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Posted: Sun Aug 23, 2009 11:21 am
by big al
Thanks for your time, but my original question in another thread, except for one response, hasnt really been answered.

Its not a wind up, nor posted after a couple of drinks. Isn't it pretty pointless debating the definition of a 'government job', when your time could have been better spent answering the question? To clarify it for you the team that did it do it for a living, they did it over a week end and probably didnt tell the tax man - that's what I meant.

My question was about the slab I messed up and about a small number of others that have a one or two millimetre rock on one corner. I said I was having difficulty in getting in touch with him, which is through a third party, that doesnt mean to say I wont get in touch with him eventually, BUT I would like to know what I need to do just in case I cant.

Now if someone would be kind enough to answer - I would really appreciate it. If however your going to take the piss, I'll go to some other 'experts'.

Sorry to sound arsey about it but I posted last night in good faith and was pleased to see 6 responses this morning only to find no real answer to the actual question coupled with a hint of piss- take.

Posted: Sun Aug 23, 2009 11:36 am
by Rich H
The stone is probably Indian sandstone. None of them should rock at all. While it isn't essential that they're bonded to the bedding course (which should ideally be a sand and cement mortar and certainly not 'dry') it is desirable.

Jointing should be done with either a strong 'damp' mortar or a good quality resin-based alternative. Kiln-dried sand is not really suitable for this type of stone.

I'm sorry to say that it sounds like a bodge job and the only remedy may be to have it re-laid properly but as LLL said on the other thread, the first recourse should be to get the contractor back to fix it.




Please note that the advice given on this forum comes from self-employed people who give up their time for nothing to help people out. Making demands rarely endears posters to the regulars. 10 minutes spent reading the main site should already have told you that your patio has not been laid properly...



If you have some pictures it would be helpful in trying to suggest the best remedy.

Posted: Sun Aug 23, 2009 11:59 am
by big al
Thanks, but relaying the whole the whole patio isnt an option. Neither do I think its a bodge job. There was a guy who was doing other work for me in the garden who acted as a labourer for the team who did the job, I know him from outside doing the job and I'm confident that he would have said if he felt it was a complete bodge job.

The trouble here is I'm describing to you what I think is the material and methods that were used - and its an amauter guess.

All I want to know is how do I repair one slab that I messed up myself?

I appreciate its self employed people who come here and give their time to help people, but lets be fair - I asked a civil and polite question and was accused of being a drunk trolling newspaper hack and my question still hasnt been answered.

All I need to know - how do I repair one wobbly slab I messed up myself. Do I remove 35mm of whatever it is its laid on and fill it with cement, lay the slab, tap it in, make sure its relatively level then leave it until its set or what?

Posted: Sun Aug 23, 2009 12:37 pm
by seanandruby
Chill out m8. after a long week grafting our balls off, its nice to have a bit of a laugh. It is All part of the initiation ceromony :) Its sunday morning, time to kick back. As has been stated all the answers on on the main index, usually you look through there before asking a question. The fact the guy used KDS on the joints ( which were'nt wide enough ) tells us he is a cowboy, so please dont try tell us any different.

Posted: Sun Aug 23, 2009 12:48 pm
by Rich H
big al wrote:All I need to know - how do I repair one wobbly slab I messed up myself. Do I remove 35mm of whatever it is its laid on and fill it with cement, lay the slab, tap it in, make sure its relatively level then leave it until its set or what?
See, that's the problem.

1) No professional would lay a porous stone like sandstone on anything other than a fairly wet mix.
2) With a wet mix, the slabs need little consolidation so they won't rock AT ALL, unless they've been walked on as the mix is setting.
3) No professional would joint sandstone with KDS. The joint widths are too irregular plus the slabs are hewn with an inverse bevel - totally unsuitable for an unbound joint.

I know you're trying to get one question answered but what I'm trying to tell you is that the whole thing is a screw-up.

If you want to fix that first slab that you lifted then clean out the void completely, knock up a wettish mix of sand and cement - one bag of sharp sand to one shovel of cement should do, and re-lay the slab on it. Once it's set pour more KDS into the joints.

Although you've said re-laying it isn't an option, why not? What makes you think it has any longevity? From what you've said, re-laying it is the ONLY option. By not doing so, you will have constant problems.

Posted: Sun Aug 23, 2009 12:51 pm
by big al
Right- from what I observed they dug down - I dont know how far but the finished job is at least one brick below the damp course - I was told it should be two, but because of other factors I wont bore you with the finished job is about one and a half bricks below the damp course.

There was already a bed of dolomite there from the previous patio (which was shite I can tell you that much). Then with a cement mixer and cement and what I can only describe as dark dirty like sand (from Jewsons) that had very small stones in it, mixed it, spread it out,compacted it , in stages, a bed of this stuff that was thick like heavy sand, but it wasnt like mortar that you use when you build a wall.

Then they laid the stones down, tapped them in with a heavy rubber gavel, used a spirit level and then brushed the same substance into the joints. Most joints are 10mm -15mm wide, only a handful are closer.

Once it was finished they gave it a good soaking with a water hose pipe and told me not to walk on it for a least 24 hours whilst it set. Once that happened they brushed it with a dried silica sand and left a bag to top it up with.

When I raised the one slab myself the surface beneath was solid - the slab came up relatively easily- it wasnt stuck down.
99% of the slabs are solid, no movement at all - its just when I put this one back, I couldnt get it back right.

All I am asking is how can I fix it.

Posted: Sun Aug 23, 2009 1:02 pm
by lutonlagerlout
i concur with the above,

Al did they dig out and install a subbase?
i.e. MOT type 1
the flag you speak of which you have removed should be replaced as rich has mentioned
I cant remember how many metres your patio was but rompox easy or gftk resin mortar would be a better job than KDS
I dont know how much you paid but the fact that KDs was brushed in to the joints indicates to me that they were more concerned with getting IN and OUT quick rather than doing a proper job.
by the sounds of it its they who have taken the p!ss out of you m8
a picture would be handy,there are instructions for uploading pictures on the front page of the brew cabin

all the best
LLL

Posted: Sun Aug 23, 2009 1:23 pm
by cookiewales
big al it would seem that you have had your patio laid wrong you wont be the last you need to plan on having it laid right for a quick fix mix neat cement and water put in small jug rock slab with hand find void and pour in mix wash and leave check next day this is only a quick fix pictures would help ps we are mostly highly skilled in paving on this forum so shoddy work is a big no no you may believe its okay but from whats been posted it is far from it your friend who helped may not know what a good job is we say in wales they can talk the talk but not do the walk you would be supprised how many people fall for this good luck were here to help take a look at some of our web sites so you can see whats right and whats wrong cheers cookie :) :)

Posted: Sun Aug 23, 2009 1:56 pm
by big al
Image

This photo is the slab I messed up - please note I have brushed the surface (beneath the slab) down in my attempts to get it level again - but you can see the corners where its was solid.

Image


Image

The substance (from Jewsons) that they mixed with cement in a cement mixer and laid.

Image

Part of the Patio wet.


Image

Part of the Patio dry.


In answer to a question Im not sure what type the foundation was - all I can say is that the old patio was laid on a thin bed of sand, beneath that there was these thick blocks (4-5 inches) of cement and beneath that a bed of dolomite. They removed the concrete blocks- which were hard to get up - and used the existing dolomite. Trouble was the finish of the previous patio went right up to the damp course - you can see from the photo of the dry patio the line around the building at the bottom is a different colour and that was the reason.

Thanks for advice in advance - sorry if I have been lacking in humour - I'm just desperate for an answer.

Posted: Sun Aug 23, 2009 2:21 pm
by dig dug dan
not sure what the logic was of hosing the whole patio down, unless it was because they had badly stained the flas with cement? ???

in any case, i would be pressurewashing out the kds and applying romex as LLL says. this might help stop some of the rockers

Posted: Sun Aug 23, 2009 2:27 pm
by big al
I was told that hosing the patio down with water when they were finished would mean that the water would get through to the substance beneath and trigger it off to set/harden overnight which it did.

I helped out building a patio at a previous house with another guy I employed and he did the same thing, thats why I thought nothing of it.

Does the water not set off the concrete that's mixed in with it and harden?

Posted: Sun Aug 23, 2009 2:42 pm
by DNgroundworks
no, not aswell as if it had been mixed properly - it should have been mixed moist, ive never hosed a patio down for that reason before!

Posted: Sun Aug 23, 2009 2:46 pm
by Stuarty
The bedding should have been damp while the slabs were going down. For the mix to be correct it needs to be consistent, ie, not just damp at the corners. KDS is not suitable for a patio, only monoblocks. IMO this fella rode away on his horse. The pic of the patio dry looks to me like the left hand corner is awfy high?

Posted: Sun Aug 23, 2009 3:02 pm
by Rich H
Al, it looks like a lean mix of sharp sand and cement, made with a small amount of water. If '99%' of the slabs aren't rocking, perhaps you could re-lay those that are, then follow dan's suggestion of blasting out the KDS and replacing it with GftK or Romex. Not a difficult job and it will stand the test of time.

If you fail to do this, the KDS will wash out over time and what's left will mix with dirt, dust, algae, etc. It will be mined by ants and grow weeds. The weaker joints will compromise the slabs' adhesion to the bedding course, and the whole thing will get worse.

Posted: Sun Aug 23, 2009 3:12 pm
by big al
Rich - its the process that you do to relay the one slab that I'm after- can you advise me how.

The patio does have a slight gradient. The reason for this was that my garden originally had a gradient of about 15- 20 degrees - the side fencing posts run up at the same angle. If the patio had been laid perfectly flat it and two bricks beneath the damp course it would have severely impacted on the side fencing in that the concrete bed posts would have been completely exposed and it would have also impacted on the lawn which also had a gradient which I had raised to make flat. My whole back garden was essentially on a slope and I wanted to make it flat or as near as possible to 'flat', all things considered.

When they were mixing it they were adding water to it but not so much so it was sloppy and buttery.

Please- this is really going off topic - can someone just tell me how to rebed one slab? I'll worry about the joints another time.