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Posted: Fri May 09, 2014 10:29 pm
by Mobius
Hello everyone!
Firstly what a great website - it's been such a useful resource! Even better there's a forum as I still have few questions/dilemmas!
So, originally this started as a project to replace the rotten decking which covered the whole garden as done by the previous owners. However, after much chopping, hacking and digging I discovered the old slabs, and now have decided to replace with 6 side sawn indian buff paving.
Here's the current garden:
The area is ~20m2 (3.8-4.6 long (wavy retaining wall at the back) & 4.5wide)
So, first things first - remove the existing slabs & decking support posts and roughly level the area.
(The new slabs will extend beyond the current ones - starting at the same place on the LHS, but all the over to the RHS wall and up to the wavy wall at the back).
As it's a north facing garden, adding extra height is a good thing as the patio will get more sun (and I'd prefer not to dig it all out) so the current thought is to build a small 2 brick high (reclaimed london 65mm high) wall on top of the concrete retaining wall you can see at the bottom of the pictures. With mortar that should be <150mm high then put down 3tonnes of DTp1 and use a whacker to compact nicely to 75mm.
Where I'm facing a dilemma is whether to use 6:1 mortar individual bed or screed. As they will be fully sawn pavers, I like the idea of screeding as I think it will give me a better chance of getting everything exactly level, but I have no idea how that could work up to a wavy wall so probably individual bed is a better idea?
I plan on buying the plastic paving spacers to ensure even joint widths, and using VDW840+ to fill.
The other two snags both involve the wavy wall. This will obviously involve cutting curves in the pavers, which is somewhat daunting, but also the current foundation the wall is sat on is probably at around the same height as the finished slab height, so the pavers will butt up the foundations and not look good. Still not sure what to do about this...
Off to London Stone & Rock Unique tomorrow to look at stone!
Anyway, appreciate your thought/comments!
Posted: Fri May 09, 2014 11:05 pm
by lutonlagerlout
sounds like a plan mobius
you dont know a steve mobius do you?
I would individually bed on a wettish mix especially over the concrete
also by an idea to buy pre treated stone from londonstone
£12 a metre seems expensive until you see the cost of the sealant
~ £50 a litre
in a north facing garden it needs something or it will soon be green
cheers LLL
Posted: Sat May 10, 2014 10:39 am
by seanandruby
If that was my place i'd just replace all the damaged ones and keep the rest, less time, money and effort to achieve what is already a decent patio.
Posted: Sat May 10, 2014 10:40 am
by Tony McC
I'd actually print off some of those photies and take them with you as an aid to the discussion with your nominated suppliers, both of whom are incredibly helpful.
They can help narrow down the choices and talk you through the pre-, post- or don't-bother sealing options based on what you are trying to achieve. Get a handful of sensibly sized samples, 300x300mm (or thereabouts), even if you have to buy them, so you can see the stone in the light at your site, and in contrast with the house and its surroundings.
Posted: Sun May 11, 2014 8:55 am
by Mobius
LLL: Sorry, don't know Steve. I just use it as a name after the Mobius Strip.
So, managed to clear another 10 rubble bags of soil, remove the LHS edging wall and lift a few slabs. Seems like with some they're already laid directly on top of another. And the ones right by the house are on top of poured concrete (which sounds hollow so needs to come out) which are on top of more slabs!
Also managed to get to London Stone and Rock Unique. I think we're settled on the Harvest sawn. (edit: and buy them pre-sealed)
Some pics:
Posted: Mon May 19, 2014 2:09 pm
by Mobius
So, the area is now down to level now. Must have been 25 bags of soil come out, plus all the concrete slabs which are awaiting removal still.
I plan on breaking the bricks up and using them as base material (mainly as it costs to dispose of rubble so want to keep that to a minimum). As long as I get them small enough I assume this is ok.
I have also started building my retaining wall and did my first bricklaying over the weekend. No photos yet, but it went better than expected (took me forever mind) but the finish is ok.
So, I'm now thinking ahead...
1. Cutting the slabs: I'm planning on buying an angle grinder for the job. I will need to cut gentle curves as well as straight. I may well end up buying a curved diamond blade for this. However, would a 9" or 4" be better? (25mm Indian sandstone slabs).
2. I was going to paint an SBR mix on the back of the slabs. Is SBR in the mortar bed worth bothering with?
3. I won't be able to lay the whole area in one day. Is there any way to 'finish' an individual mortar bed, so that when I start again the next day, the bed next to it bonds properly (or am I over thinking this).
Thanks again.
Posted: Mon May 19, 2014 5:44 pm
by lutonlagerlout
1 4 inch diamond blade will work
2 SBR in the mix has worked for me for over 5 years
3 cut the mortar clean away at the end of each day leaving a vertical face, it will be fine
LLL
Posted: Wed May 28, 2014 12:53 pm
by Mobius
Thanks LLL.
4" diamond blades are now sourced (included a curved diamond blade so we'll see how that goes).
Last night I managed to clear all the old slabs and rubble after work. 1.77 tones worth, which I had to lift three times (garden to road, loading van and offload). Needless to say I'm feeling that today!
One concern I have with SBR in the mortar is the working time - as it's my first go and I have a tendency to be very (how should I put this) "deliberate" (slow) in my work, I'm concerned about the mortar going off too quickly.
Looks like a standard mixer will mix 85 litres per load. Each slab (600x600) roughly needs 0.02m3 @ 50mm deep, so one load will lay around four flags? Sounds about right?
Now, Tony mentions 10-15mins for SBR mix to go off... and I don't think I can work that quick!
As I'm going to use an SBR coat direct on the slabs, do you think I can get away without it in the mortar?
Posted: Wed May 28, 2014 5:43 pm
by lutonlagerlout
mobius IME i gauge of SBR mix will last a good hour and a half
more than enough to lay 4 slabs
LLL
Posted: Wed May 28, 2014 8:53 pm
by Mikey_C
^^ as above, you'll be fine. By third or fourth mix you'll be annoyed you can't get more in the mixer.
Posted: Thu May 29, 2014 2:12 pm
by Mobius
Ok, I'll aim to go with both, but....
Looking at Cementone SBR for example, it recommends 1ltr for 4m2 slurry coat. So 1x5ltr tub will do my 20m2 patio for the bond bridge. Fair enough.
However for mortar it says 5ltr for 25kg cement. Using the 10:1 bedding calculator for 20m2 at 50mm I need 1.5T grit sand and 152kg cement. So 1652kg/25 = 66 containers worth!
Even at half the recommended rate, that's 33 containers worth... or £578! (B&Q 17.52 5L)
Is that really how much you're putting in?!
I can only assume that 10-15mins quoted on the website is at full dosage and so if you're getting 1 - 1.5hrs working time, you're dosing at a lot less this.
Sorry for all the questions.... and thank you all for your help and patience! Progress is slow, but I've got 5 grab bags of MOT1 coming tomorrow & I'm praying the HIAB can scale my garden wall or I have very busy weekend ahead!
Posted: Thu May 29, 2014 4:50 pm
by lutonlagerlout
I put around 100ml in a mixers worth of mortar
5 litres should do your patio at that rate
LLL
Posted: Fri Jun 06, 2014 10:54 pm
by Mobius
LLL: fair enough, 100ml a load sounds good to me.
So, edge wall is now built (looks better in the flesh than the pictures, promise! Using new "reclamation's" which are really irregular didn't make for an easy introduction to bricklaying that's for sure), 6 tonnes of MOT1 in and a whacker on plate hire for tomorrow (shame it looks like it's going to lash it down all day).
Here's a couple of very blurry picture of the work so far....
Will be interesting to see how much the level drops after whacking... the MOT1 is currently flush with the bricks, but hopefully will drop ~3-4cm - enough for me to get my 5cm of mortar down with 1cm on top of the bricks for the slabs to sit on.
Posted: Fri Jun 06, 2014 11:52 pm
by lutonlagerlout
mobius type 1 is unlikely to wack down 30-40 mm
more like 20MM
sorry but I have to say it ~ what bond is that wall?
brookbond? :;):
at least the bricks are frog up
good stuff
LLL
Posted: Sat Jun 07, 2014 10:03 am
by Mobius
I'm going with the "doing it after work & bit tired bond" 
It was supposed to be english, but obviously the mistake I made was not putting the header centrally in the stretcher. The other problem I had was keeping two headers within the width of a stretcher, so near the far end of the wall it's pretty much getting towards regular english anyway :p
I appreciate you won't be able to look past that and would redo, but once the slabs are down, and I put newel posts up for the handrail I don't think (hope) the average person will notice!
So the question is, can I whack the MOT1 in the rain?