's done in crazy paving which is cemented down and it keeps cracking. I have clay soil and it moves lots, partially down the fact that we get long hot summers and cold winters, so theres lots of expansion to deal with.
As an ideal solution I was thinking that block paving would do the trick nicely. Trouble is that paving by the pool means folks with bare feet and lots of water splashing around. I was therefore thinking that for such a block paving application polymeric sand would be good. Still allowing expansion but not getting eroding by an intensive application such as a pool deck.

Any feedback is much appreciated.

-ain

[Tony McC]

Around the pool area, rather than rely on a polymeric, I'd opt for a 'standard' KD sand and then use a good quality sealant. A good 'trick' to use around pools is to sprinkle a small quantity of the KD sand onto the still-wet surface of the freshly-applied sealant, as this will help improve traction.