Pointing between paving slabs

[transatlantic]

There are a few areas on my patio where the gap between a paving slab and adjoining non patio conrete, where the pointing gap is less than 5mm. In these parts, the pointing has just cracked and crumbled away, I assume because it's too small of a gap to form a good bond? Or perhaps because it's too small of a gap to compress it down easily. I'm guessing the paving slabs should not have been put this close and the gap should have been bigger?

Anyway, is there a product that will fill these gaps and form a good bond? most of the pointing compounds I have seen say they're for gaps of 5mm and bigger.

It's a ripe area for ants

 

[gregmcateer]

Depending on the accessibility, you could take and angle grinder to the concrete to widen the joint - then mortar point as normal. If not, something like this might do the trick;

https://www.toolstation.com/shop/p40082 ... gIwIvD_BwE

HTH

 

[Phil Pascoe]

A lot of pointing between slabs is weak because it is often swept in dry or nearly dry and then damped down in situ - looks fine, but has no actual adhesion or strength.

 

[MikeG.]

Phil P has it right. Pointing properly takes some skill. It needs to be done with a (wet) sand/ cement mortar of just the right consistency, and without smearing it all over the face of the slabs. Builders do it dry, damp the top and smear a pointing tool over it, and move on to the next job, not in the least bothered that in 2 or 3 years the pointing will have crumbled to dust. Don't do it like that, and don't get involved in expensive pointing compounds either.

Five mm isn't ideal, but it shouldn't be a problem either, nor a cause for joint failure.

 

[sammy.se]

You could use a good quality tile adhesive or waterproof grout. Rest assured it will be strong enough.

Sent from my Nexus 5X using Tapatalk

 

[Lons]

Builders do it dry, damp the top and smear a pointing tool over it, and move on to the next job, not in the least bothered that in 2 or 3 years the pointing will have crumbled to dust.

A rather sweeping statement Mike but not all builders do that.

All my patios were laid on mortar and full buttered mortar joints as the slabs were laid which ensured a solid bed which was unlikely to fail. I never had a single callback to any of the numerous patios I laid over 20 years in business, and I wasn't the only one to use that method.

The only ones done differently were some natural stone then later grouted using a specialised resin based compound supplied by the customers and they were a pita to apply.

Bob

 

[Phil Pascoe]

Which reinforces the message to people having these jobs done - make certain the people quoting are quoting for the same job - and if you're the one quoting make certain likewise.

 

[MikeG.]

Builders do it dry, damp the top and smear a pointing tool over it, and move on to the next job, not in the least bothered that in 2 or 3 years the pointing will have crumbled to dust.

A rather sweeping statement Mike but not all builders do that.......

Fair comment, Bob. I should have said "many". I know one builder who makes a living out of repointing patios, properly.

 

[Lons]

Yes and I know a few who sweep it in as you said Mike.

One of the reasons I did it the way I described is that it's also easier, quicker and cleaner to do a proper job though it uses a lot more material than just sweeping it in. The only real downside is you have to allow time during and at the end of the job for it to go off enough to iron the joints.

 

[transatlantic]

Well, as the gap is so small, I guess I'm not going for anything structual, I just want it to look tidy. As you say, it's a skilled job, but this is only a small area, too small to get someone in. What about something like this?

https://www.amazon.co.uk/Everbuild-GEOF ... B001TN48LE

Not sure about a tile adhesive as that won't really blend in.

 

[Homers double]

Repointing a narrow gap with wet mortar is very do-able if your geared up for it, I did hard landscaping for quite a few years and the same as lons most patios were load on full wet mortar bed with full joints, I used a selection jointing irons and plasters small tools some of which I’ve ground down to get a very narrow trowel.
Ive recently used this sika product as it was in the spec for the job, I still troweled it in to the joints to compress it, time will tell how good it is.
It is very clean to use, just pour it along the joint and compress it in then top it up and smooth the top and it does set very hard.

https://www.sealantsandtoolsdirect.co.u ... 27617.html

 

[powertools]

My advice is based on personal experience.
We had patio slabs layed by a trusted builder but he pointed them with a Marshall's product I think was called whethershilde 365. The results were so bad that after 12 months I decided to spend a day and a half digging it out with a screwdriver and repointing using sand and cement.
Do not use normal building sand as it will stain the paving.