[maloneranger]

We have a yard about 20ft x 20 ft, laid with 2-ft square paving slabs.

Over the years, the grouting between the slabs has broken down and weeds are growing.
So, I need to remove and replace the grouting.
I want the new grouting to be level with the slabs.

I have read on some websites, that it is possible to sweep dry cement mix into the gaps, and then water with a fine-rose.
This is attractive, since it seems much easier than using wet mix.

Has anyone tried this approach?
Does it give a good-looking finish?
Will it be weed-proof and long lasting?

Thanks for any advice.

[Lardman]

Clear out the the old properly, wet the joint the day before and then brush a *VERY* dry mix in until level, the water in the atmosphere and the joint should be enough to turn the mortar, although it takes a day or 2.

The finish will be down to however you tool (or don't) the joint, it you don't mind a gritty finish leave as is, it you want something smooth you'll need to damp it a bit and just drag a trowel over. Nothing is weed proof  soil and seeds get caught in gaps and cracks but it will be better than nothing. How long it will last is down to the prep, the mix, the depth of joint, the finish and the traffic it will be subjected to.

[bravemurphy]

I really don't like the dry method as it does not last as long as putting it in wet.

As lard said make sure it is all clean and at least the depth of the slab and no weeds and mix up some sand and cement at 4 sand to 1 cement not really wet but workable.

You could cut some hard board and place it each side of the joint to stop the mix staining the slabs and chop it in.

Let it go off for a bit ( depending how hot it is if its too hot you will not get the chemical reaction between the sand and cement and it will turn to powder) and the rub a half round jointer over it for a finish or a piece of bent 10mm copper pipe.

Or you could try one of these they really are good and fast and worth the money for a proper job.

bsXiOlukATk

[Lardman]

Or you could try one of these they really are good and fast and worth the money for a proper job.

bsXiOlukATk

I have the cartridge gun style of those - it's the worst piece of rubbish I've ever bought ! Unless you get the mix exactly right you just end up with mix in the gun and water out the back. 

[bravemurphy]

Get the mix right then 

[maloneranger]

The finish will be down to however you tool (or don't) the joint, it you don't mind a gritty finish leave as is, it you want something smooth you'll need to damp it a bit and just drag a trowel over.

Thanks, Lardman,
If I fill the gaps up to the level of the top of the paving , will the filling shrink at all, as it sets?

[maloneranger]

Let it go off for a bit ( depending how hot it is if its too hot you will not get the chemical reaction between the sand and cement and it will turn to powder) and then rub a half round jointer over it for a finish or a piece of bent 10mm copper pipe.

Thanks, bravemurphy,

I want a flat finish, level with the top of the paving.

Will the above give that?

Or will it be indented or raised?

[bravemurphy]

if you want it flat just cut it flush with a trowel.

[maloneranger]

Thanks to all!

I have decided to go with wet mortar.