Joined: Sep. 2017
||Posted: 02 Oct. 2017,12:50
|Quote (blacklimestoneproblem @ 30 Sep. 2017,07:16)|
|This link explains the different types of bedding.|
Scroll down to the "Spot Bedding" which is what Kitchen and Bathroom tilers call Dot & Dab and you will see how this can show where the mortar mix is in contact with the underneath of the stone as you can see in this photo. http://www.pavingexpert.com/images/flags/spotBedding_circles.jpg
A "Full Bed" is a mortar mix/sand which is in contact with the whole of the underneath of the slab.
There's different terminology used when laying a horizontal patio even though the principles and practices are similar with vertical kitchen and bathroom tiling.
Firstly you need to decide on whether you are going to use EasyJoint or not, because EJ has it's own special requirements which are in the instructions leaflet not on the side of the box, this includes the mix of the beds and also requires some types of stone to be sealed before laying.
The Easyjoint is a permeable coloured sand mix so water can run through the joint. It requires about 4 weeks to dry cure hard so the more rain we get the more you may want to wait for dry weather. Rain can also cause the individual sands to wash away which can also result in having to go over the joints twice, its also something Azpects the manufacturers of EasyJoint recommend, so the patio may not be completely finished for quite some time if the builder follows the instructions.
Now the considerations are, if you are having a flat level patio with no slope, water may pool in places, so the Easyjoint will help the water to escape, but this is why you need to consider the base. If the base underneath it is not permeable, water gets through the EJ and then pools underneath the slab, so as we head towards winter, this water can start freezing underneath the patio and then pop your slabs up. Its less likely to happen with big 1M x 0.5M slabs but not impossible and that still depends on how much water can pool up underneath and how cold it gets.
Ice is very effective at splitting apart things. Slabs can be like wallpaper and hide a multitude of sins.
So bottom line is, if you use EasyJoint make sure the rest of the base is permeable and going for a flat level patio will result in next to no surface pooling of water when it rains athough you can still introduce a slope if you want. You may want to find out what type of hard core is being used and this link explains the different types quite well.
The risk with this set up and it depends on your soil type, is you are more likely to experience ground movement, either soil washing away underneath the hardcore/beds or some of the beds washing away over time. The risk to slab movement increases with this type of base. Think of this like a 5 year solution.
If you go for a cement mix (chemical reaction instead of drying/curing over time) for pointing/jointing so no water can soak through to the hardcore/beds underneath, then you may want to consider a drop/slope to avoid water pooling/flooding when it rains.
At this point you can also consider things like SBR or waterproof additives in your mortar/jointing mix and any base concrete you may want to use over and above your hardcore mix. Think of this setup as a being a 10-15year solution.
SBR will make the concrete mix waterproof and very sticky which is great for small slabs right down to individual mosaics which is why its popular with kitchen, bathroom & swimming pool tilers. Now some tilers may complain about SBR as it goes sticky quickly making it harder to go back and correct mistakes which is a bigger risk when covering vertical surfaces on old uneven walls and the same will apply to some degree with patios as well, so it could also be a factor to bear in mind when having your slabs laid. A good experienced craftsman wont have any problems, an inexperienced workman will.
In my eyes a craftsman is someone who knows their trade inside and out and can do all the extra fine detailing required from time to time, so in the case of patio's, this may be cutting out appropriate shapes of stone to cover man hole covers as against building the manhole cover up so its visible in the final patio surface. Even the quality of the cut is important, some tools and discs used for cutting can give you a jagged edge others give you a smooth cut. Now whilst diamond cutters sound good, they are not always appropriate for some cuts so you may want to think about what cuts may need to be introduced around things like services leaving the building ie drain pipes and ask how these will be cut out and with what.
Theres other things you can look around for, like ask to see examples of previous work in the flesh ideally with the same stone. Some displays you may see in stone merchants will have had extra special time and attention given to it which is often not what you will get because time is money and weather can holdup/delay things and some people get booked months ahead putting them underpressure to complete on time whatever the weather especially if they are religious about working certain hours and not prepared to stay late to catch up when the weather is good for working.
As its not a highly regulated sector of commerce, the ability to start up as a "master craftsman" is very easy, anyone can copy pictures from other websites and pass them off as their own (use Google image search to see all the different websites a pic can end up on), and also check out things like if a limited company, how many times has the director gone bust. Some companies make a habit of offering a guarantee for say 10yrs and then go bust every 3-5 years, rendering any guarantee worthless. These guarantees can be a selling technique.
If the company goes into voluntary liquidation, the liquidators tend to work for who ever is paying them, so it can become a means to get lots of expensive plant & other equipment on the cheap or a means to knock suppliers which can be several or even tens of thousands of pounds of "profit".
I'd be skeptical of TV advertised trades people ranking/rating websites as I have found a way to game those with fake reviews so always try to see previous work in the flesh for piece of mind, but bear in mind this is still no guarantee your job will be any good, everyone can have a bad day, week or month so make sure they have at least some sort of insurance to keep you covered especially when digging out footings and there are foul/sewer pipes around. The ownerships of these changed to the water companies a few years back so if damaged occurred you could be liable to some major expense there as these water companies can not cut corners!
If you live in the UK, you may also want to be aware of what rules and regulations you may have to follow.
Generally there are no regs for patio's and driveways but other regs may still apply, like you cant have a step into a house thats really tall for example.
These regs change all the time, but unlike gas, electricity, water trades, theres less to follow and thus less changes.
If you have a water meter accessed where the patio is to be laid, take a meter reading before any work starts in case damage to a water pipe occurs and starts washing out the foundations over time.
I cant think of anything else, other than hope there are not any buried eletrical cables or gas cables you dont know about as this can also be costly getting them rectified quickly.
If mini diggers are coming in, make sure boards big 2m sq wooden boards get put down to spread the load as these diggers will sink into many lawns creating tracks & ruts in the lawn. Its also very easy to dig too much out which then means if a fixed price per metre or job price has been quoted, it means more hardcore is needed which eats into their profits and this could force them to take short cuts or simply spend less time, care & attention when laying slabs as they try to make some money out of it.
Always let them try to rectify mistakes first, put time limits in place and avoid day rates where possible, because some can be good at finding "problems" which need rectifying.
And above all, make sure all requirements are in writing and signed to cover yourself in the event of any problem whilst also making it clear to all parties whats required. For example you may want a flat level pation, but they might introduce a drop which you dont want and if enough work has been carried out, they may not want to rectify the work.
If its all verbal you at least need to be around to watch the work and spot any mistakes.
As to money, no problem releasing money to pay for materials, but personally thats all I'd release before its all finished. A good company should have enough cash/funds to weather the down time and not be living hand to mouth. It shows they are well run but bear in mind some are excellent manual workers but poor at admin so you have to bear that in mind as well.
Anyway just some advice from previous dealings, problems and what to watch out for. Even with all of the above, you can still get problems and bear in mind independent suppliers/stone merchants will always recommend their repeat trade customers as its good repeatable business practice & profit so even those recommendations have to be taken with a pinch of salt sometimes, especially as your business value to suppliers/stone merchants may be just a once in every 10 years. In other words, they can afford to lose you or not have your business.
Wow thank you so so much for your response, it has helped us tremendously. Really grateful thank you!
Just one more thing if you don't mind, what would you personally recommend for pointing?
Our base is permeable. Patio will have a fall on it away from house & also has aco. Something to match raj green.