Sand coming to the surface problem

[loudog]

Hi to all, I done a clay paver job about 4 months ago and hes rang me to say that when it rains it bring the sand up and he has to go out and sweep it off, cant hink myself why nut you guys might know why, i did do one thing when i layed it which i dont normally do, and that was i layed the membrane under the type one and on top the type one ( this is was the client wanted i told him it wasnt necessary but they think you are trying to get out of it. do you think this could be the reason, your help would be very welcome.
cheers guys

[Suggers]

What type of membrane?

[loudog]

hi, i buy it at a place but there is no name on it, its a geo tex one which lets the water through not a plastic sheet, and its not one of those cloth ones that gardeners use, sorry not much help.

[mcelec]

hi, i have used concrete pavers from marshalls and im having a similar problem, whenever it rains the sand seems to come from the joints and when the paving has dried it is necessary to brush of the excess sand!

i have also laid a geo textile between the sub base and the bedding layer (i got it from wickes its labled driveway fabric)


is this something to be concerned about? will it stop with time or will i have to constantly top up the joint sand? would applying a sealent prevent this?wickes driveway fabric

[msh paving]

laying geotextile under bedding sand layer does not good at all,that wicks stuff is nothing near as good as terram or lotrack 1m wide rolls need to much lap gives a working with of 800mm,

the geo textile might be causing water to collect under the sand layer if it is a dense fabric

it might stop in time once the surface of the joint get dirt in them, MSH

[Bob_A]

Take your point about the 800mm bit but was I lead to believe that the Wickes stuff was ok and a lot better than a lot of the other stuff that gets passed off as driveway fabric.
It's a grey colour feels quite dense and has a sort of fibre look about it, possibly it may take time for moisture pass through it, not like that black weed suppressent stuff.

Any other comments on the Wickes stuff would be appreciated. It's easy to get and seems good value at the moment with it being on special offer at half price, or is that not the case!
Was thinking of getting some myself but now I have doubts.

[Bob_A]

Just read my last post again and was a bit worried that it came across I was doubting MSH. That's not the case I'm just trying to clear up some doubts in my mind.
Is the problerm with Wickes Driveway fabric that it's only 1metre wide or is it the actual make up and quality of the material?
I was thinking that many people like myself would be considering buying the Wickes stuff while it's on half price special offer. Not so much to use between sub base & bedding layer but between sub-grade & sub-base.

[mcelec]

im still having a problem with this eveytime it rains, when the paving drys it is neccessary to brush off the excess sand from the top of the pavers? the joints all still appear full?

is this cause for concern has anyone ever had this happen? and will it cease with time?

[Dave_L]

Wait for hot and dry weather and seal the blocks - this also stabilises the jointing sand.

[colordrives]

This always happens on a new block paved driveway when it is subjected to heavy rain, as the rain basically blasts it out the joints, given time the sand will solidify and the problem will stop happening, granted sealing will prevent it but it can be an expensive solution if a decent sealant is used.

[worldofpaving]

As Colordrives says this often happens on new installations, basically because the joints are totally full of sand - when the rain hits, the sand "bulks" (sand does not absorb water as such) so there is not enough space in the joint for all of the bulked sand.

On older installations the joints have lost some sand and settled.

I agree that sealing prevents the ingress of water into the joints and also binds the sand thus solving the problem but I wouldn't agree that it is expensive - a 25L can can be purchased on the net for around £70 so that's about a £1 per square metre, doesn't seem much to finish off and protect 3 or 4 grands worth of paving.

Best,
WOP

[colordrives]

WOP your suggesting that 25L of sealant would cover 70m with 2 coats? what sealant is that then?

Resiblock for example is more like 3L per m 1st coat , 6L per m 2nd coat which means that's 25L will cover only 8.3m on the first coat. so I repeat, it can be pricey.

[worldofpaving]

It's a bit difficult as an exhibition organiser to play favourites so I try not to name specific products, however there are a number that come to mind that would achieve 70 metres, I will have to let them pick up on this thread if they are out there.

There will, of course, be some variation in porosity between differing grades and qualities of block paving, but having been involved in driveway sealing in the past, even if one were to use a can and a half on a less dense block, I still think it's a reasonable price given the benefits that come with sealing over and above the stabilisation of joints.

Best,
WOP

[msh paving]

there alot off other sealers around,but make shure you you don't chose a pattern inprint concrete sealer to use on block paving,as they are not compatable ,having said about sealer its a big move to seal a driveway let the sand settle and it will sort itself out,if need be use a "marshalls keybond" solution that just bond's the sand nothing else
MSH

[colordrives]

msh have you ever used marshalls keybond? is it any good ? how is it applied?