Patio woes

[Vespula]

Last year after the extremely cold weather all the mortar between the slabs turned to sand.

Had it all re-pointed in the summer.

After the thaw today it has ******* well happened again!

Any ideas why?

[Nobby Diesel]

Not enough cement in the mortar mix.

[number2]

Re-pointing has been on my mind too. A task to tackle in spring maybe.

What's the deal - chip out all the loose stuff then lay in the new?

Any tips on method? Best mix?

Cheers

[herbialfa]

Pressure washer should get rid of all the loose st!

[Vespula]

Yes it will, but what is the correct mortar mix please?

[Simon_m]

Joints less than half an inch, washed sand and cement in a 1 to 1 ratio. Joints larger than half inch sharp sand in a 3 parts sand to 1 part cement ratio. Mix and brush into joints making sure they are completely filled. Brush excess off and leave to harden.

For extra protection from the elements you could use a clear sealer on the patio once dried.

[Spudler]

Simon_m said:

Joints less than half an inch, washed sand and cement in a 1 to 1 ratio. Joints larger than half inch sharp sand in a 3 parts sand to 1 part cement ratio. Mix and brush into joints making sure they are completely filled. Brush excess off and leave to harden.

For extra protection from the elements you could use a clear sealer on the patio once dried.

You have no idea


OP, get it all raked out to a decent depth(at least the thickness of the slab) and point in with building sand and cement, a ratio of 4:1 will be plenty strong enough,a VERY SMALL amount of Febmix can be used. Mix the same as bricklaying muck or slightly stiffer and point in, finish with a pointing iron/water pipe for a smooth finish.
The reason its crumbling is because its been a weak mix brushed in and watered. Tommy Walsh and GroundForce has a lot to answer for

[andy43]

The tighter it's forced into the gaps, the less likely it is to disintegrate when the frost gets it.
I'd even go so far as to say the mix is less important than the way the pointing is done.. pointing gun, not brushing, unless you're on telly

[Sir Bagalot]

Everything you need to know about Patios

[Knackered dad]

Spudler said:

Simon_m said:

Joints less than half an inch, washed sand and cement in a 1 to 1 ratio. Joints larger than half inch sharp sand in a 3 parts sand to 1 part cement ratio. Mix and brush into joints making sure they are completely filled. Brush excess off and leave to harden.

For extra protection from the elements you could use a clear sealer on the patio once dried.

You have no idea


OP, get it all raked out to a decent depth(at least the thickness of the slab) and point in with building sand and cement, a ratio of 4:1 will be plenty strong enough,a VERY SMALL amount of Febmix can be used. Mix the same as bricklaying muck or slightly stiffer and point in, finish with a pointing iron/water pipe for a smooth finish.
The reason its crumbling is because its been a weak mix brushed in and watered. Tommy Walsh and GroundForce has a lot to answer for

+1