Page 1 of 3
Posted: Wed Mar 31, 2010 10:29 pm
by Sparky77
Hi guys.
I am looking to build a patio in my garden which will be 7.1sq m using 450x450x38 smooth utility slabs to match the path round the house and safer for my daughter to play on. I will be edging the patio using block paving 200x100x50.
I need some advice on the following:
1) Subase MOT1 how deep & how many tons needed? i was looking at 75mm depth
2) I am looking to use the screeding method for laying the slabs. Is 50mm base ok using sharp sand? How many tons needed?
3) Block paving to edge against current path. Do i cement straight onto the subase?
4) is a 1:60 slope enough for the patio?
5) how deep should i dig the earth to accomodate sub base, sharp sand for bedding and thickness of slab so this will be 7mm above current level before levelling down to block paving level.
6) Screeding depth between sand and level of block paving 31mm to take into account point 5 above??
Any help would be greatly appreciated!!.......am looking forward to getting my hands dirty, beats a day in the office!!!
Cheers
Sparky77!! 
Posted: Wed Mar 31, 2010 10:42 pm
by irishpaving
Hi Sparky
@ 75mm you would be ok with 1 tonne but needs to be on good ground and well wackered
@ 50mm sand is just over half a tonne which i think is a bit on the heavy side.
) Block paving to edge against current path. Do i cement straight onto the subase? not sure what u mean
1:60 is fine for patio
Digging. i would take it down 200mm. the way you are working it out is a bit fiddly imo
Screeding depth is ok
Posted: Wed Mar 31, 2010 10:46 pm
by ilovesettsonmondays
you really dont want to screed for 38mm slabs .you should lay them on a wettish full mortar bed .
Posted: Wed Mar 31, 2010 10:47 pm
by ilovesettsonmondays
wettish .think i should have used abc check :p
Posted: Wed Mar 31, 2010 11:10 pm
by mickg
wettish
is that a mixture of Welsh and Scottish
Posted: Thu Apr 01, 2010 5:50 am
by seanandruby
have you read any of the main index? Everything you've asked is explained in great detail and thwre are pop up calculators to work out materials.
Posted: Thu Apr 01, 2010 11:39 am
by Sparky77
thanks for all the info guys.
I have looked at the main website and needed confirmation really that using a screed bed is going to be ok. On the website its says that a screed bed should be ok for the slabs that i am planning on using.
Would there be any reason not to use the screeding method??
cheers
Posted: Thu Apr 01, 2010 11:48 am
by irishpaving
Screed bed is fine. You can mix some cement into the sand about 10:1 making sure its semi dry.....
Posted: Thu Apr 01, 2010 1:30 pm
by Sparky77
could i use the 10:1 bedding mix slightly wet so that each slab can be laid individually? How much water would i need to add?
Posted: Thu Apr 01, 2010 5:18 pm
by DNgroundworks
Are you planning on wacker plating the slabs down to the existing level of your path? if so 38mm slabs will probably just crack, if it were me doing the patio i would lay them individualy on a slightly moist "wettish" cementitious bed
Posted: Thu Apr 01, 2010 8:43 pm
by Sparky77
i think that is what i will probably end up doing....using a 10:1 mix as it will be easier to level off and more managable as i will doing it myself
Posted: Fri Apr 02, 2010 5:27 am
by cookiewales
Sparky77 wrote:i think that is what i will probably end up doing....using a 10:1 mix as it will be easier to level off and more managable as i will doing it myself
for what a price of bag cement is boys use 5 to 1 far better its the difference of butter and cheap margarine on your toast :;): ???
Posted: Fri Apr 02, 2010 8:12 am
by mickg
I agree with cookie, 10:1 is too weak a mix and you certainly could not chance walking on any of the flags you laid the morning after with such a weak mixture
4:1 or 5:1 is whats required with a tacky mix, when you get a handful in your hand you can just squeeze the water out but it stays in a ball,
if its too dry it will fall apart in your hand and if used as a bedding mixture it will work but will not adhere to the flag
if its too wet it will squeeze out between your fingers, if used as a bedding mixture your flags will start to float about as you lay them, simply add a little more sand or cement to firm up the mixture
the trick is to add a little bit of water at a time and the amount of water required will vary on the water content already within the grit sand
Posted: Fri Apr 02, 2010 1:07 pm
by DNgroundworks
Agreed i should of said earlier 10:1 is to weak i use a 5:1 mix mysef, mixed as mick g has explained
Posted: Fri Apr 02, 2010 2:43 pm
by irishpaving
Sorry Sparky the mix i stated is totally wrong. It should of said a mix of 10:2 :O