Laying Paving Slabs Full Bed Mortar Tips

[Dave1UK]

Any tips/tricks for laying slabs on a mortar full bed for a complete beginner?

Had a go but it's not as easy as it looks.

Especially the aspect on how much mortar to put down for the slabs and then levelling it, not beginning with a too high rise then having to bang it down but then it doesn't come down as much as needed sometimes etc.

 

[matlob]

To get the heigh of mortar you can use a length of timber with a step that is just under the depth of you tile. Then scrape this along an existing tile and it will give you a guide on how deep you need the mix. What slabs are they?

 

[Dave1UK]

To get the heigh of mortar you can use a length of timber with a step that is just under the depth of you tile. Then scrape this along an existing tile and it will give you a guide on how deep you need the mix. What slabs are they?

That's actually a great idea!

Size wise 450x450x3.5 not sure of the type whether sandstone or whatnot.

 

[^woody^]

What sand are you using?

 

[Dave1UK]

What sand are you using?

Sharp sand not builders sand. Mix ratio of 5:1.

 

[noseall]

Any tips/tricks for laying slabs on a mortar full bed for a complete beginner?

Had a go but it's not as easy as it looks.

Especially the aspect on how much mortar to put down for the slabs and then levelling it, not beginning with a too high rise then having to bang it down but then it doesn't come down as much as needed sometimes etc.

Practise.

When you lay the muck next to an existing slab, use that slab as a reference for the new bed. Once you have got the bed right, use the tip of the trowel to remove a groove of gear, where the new slab abuts the ones laid.

You will get the hang of it as well as the water content. We constantly adjust the water content in the gear depending on thickness of bed and porosity of the slabs and the base layer.

It's very satisfying getting just the right amount of 'knockage'. Too little knockage and the slab will be hollow against the bed - too much knockage and the gear will try and bubble up through the joints.

 

[^woody^]

Lay the base mix (semi dry) to the level/fall required use a board to tamp/grade the surface so that when you lay a slab it only needs a few taps to bring water to the top to form the bond, and you don't need to mess about leveling each slab.

If the slabs have a back which is not parallel with the front - like riven or natural stone, use a thin layer of a strong builder's sand mix to bed and adjust each slab.

 

[noseall]

Lay the base mix (semi dry)

The slabs will be popping off their beds in no time.

 

[^woody^]

The slabs will be popping off their beds in no time.

when you lay a slab it only needs a few taps to bring water to the top to form the bond,

 

[noseall]

when you lay a slab it only needs a few taps to bring water to the top to form the bond

Not with semi dry screed it doesn't. Have you never screeded a floor?
Semi dry - not a prayer. You'll be relaying them the next day