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Posted: Tue Jan 21, 2014 10:55 pm
by Rick
Had a large patio & paving job job all laid using Indian Sandstone.
On advice here had it pointed up with 3:1 mortar mix rather than the 'pour in dry' pointing mixes.
However it has not faired well ... after 2 yrs a lot of pointing has gone .. and needs serious attention ... company who did the job now ceased trading (were a company who frequented here)
Couple of Q's ...
# Is recommendation to still wet point with a 3:1 mix ... do any of the Lime mortar mixes fair any better ...
http://www.lime-mortars.co.uk/lime-mortar/hydraulic/NHL5
# or are any 'pour in' dry mixes yet considered good enough ?
# are pointing guns any good, I can borrow one if they are.
If anyone knows of a good company in S.Wales, looking for someone to do this ... knee surgery means I can't spend days on my knees.
Posted: Wed Jan 22, 2014 10:01 am
by Tony McC
If a 3:1 mortar has failed after just a couple of years, there was summat seriously wrong with it.
Can you be sure it genuinely was 3:1 or one of the mythical 3:1 mixes that some contractors promise when bidding for the job but which then wither to become twenty-to-plenty mixes once the job is underway and the client isn't watching?
Done properly with quality materials, there's nothing wrong with a 3:1 cement mortar, and although I do like to see lime used whenever possible, its suitability for paving is highly debatable, and if the flags or setts are laid on a cement bed, then lime mortar jointing makes no sense whatsoever.
Dry pour-in cementitious mortars are non-starters. They rely on a bone-dry and relatively smooth surface to ensure thorough joint filling without staining, and then you have little or no control over the water content, and as water:cement ratio is critical to performance, this sort of defeats the object of the exercise.
Pointing guns do have their fans. I don't count myself amongst them but that's a purely personal thing. I always found them to be more trouble than they're worth and you are still on yer poor owld knees, but then, I was always a fairly neat and competent pointer without the need for anything other than a trowel and an iron. Others swear by them, so you have to form your own opinion.
I know they are costly but for occasional paving installers and for DIYers, I think the *quality* resin mortars are the best choice for jointing. Quick, clean and reliable. If only the manufacturers could halve the cost, they'd be ideal!
Posted: Wed Jan 22, 2014 11:00 am
by Rick
Well I didn't stand there counting the shovelfulls going in mixer ... but as they were not paying for materials, and I was ordering in the cement and pointing sand ... I can confirm that quantities purchased were in about right ratios.
It was packed in and tamped down .. as watched it many times being done by the guy doing it.
Looks like I am going to have to redo it myself ... care to mention (even by PM) any 'quality' resin mortars, if they perform better I might as well use them.
I'll pressure wash out, remove any loose ... is it just a case of trowelling in about as wet as bricklaying mortar, or do you put in in as semi-dry mix ? then tamp down and tool off.
Is it worth putting in any PVA in first ?
Posted: Wed Jan 22, 2014 6:16 pm
by r896neo
If your pointing has failed that quickly i'd suspect the bedding or moving flags.
We have all seen pointing breaking up and disappearing quickly when the paving has been spot bedded so hopefully thats not the cause but it may be worth lifting one flag to check if your not convinced they were laid on a full bed because trying to re=point a spot bedded patio is pointless.
Doom merchant aside it could well just be a crap mix or drying out too quick etc etc.
Having used rompox d1 one of the resins i can't recommend it. Whilst it has held up very well structurally it has been black the whole time covered in algae because its permeable.
I now use a cement based grout like flowpoint.
Some guys on here use and like marshalls weatherpoint 365 which isn't a resin as such but is much easier to clean up than a cement based grout
Posted: Thu Jan 23, 2014 9:59 am
by Tony McC
Rompox or VDW are good brands. They will be prone to algae, as Simon mentions above, but no more so than a normal cement mortar. However, they clean up like new with a scrubbing brush or power washer, and if algaefication is an issue, treating with Wet'n'Forget once a year or even a basic weedkiller every few months will keep it in check.
Posted: Thu Jan 23, 2014 10:55 am
by Rick
Alage is an issue ... whole Patio on one side is a slippery layer or green at moment, as it sits in shade until March.
Any brands better at Algae resistance ? or I could treat whole of patio if something is suitable ... last 'clear sealers' I tried were useless
Posted: Thu Jan 23, 2014 12:10 pm
by Rick
OK .... Googled and what did I find Mr.McC videos on Youtube ....
So .. on my particular problem, should I try & point up missing parts ... or would you recommend removing & full re-jointing ?
Also which would you recommend you show:
You shows mortar - but don't know what type and using gun : http://www.youtube.com/watch?v=q0EnWcn-orc
video on 840+ http://www.youtube.com/watch?v=rZEKidBAj_A
video on 800 http://www.youtube.com/watch?v=P-GaifTrGFg
vidoe re-jointing http://www.youtube.com/watch?v=Mx3QXuZkWkU
Is one better than the other ?
(ps anybody in S.Wales who is interested in job ?)
Posted: Fri Jan 24, 2014 9:59 am
by Tony McC
I create videos usually at the request of a manufacturer or supplier because I just don't have the funds to make as many completely independent videos as I'd like. I reckon every couple of videos I make for a specific product or manufacturer enables me to make one video of my own choosing, such as the pitch jointing one I uploaded just after xmas.
The company responsible for the GftK videos are very keen on the videos I make for them; they have asked for yet more to be made in the coming year, but I've also done a video for a polymeric (Jointex - not best suited to driveways) from a different manufacturer and I've got a commission to make one for Romex next month.
There are *so* many jointing mortars around at the moment that I could fill a website with nothing but videos showing each of them, but there has to be a limit. However, I do wish one or two of the cement-based jointing mortar producers would commission a video so I could give a more balanced view of the market.
Of the two resin-based brands discussed to date, and specifically for driveway use, I would go with the 800 from Gftk or the D1 from Romex. There are minor perfomance differences between the two, but nothing that should worry us for a driveway project. So, that brings it down to price and tech support. One product is usually cheaper and one product offers superior tech support. Which matters most to you?