Jointing problems

[Nick J]

After finishing a large paving job this summer (about 200 metre squ, mixed thickness Indian Sandstone) I received an email from the client complaining about the joints. At first I thought they were trying it on to get out of paying the last stage (we had two bounced cheques and a "reduced" 2nd stage payment so I thought they were pulling a fast one). Anyway they paid up in the end and the matter died down.

Last week, though, I received another email asking when I was returning to look at the patio (I've been away looking at some places in France this summer). So I went back today to have a look.

To be fair, it turns out that they have a point (excuse the pun) and not just being overly picky. It seems that some of the joints have shrunk, and 2 or three of the joints seem to have crumbled out (After less than 6 months)

They are expecting us to replace all of the pointing (including the good stuff) I've argued that we had followed the exact guidelines for jointing, (3:1 cement mortar). We wetted down the slabs when it was hot, to control suction, we shaded the area that was pointed etc, etc.

So, I'm at a loss to explain why the joints have shrunk in places, and to why some of it has crumbled out? I will of course put it right, and I guess its out of my own pocket, but for future reference I want to know why the joints failed? I would say I will need to replace at least 40% in total, I will argue that out of my own pocket I will not replace a sound joint. I am looking to doing this work using a polymeric jointing compound.

As I am a bit old school, I've grown up in the building using mortar joints, but I'm going to embrace the new technology and go with a jointing compound. So What's the best stuff for the job? My local merchant supplies cementone wide jointing compound, but I've seen on the net a few other companies, Silka, Geofix, Romex etc.

Recommendations and explanations appreciated!

[ilovesettsonmondays]

i am an old traditionalist too and use sand and cement and wet point .one thing not to use is geofix.you could use easipoint through the gun ,which you wont have to go back too .cracking gear.

[London Stone Paving]

Hi Nick

Dont want to sound like the bad guy but, surely the replacement mortar will need to be the same as the original stuff just for looks, other wise wont it look like a bit of a mish mash?

Going to your original request the quickest way of doing it by a long stretch will be romex. If you opt for the two part solution though it will leave a shine on the paving for 3-6 months, so let client know.

Easipoint is another option. Benefit to Easipoint is the wide range of colours available. Will take much longer to installl than romex though

Steve

[London Stone Paving]

Oh Yeh

dito i love sett mondays, dont use geofix!!!

[lutonlagerlout]

was it warm when the patio was pointed?
200m is a larger patio and i guess it took some time to point
did the muck go "off " too much as it was sitting there?
i like instarmac gunpoint and easipoint
quality products with datasheets to prove their worth
cost a fair bit to do 200 m though
LLL

[Nick J]

The patio is quite large, we did it in three stages; first stage was a path around 2 sides of house, which we pointed as we laid, this was done last November and has only one joint with hairline crack. We didn't get back to the job until around April/May so the 2nd stage was a larger area on side of house and the largest area at the back, lots of stone walling steps up to Garden etc. The jointing was done at about 24 degrees average temp and we wetted slabs at start of the day to control suction, changed the mix regularly etc. 3rd stage was a patio in a walled sunken area, the jointing was done around the same time of year about same temp.

We noticed a very small amount of shrinkage at the time, and replaced a small section of about 1 metres square, When we left the job everything looked good the stuff that had gone off already was fine. The problems have occurred mainly on the last section.

I feel that it must be the heat, and to be honest I don't lay flags full time, but I have been in general building for over 20 years and this is the way we've always done patios! The cracking around the edges of some of the joints looks like shrinkage to me, I can't imagine its due to movement as we laid the stuff on about 4 inches of compacted hardcore.

Anyway, I will of course do my best to rectify the situation for the client, I trade on my name and all of my work is local (small town) so I can't leave a job looking tatty. I really don't want to re-point the whole lot though and luckily the bad looking joints are grouped together and not scattered about randomly, so I want a product that matches 3:1 cement mix as close as possible.

I looked into easipoint and disregarded it at first as I've always had problems with using a mortar gun. Romex looks good but is expensive and I've researched Geofix on here now so will not use that.

How about the cementone product? My local Bradfords will do me a price on that and Silka is cheap on the net. Any other alternatives, I haven't got the time to try mortar again.

[lutonlagerlout]

instarmac and easipoint are a doddle once you get the timings right
myself and my colleague (him knocking up and filling the tubes,me squirting and pointing ) did 65 M 2 in 7 hours in august that used 7 bags though so at £22 a bag it worked out expensive on the materials but we saved on labour
it sounds like you had a batch fail with some of the pointing
LLL

[cookiewales]

instarmac and easipoint are a doddle once you get the timings right
myself and my colleague (him knocking up and filling the tubes,me squirting and pointing ) did 65 M 2 in 7 hours in august that used 7 bags though so at £22 a bag it worked out expensive on the materials but we saved on labour
it sounds like you had a batch fail with some of the pointing
LLL

hi boys hi boys i pay 11 pound bag instarmac 20kg as lll says use it and you will not go back to normal good to work with robin is on the brew cabin :;):

[haggistini]

i pointed 40m2 indian sandstone in an hour on my own last week with cementone and a soft brush, as long as you compact or work it in well then strike it gently its works fine. i used 3 tubs @ £23+VAT. use the gray and try a small area, and if both parties are happy with the colour or look go for it if not the other option repoint the lot!

[haggistini]

P.S. make sure the area is dry and you cover it after with dpm it dont like the rain!

[lutonlagerlout]

thats some going in an hour haggi
is it struck or brushed finish?
LLL

[haggistini]

brushed and the odd strike here and there around the gullys