Slab pointing

[Twistedsanity]

I have a rather large area of freshly laid slabs that will need pointing and a friend was telling me about a product that you simply brushed into the gaps and left to set, no need to mix and apparently no mess and saves a lot of labour but he couldn't remember the name of it, any ideas or experience with such a product would be appreciated!

[Rupert]

Geofix,

https://www.google.co.uk/webhp?sourceid=chrome-instant&rlz=1C1AVNE_enGB704GB704&ion=1&espv=2&ie=UTF-8#q=geo%20fix%20jointing%20compound

Edited October 10, 2016 by Rupert

[Twistedsanity]

Thank you

[R1nut]

It's pretty good stuff, I use the sika brand on my block paving and it lasts well.

[Fuddster]

Geofix lasted about three years on my patio.i used a dry mix of one to four cement to sand for repointing.labourios but would never use a brush over method again.

 

F.

[figgy]

better off with a pointing gun and a proper cement mix,will last much longer just add some waterproofing to the mix to stop frost from getiing into it

[Fuddster]

do you have to add a plasticiser to the mix in a gun?-i used one but the water just squeezed out leaving an un-pipable mix in the gun.

 

f.

[anthonychez]

You need to mix with a plasterers whisk and add feb.... placticiser. I mix 3 parts sand and 1 cement for added strength. Waterproofer is also a good idea. You must mix the motor smooth and wet enough so that it runs through the gun with ease. The complete opposite of when appling with a trowel. Make sure you have no lumps or little stones in it.

[figgy]

As above get it like wall plaster to a cream like consistency so it squeezes under the slab a little and fills the joint when applied.

[buze]

I did about 140m2 of the brush on thing a few months ago. I know it's not going to last many many years tho. It's easy to put in, but it's already darkened quite a bit and I suspect that I'll be lucky with a couple of years on it.

 

The cement seringue I used for the steps and that was a LOT of work. Perhaps it will last a lot longer but quite frankly I picked tendinitis on both arms because of that stuff, it was a HUGE amount of work to do the pointing. There's many problem -- getting the right consistency of mix is one, but the mix also drys in the gun so you really have very little time to use it. Use plasticiser, and also use *sugar* to slow the mix down. I eventually got the technics dialed in (sponging the joins, washing etc) but it was a LOT of work.

 

[Bansk65]

I did about 140m2 of the brush on thing a few months ago. I know it's not going to last many many years tho. It's easy to put in, but it's already darkened quite a bit and I suspect that I'll be lucky with a couple of years on it.

 

The cement seringue I used for the steps and that was a LOT of work. Perhaps it will last a lot longer but quite frankly I picked tendinitis on both arms because of that stuff, it was a HUGE amount of work to do the pointing. There's many problem -- getting the right consistency of mix is one, but the mix also drys in the gun so you really have very little time to use it. Use plasticiser, and also use *sugar* to slow the mix down. I eventually got the technics dialed in (sponging the joins, washing etc) but it was a LOT of work.

 

That sir, is a mighty fine job, ive 70m2 to get laid i hope its a good as finish as that.

[anthonychez]

The idea with the gun is to fill a large area with it then go over with you jointer or finger trowel. Use until your gun is emptey then it dosnt start to go off in it as said above. You want need to put sugar in... never heard of that. I use the guns alot as im a builder and they make the job much easier. Let us know how you get on

[buze]

Yeah sugar + plasticiser works really well with the gun! http://www.telegraph.co.uk/news/science/science-news/10594718/Why-sugar-helped-remove-Victoria-Line-concrete-flood.html -- the really interesting bit is that nobody REALLY knows why it works... So much for us sending man to the moon, when we can't sort out why 2 basic substances behave like that when mixed together!

 

You need very little sugar. 1/2 spoon for a 10L bucket is enough to slow it down. A bit more won't hurt but the joints won't be dry the following day (!). They *will* eventually dry tho, as normal. With 1/2 spoon that was enough to slow the mix for an hour or so, so largely the time to squirt it out, then sponge the joint and remove a bit the haze on the paving.

 

For the 'drop in sand' the *key* is to use a lot of water. Wet the paving seriously, add the sand and brush it in, making sure you wet it all the time; then once it's in the joint continue hosing water on it: the water prevents the oil base to stain the stones, and also help the sand into the joints. Seriously, even when you are done, continue rinsing as you'll see oily 'patches' rise from the sand; it'll eventually clear out.

 

And yes, good luck with the project!