advice on laying a slabbed driveway

[kilty55]

ello guya n gals im looking for advice on how to prep and lay slabs for a driveway.

i have an existing driveway which is laid on sand and its all over the place,this is what i was planning on doing to sort it but any advice on dos and donts is welcome

lift existing slabs which are laid on sand bed and seem pretty level but are now lying squint etc

hire a compacter and flatten the area down nice n hard for laying new slabs

i was gonna bed them down with sand and cement and sbr,this i thought would stop any movement you get from the weight of the van/car...if this is the way forward what mix would u advise?

we also would like to point the gaps with mortar to stop weeds etc,,if we are using a sandy coloured slab should we use snowcrete with a colour added to it or grey concrete and sand with a colour? any help appreciated

[Dave]

Bed the slabs on a 20% slump sharp sand and cement mix.... bed as you go working to a string line on the first row after sussing the falls and then follow suit on consecutive rows.. quite easy really.. just like wet bedding tiles..

Tip is do not have to thick or thin a bed.. around an inch is spot on..

[kilty55]

cheers dave,the drive is quite a slope upwards the slabs should be heavy enough even on a wet bed for them not to slip/move?

[doug boardley]

Hi Jamie, I'd dispense with the sand, dig out about 200+mm, put in a layer of consolidated 25 down mm hardcore ( about 75mm depth) then concrete at least 100mm depth

[Dave]

cheers dave,the drive is quite a slope upwards the slabs should be heavy enough even on a wet bed for them not to slip/move?

At 20% slump.. they ain't sliding anywhere.....

[kilty55]

Hi Jamie, I'd dispense with the sand, dig out about 200+mm, put in a layer of consolidated 25 down mm hardcore ( about 75mm depth) then concrete at least 100mm depth

were in middle of fencing the top of this area just now and putttin posts in the ground is really shale/stoney,,seems like a 20 mm layer of sand on top of this doug at mo so should i remove the sand thats there add hardcore and use the compacter to flatten it....the slope going up wd be w right night mare to concrete

[Scott]

Like all flooring prep, make sure the substrate is up to it!

I used to use 100mm of hardcore minimum, (MOT or Type1) as the base and wacker plate flat. Then the sharp cement mix.

[Scott]

You got that in while is was typing

[doug boardley]

didn't realise you were on a slope mate, maybe best not concrete then, but certainly get a good bed of whacked hard core down then bed your flags as Dave says. My concern with sand bedding is that it can wash away if it's on a slope and if it's getting van traffic the flags tend to "seesaw" with wheels going over them

[kilty55]

cheers lads,what about pointing with coloured mortar does any one know whats best ,,,is snowcrete the way forward for a sandy yellow y slab with a colour mixed throo it or shd i use standard cement

[kilty55]

most info im gettin of the net is suggesting a 3 to 1 mix for bedding is this right?

[Dave]

cheers lads,what about pointing with coloured mortar does any one know whats best ,,,is snowcrete the way forward for a sandy yellow y slab with a colour mixed throo it or shd i use standard cement

Geofix.. Geo-Fix | Home

[Dave]

Did i mention i did a spate of flagging and blocking in the early 90's..

[kilty55]

dave this stuff by the looks of it has just saved me a lotta time

[doug boardley]

3:1 seems a bit strong for my thinking, I normally do it about 4:1 with some lime in the mix to act as a plasticiser cum flex agent

[Dave]

Geofix is just one make.. jewsons and builder centre sell others.