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Wet or dry sand?

Glazenwasser (.NL)

Active member
Messages
101
Location
Netherlands
Hi guys... I have been looking into why we do what we do and why.

Now we buy kds at prices between 4 and 6 a bag...when a normal bag of the same type and weight will cost say 2..... we pw then wait days for the ground and slabs, bricks, tiles to dry....

Now looking at slurry, we pour that wet....why not clean a drive and when finished .... layout the sand and flood the area and broom in the sand.

I was talking with a retired career road layer the other day and he told me this used to be how they did driveway refurbs years ago here in The Netherlands.

I have a patio and driveway here and the stones I have are 200mmx40mm and the gaps are about 5mm average and the depth of gap is 30mm approx.

I have tried this method both with kds, it's normal damp type coarser sand grit combo ... so kds laid in dry as per normal after allowing for drying out, also laying in sand straight after cleaning without waiting for drying.

Conclusion from this?.... same same.

So if indeed it's all the same....why clean then return 2,3 days or longer to sand with expensive sand when you can finish the same day...Job and knock?

Without wanting to sound like a complete d#$% would prefer to hear about actual experiences, you never know we could all be making more cash for the same job just by doing things differently i.e no expensive kds, no returning to customers house etc,etc

Cheers Dave.

 
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If the ground is wet the sand doesn’t flow over the surface it sticks to it , it also won’t fill the gaps but sticks to the sides and then when it does dry out it dropped down , that’s what I have found anyway . 

 
I just think nothing looks better than brushing in dry sand on a hot sunny day. Then I take my blower and blow all the loose sand away. The client is paying to have their driveway or patio cleaned so you want to make it look its best. I wouldn't be happy someone brushing wet sand about as I want instant results. I'm PW a patio and driveway today. Have fitted swivels to my lances and have bought a small whirlaway, will give an update later today. I will sand the driveway when the temp gets up, I have two to do and usually bunch them all together and wait for sunny day.

 
Just to be clear were not talking about some sand that's a bit damp or a little clumpy....were talking about dumping the sand out of the bag and then treating it like a slurry mix I.e plenty of water.

If the sand is now in solution why wouldn't it 'fall' into the gaps well?.  As we are all aware imagine you cleaned a drive 3 weeks ago, when exactly would it have dry 'enough' to resend?

I have also seen patio guys in the US doing the self same thing.

Cheers Dave.

 
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Depending how the patio was laid if it’s on a cement base the water will gradually evaporate and sand level drop you cannot just fill with sand if it’s a slurry , if it was a cement slurry then it would set ok .

 
@Glazenwasser (.NL) are you sure you aren't getting mixed up with something similar to what @Dave B put up a link in your other post, which is some times described as setting sand which looks like sand but sets after having water been poured over it like this Sika Sand

The stuff @Dave B linked is a resin type product which looks very much like a wet sand when poured out of the tub and sets hard. 

 
Hi Iron Giant.... I get your drift.... I have used polymeric type products where you pour out bags of 'dry product' sweep it in and then dampen the surface and the product then sets similar to Gator XP.

I am looking at the resanding of patios, drives and the like.... instead of waiting for the ground/slabs to dry out before gently sweeping in kds, you after cleaning bag out sand and then use water to aid the filling of sand into the gaps similar to how 'slurry type grouts' are installed such as gftx, rompox.

Years ago this is how alot of sand was set into slabs etc here in The Netherlands.

Even today a type of sand called 'brekker' sand is used alot today for stone/block paths, drives, patios.....The sand (not kiln dried) is swept in and then wet down, the sand left on the surface is left to work it's way into the surface 'over time'.

Granted if I were to buy DIY shed bag sand which is as we all know is generally damp and clumpy and threw that around and tried sweeping I  would just clump look good for about 2 hours and then start to fall leaving gaps and holes depending on the underlying sand base.

The pic below is the pad is the front of my house, the tile/stone are a old Dutch type in a group called 'Klinkers', these are 200mmx40mm the gaps were avg of 5mm wide 30mm deep. The sand is DIY shed cheap 'Brekker'  sand..... poured out, swept in with a broom and a hose with a gentle setting sprayer setting. Slab was 25 years old, pressure washed.

15831665749764850178808884918695.jpg

 
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You might be describing EasyJoint which you add water and brush into newly laid Indian Sandstone slabs. Its like little silicon beads that expand with the water and don't leave any staining on the slabs.

 
Hi Iron Giant.... I get your drift.... I have used polymeric type products where you pour out bags of 'dry product' sweep it in and then dampen the surface and the product then sets similar to Gator XP.

I am looking at the resanding of patios, drives and the like.... instead of waiting for the ground/slabs to dry out before gently sweeping in kds, you after cleaning bag out sand and then use water to aid the filling of sand into the gaps similar to how 'slurry type grouts' are installed such as gftx, rompox.

Years ago this is how alot of sand was set into slabs etc here in The Netherlands.

Even today a type of sand called 'brekker' sand is used alot today for stone/block paths, drives, patios.....The sand (not kiln dried) is swept in and then wet down, the sand left on the surface is left to work it's way into the surface 'over time'.

Granted if I were to buy DIY shed bag sand which is as we all know is generally damp and clumpy and threw that around and tried sweeping I  would just clump look good for about 2 hours and then start to fall leaving gaps and holes depending on the underlying sand base.

The pic below is the pad is the front of my house, the tile/stone are a old Dutch type in a group called 'Klinkers', these are 200mmx40mm the gaps were avg of 5mm wide 30mm deep. The sand is DIY shed cheap 'Brekker'  sand..... poured out, swept in with a broom and a hose with a gentle setting sprayer setting. Slab was 25 years old, pressure washed.

View attachment 19515
The sand you are using there is a lot coarser than what we would use on block paying , yours looks more like grit .

 
Hi Pjj ,Yes this is a common block paver sand called 'brekerzand' it's much coarser than kds type sand and contains grit and come as it comes and it generally a little damp from builder merchants or diy sheds.

Here is a link to a Dutch company that do all sorts of paving, laying gear, they even have a machine to wet sand.




 
7 minutes ago, Glazenwasser (.NL) said:

Hi Pjj ,Yes this is a common block paver sand called 'brekerzand' it's much coarser than kds type sand and contains grit and come as it comes and it generally a little damp from builder merchants or diy sheds.

Here is a link to a Dutch company that do all sorts of paving, laying gear, they even have a machine to wet sand.


Very interesting video I have never seen anything like that it’s a huge machine , looks a right faff and seams to create a right mess how do you get rid of all the wet sand that’s not needed ,? It Also  appears to leave a dirty surface on the pavers ?. I think I will stick to kds with a broom easier and quicker unless you are doing a supermarket car park . 

 
Very interesting video I have never seen anything like that it’s a huge machine , looks a right faff and seams to create a right mess how do you get rid of all the wet sand that’s not needed ,? It Also  appears to leave a dirty surface on the pavers ?. I think I will stick to kds with a broom easier and quicker unless you are doing a supermarket car park . 
Yeah that machine is big.... but all it is a broom, sand and water.... I have just spoken with a paver company in the US and they wet sand all the time...they clean the pavers, drive, patio wash down, then wet sand.... finished in one day no returning after unknown days of good weather.

Like I said at the start of this.... just trying to find a way to work smarter when I can.

 
Yeah that machine is big.... but all it is a broom, sand and water.... I have just spoken with a paver company in the US and they wet sand all the time...they clean the pavers, drive, patio wash down, then wet sand.... finished in one day no returning after unknown days of good weather.

Like I said at the start of this.... just trying to find a way to work smarter when I can.
Ime not criticising what you are saying I like the idear of sanding the same day but if it’s wet when you put the sand down surely you cannot get the pavers clean there will be dirty dust in the sand slurry that will leave the pavers looking dirty ?..  

 
Glazen...have you ever tried to shake salt out of a salt seller which has been outdoors in damp weather or in a kitchen which has poor ventilation? Net effect the salt granules inside the seller clump together and will NOT shake out of the tiny holes in the top no matter how hard you hammer on it; ?  Often found in outside cafes/pubs etc...

So... here in the UK, our block paving has a few mm gap much closer than your joints in your pic...if the ground is damp or even the weather is humid/damp the sand will not trickle FULLY into the gaps and fill them from the bottom up to the surface....It MIGHT enter the first few mm of the gap but being damp - it clumps up in the top of the 'crack' - so it looks like it's filled the gap...BUT when the sand dries out it no longer clumps up and now it trickles to the bottom of the gap...which is maybe 20cm-30cm below the surface - and now you block paving has gaps all over the place...

image.png

 
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No name did you watch the probst video where the guy removes a tight fitted paver and surprise, surprise the wet applied sand was fully seated in the gaps. 20 to 30cm deep gap? That's going to be alot of sand? now the salt shaker ..... fill it full of water, now all the salt is suspended in solution and will freely move to where its directed just like window cleaning.

I'm not trying to upset the apple cart but it's clear that here in Europe it is a method than may be used, even Tony from pavingexpert.com has stated it's a process that works with well draining sub base but just not used by many in the UK.

Many US companies wet sand after pw some seal as well some dont.

Possibly sand companies love the idea of selling kds at 6 a bag instead of 2.

The common sand for drives here and in many places is a grit/sand mix called 'brekerzand' and it's used everywhere here be it drives, patios etc.

Of course many patios and more 'pretty' locations use a finer sand similar to kds without grit but for aesthetic reasons plus people dont want to have people walking grit/sand into there houses.

All I'm saying is, having more than one string to your bow is the way to be...imagine in the last 6 weeks you cleaned 4 drives per week...when will be dry enough to resand 24 drives? Are you going to leave drives without the stability the sand provides for extended periods? Some stability is better than none at all. I'm sure the customer will have something to say when his drive now crumbles as they have driven over it without that stability. In this day and age of  ''I'll sue you', leaving drives sandless is a sure fire way to have your a#$% handed to you on a plate by some lawyer wanting a new Tesla.

One small claim will financially crush many sole traders even with disclaimers, hungry lawyers may find holes and who has the money in the first place to have bullet proof contracts drawn up?

Some have said they like the way the drive is left I.e nice sand lines, dust free surface. Now what happens when it lashes it down overnight?, rain drops from gutter overhangs, customer washes their car, their dogs wee on the sand lines... the surface will look like a complete mess....So if the main aim is just to make it look stunningly pretty for the exact moment you leave then should we all find a way to finish the job and ensure it remains that way for at least a season? Sealing? Slurry based grouts, polymeric sands.

We all will work the way we are comfortable with and that's cool, just be open minded and aware of what and why you/we are doing things the way we do.

Just like many things....give it a go, try for yourself....you may or may not be surprised.

The world was once flat and windows were cleaned with a shammy?

Cheers Dave.

 
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If the ground is wet the sand doesn’t flow over the surface it sticks to it , it also won’t fill the gaps but sticks to the sides and then when it does dry out it dropped down , that’s what I have found anyway . 
But the process is the have sufficient water to allow free movement of the sand. Try it see what floats so to speak? do a drive or patio...select a small patch do say 2m sq if you are returning anyway to resand it nothing to lose right?

 
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This was wet sanded 3 weeks ago and just like uk we have had plenty of rain...none of this area has dropped and this was laid around 15 years ago.

One thing to do is recheck some of your work that you have done say since November last year, what are they looking like?

Yes I much prefer to walk out in my shorts mid July dump some kds out and gently get a tan whilst the bikini clad 25 year old yummy mummy house owner mops my brow of sweat and asks if I would 'do her back with tanning oil's but the reality is always a little different ?

15832234163618900643070579361433.jpg

 
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Glazen...just watched the vid and can understand why that set up would work..would make sense on large scale work as shown...you're not relying on gravity but forcing the sand down into the gaps with the broom heads and water mobilising the sand - innovative. How you clean up all the 'waste' wet sand left on the surface - I would have thought that would be quite a task, no?

Looks like it's not without some risk...

http://www.pavingexpert.com/jointing10.htm"This 'wet jointing' relies on the laying course, and the other sub-layers, being exceptionally free-draining. Should the bedding, for example, retain wash-in water for a period of time, it may result in liquefaction and subsequent movement or settlement of the paving"

Three important points to note:

...the sand used is specially selected

the surface must be dry

Building sand, playpit sand, beach or river sand, grit, coarse, bedding, soft and plastering sands are not normally suitable. The sand to be used consists of grains that fall within an upper and lower size range, to ensure maximum interlock between grains.

The table opposite is taken from Table D4 in BS7533:part 3 and gives the grain size limits, but you'll be relieved to know that the aggregate companies have very kindly done all the sieving and sorting on your behalf, used a kiln to thoroughly dry the sands that pass muster, and then packed the results into convenient, if pricey, 25Kg polythene sacks, which are obtainable from most Builder's Merchants for £3 - £5 per bag.  

A kiln-dried silica sand, designed for this purpose, is available from most builders' and civils merchants. This is a selected sand, very clean, and of certain grain sizes that work to increase the 'friction' between each brick or block. A specific grading envelope for this sand is given in Table D4 of BS7533:part 3.

Building sand, play sand, soft sand, grit sand or any other form of sand is NOT acceptable: it will fail and result in a rutted pavement. Don't spoil the ship for a ha'porth of tar!" (not my words btw)

The only downside I experience is on occasion is having to return a few days later (post clean) to resand - never really caused me any issues/lost time - usually only takes a couple of hours if that (I just rejig my schedule or fit it in over the weekend if needed)  Let us know how you get on!

 
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That's awesome info.... been delving into that alot myself. I his book....So much info in it!

Perhaps being here in .nl most things are below sea-level most building installations be it houses or drives are built with the conditions in mind I.e lowland and prone to flooding.

When these Dutchies need a little more land for housing ....they just make it !?

 
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