I hope you can give me a bit of advice, on sub-bases, I have read through the main site, where I have picked up lots, got all my depths and falls from, but I can only see that a sub-base, for a sandstone patio, is sometimes, or "occasionally" required. As a first timer I don't have the experience to know if I need one or not in my situation.
I have dug out the area for my patio, borderstone purestone riven paving, to have a finished height of 150mm below the damp course with a fall of 1:40, with a bedding layer of 50mm 10:1 sand cement.
I have spent the last four days digging by hand in the rain but am now second guessing myself on the sub-base.
It did look better, was quite neat before the rain, there are pegs in their for the levels but you can't see them any more in the mud!!!
Any advice is welcome based on the attached photo.
Also I was going to screed a dry mix, as per the main site advice, but can I mix that in a cement mixer, the main site said to add water to a mixer first which would mean I have to have a wet mortar, or should I mix wet and if so will i need more cement?
The patio will be 6m across and 3.5 deep, with sleeper steps up to the garden.
Group: Moderator
Posts: 8347
Joined: July 2004
Posted: 01 July 2007,18:54 QUOTE
The Brew Cabin uses some fairly basic coding to enable members to upload their photies. This is how to do it....
You will need:~
The photies stored somewhere on the web
The url (address) for where the photies are stored
About five minutes free time
A little bit of patience
Pleasae don't upload effing huge photies that take three days to download - you'll only annoy your potential readers. The Brew Cabin is set up to have a width of 720 pixels, so PLEASE PLEASE PLEASE keep your photies to a maximum width of 600 pixels. If you really want to impress people with ginormous photies, just provide a simple link rather than distort the carefully designed layout of the Brew Cabin.
So: you have uploaded your photies to your own webspace or a website somewhere out there in cyberspace. To make them appear, as if by magic, in the Brew Cabin, you need to include a little bit of code in your message. Here's the code...
You MUST use the square brackets around the IMG tag, and you must use a closing tag (ie: /IMG within square brackets. The square brackets are the two keys to the right of the P key on most keyboards.
You need the FULL url, so that means the http bit, the www bit, all and any backslashes or forward slashes and the full name of the photie itself. The easiest way to do this is usually to navigate to the photie using your browser, whereupon the FULL url should appear in the browser's address bar. You can copy and paste it from there - easy!
Note: due to the nefarious activities of certain one-handed surfers and eejits peddling drugs, the code does not allow photies from dynamically created sites to be uploaded. This prevents the Brew Cabin becoming some sort of animated billboard for all the crap you don't want. It also means that SOME photo-sharing sites are "out of bounds" and will not work with the above code.
If all else fails, you can always staple your photies to a ten pound note and email them to me at the address given on the website and I'll upload them on your behalf.
Courtesy of the boss off the noticeboard
You only need 3T of type one for 75mm coverage, it is a small price to pay to ensure that your patio isn't going anywhere. Put some terram down first to make sure the type 1 doesn't sink in to the clay or mud.
Your bedding layer is too thick, it should be 20-40mm.
10:1 is strong enough, though most on here would recommend 5 or 6:1. Costs you £15 for a few extra bags of cement and makes your patio solid.
Your mix should be semi dry / damp. Mix a little bit at a time in the cement mixer to ensure it is all mixed well. If you put 10 sand, then 1 cement then some water in you will end up with the stuff at the front being too wet and with too much cement in it and the stuff at the back will be dry and have no cement content.
Read here about the mix to use: http://www.pavingexpert.com/layflag3.htm
If I did 75mm type 1 then 25mm bedding I would be 100 below damp course, I suppose I have to live with that or dig another 50mm all over?
The patio is against a single story extension which has quite an overhang, and a gutter, about 35-40cm in all, do you think I could get away with 100mm below dpc, trying to get out of more bloomin diggin!
You can get away with it if patio is sloping away from house etc but it isn't best practice. 50mm isn't much, it will take you an hour or two to dig that out, it will give you a better patio and it will make you fitter.
Put the time and effort in now and you're patio will last decades instead of years.
2 things i would add
10:1 is way too weak for anything except bedding drains IMHO
we always use a half bag of cement to 12 shovels of sand for general use,this equates to about 6:1
when a lot of people try to knock up 10:1 they put in a level shovel of cement then 10 great heaped shovels of sand,thereby ending up with 15 or even 20 to 1
second point
i cant lay slabs/flags on 20mm of bedding? does anyone here?
40-60mm is ideal as if you rake it about you can still tap the flag down
you will break a lot of slabs laying them on 20mm
IMHO
LLL :;):
Ok thanks I was only going for 10:1 as I read it on here, "patio mix" but thats fine I will will do the half bag and 12 shovels.
I am glad I posted now!
So I will have 75mm type 1 and 50mm (40-60) bedding at 6:1 with a 1:40 fall starting with a finished paving level 150mm below dpc, so I my formation layer will be about 300 deeper than dpc.
I started digging out the extra 75mm for the sub-base and its all clay, to get to this level was mostly top soil which I am using to level the rest of the garden, will turf over it later, should I keep digging through it? Or live with the paving being 75mm below DPC?
Ok, I have decided not to be lazy and find excuses so I am digging deeper, but now need a skip as whats coming out is only good for building bricks with, does anyone know of a skip company in herts that drops of on Sunday?
Thanks, I could only get the skip on Tuesday in the end, so hopefully get the digging finished tomorrow.
The groundsure must be the stuff, it says non woven.
Found it on the terram website, along with instructions on how to lay a patio; its seems you lot are doing it all wrong
Prepare a loose, medium strength 4:1 cement/sand mix
Starting in one corner, place the first paving slab onto the
course sharp sand and note the area it covers.
Remove the paving slab. Place dab of cement to
correspond with each corner of the paving slab and one in
the middle.
Replace the paving slab over the dabs of cement and level
by tapping lightly with a rubber mallet.
