My patio plan of attack

[NotAGolf]

I’ve got next week off and my task is to lay a patio. Having never done anything like this before, I thought I’d run through my plan of attack to see if someone can tell me I’m missing something/going to do something massively wrong.

First off, my shopping list:
Paving slabs (plus several single slabs to compensate for the larger area I’m doing, and any I manage to break/arrive broken)
Sand
Cement

The area will be 16sqm. I’m planning on digging to a depth of 10cm. 3.5cm of that will be the slab itself, the other 6.5cm will be the bedding mixture which consists of 10 parts sand to 1 part concrete (Based off this website that I keep seeing recommended). With these dimensions I reckon I’ll need 1.6t of sand and 157kg of cement, which equates to two bulk bags of the above sand bags and 6 bags of cement.

Stage 1 will be digging the hole. Should be nice and easy with a spade and some elbow grease. The only complication here is that the patio meets the house, so I want to ensure it slopes away from the house. To do this I’ll use a spirit level and ensure the bubble touches the markers on the side rather than sits in between them. After I’ve got it nice and level, I’ll use a whacker plate to make sure it’s nice and compact, refilling if required.

Stage 2 is to mix the sand and concrete in a mixer with a splash of water (not entirely sure how much water? Although I know when squeezed it shouldn’t run through your fingers), then lay it over the entire bed. I’ll get a couple of pegs and mark out 6.5cm and use that to ensure equal depth over the entire area. I’ll then smooth this out with a long piece of wood and use the whacker plate again to flatten everything. I’ll then re-check it’s still sloping away from the house and is still the correct depth and refill if required.

Stage 3 is to lay the patio slabs. I don’t want a big gap between them so I’m looking at ~5mm spacing which I’ll space using a couple of offcuts of wood. I’ll start in one corner and work from one side to the other. I’ll just use a rubber mallet to knock them into place, making sure they’re level as I go, and adding/removing sand underneath if necessary. I’ll probably size the patio so I don’t need to cut any slabs to size, although I can use an angle grinder if necessary. Shouldn’t be too complicated as long as the hole I dig is square, although two edges of the patio meet with the house and the shed, so if they're not square it could be awkward…

Then I’ll wait 48 hours for the cement to dry and (providing the slabs are solid and not rocking) look at filling the gaps with grouting. I haven’t decided on the method yet, but I’m pretty sure I’m going to go with something like this http://www.wickes.co.uk/invt/154002 as it looks more straightforward and tidier than a sand/cement combo.

Soooo, if you’re not bored to death after reading that, is there anything I’ve missed? Any hints? The main thing I’m worried about is the weather. Obviously if it’s chucking it down I can’t do it, but what about a light shower, or if looks like it’ll rain overnight?

Thanks.

 

[div0]

Interested in this. Just bought a new house and am planning on putting in a new patio between the house and the garden. Much of your research looks in line with what I've read myself. I'm not sure whether I'll get started this year or not - as plenty of other stuff to do as well.

Hope it goes well, will be interested in your experience and any hints/tips you pick up on the way.

 

[BennyC]

I've a patio going down in the next couple of weeks however it'll be wet mix.

I dug the hole myself, around 35 square meters with the aid of a mini digger as doing it by hand would have been back breaking!

Only advice I can offer is you might find it easier to dig with a fork to break up the earth (depending on what type of soil you have) and then scoop up with the spade. A pick axe always comes in handy too.

Will be good to see the finished results. Good luck!

 

[Dis86]

I'd recommend something like a dolomite bedding rather than sand/cement.

Put two patios down in my life, used a stone bedding for both, whacked it down and both patios are still there and perfectly level.

One's been in place 10 years (not bad considering I was only 16 when I did it), one 7.

Slabs that you've chosen look nice though however if you want it would be worth checking the colour of them more closely and possibly dye your mortar mix to match them.

 

[Adam]

Have you tried a builders merchants? They were much cheaper than wickes when I priced some stuff up. Somewhere like buildbase for example.

 

[NotAGolf]

Thanks for all the feedback.

I've a patio going down in the next couple of weeks however it'll be wet mix.

I dug the hole myself, around 35 square meters with the aid of a mini digger as doing it by hand would have been back breaking!

Only advice I can offer is you might find it easier to dig with a fork to break up the earth (depending on what type of soil you have) and then scoop up with the spade. A pick axe always comes in handy too.

Will be good to see the finished results. Good luck!

Yep the fork will be used in this mission too. Pick axe might not be wise as it's right next to a patio door so I can see chippings flying off and cracking the window! Before researching I thought a wet mix would be needed but it sounds like that may be more difficult to work (and messy) with so I think a dry/semi-dry mix will be better for my novice/clumsy ways!

ISlabs that you've chosen look nice though however if you want it would be worth checking the colour of them more closely and possibly dye your mortar mix to match them.

The grout I linked is already a buff colour so should match the tiles nicely . They also do a standard grey but obviously that wont look as good. The dolomite suggestion might be a bit overkill and expensive for my needs. I'd consider using a proper hardcore sub-level if I was parking a car on it.

Have you tried a builders merchants? They were much cheaper than wickes when I priced some stuff up. Somewhere like buildbase for example.

Not yet. I've looked online but they don't have prices So I'm going to pop into Jewsons, Covers and Buildbase as they're all local and see if they can do a better deal than the wickes option.

 

[Nightglow]

Buy your aggregate & sand loose from a builder's merchant,cheaper will come in a large dumpy bay.
But, cement may work out cheaper from Wickes, depends on your builder's merchant pricing, you will need a 3" base of hardcore (MOT type 1) well compacted, before you lay your slabs.

 

[Maccapacca]

I'd buy a Marshalls product if it were me http://www.marshalls.co.uk/transform/Products/Garden/garden-paving/ pick a product and build a shopping list then play off builders merchants against each other, Marshalls website has a stockist link.

8-10mm is more normal for a joint size

Make sure the patio doesn't cover any air bricks and is below your DPC, consider leaving 50mm against the house and filling it with shingle.

I'm not sure your laying the sand and cement mix right, are you buying sharp sand and cement not soft sand and cement, you should mix sharp sand and cement dry or with very little water and lay the slabs on this not a soft sand and cement mix which is a mortar and unsuitable http://www.pavingexpert.com/layflag3.htm

 

[Narj]

Instead of it being perfectly level, you may want to consider a slight slope for run-off of rain, depending on where it is and what your drainage is like. You don't want it pooling against the house or anything! I think when the builder I had did mine, he had a load of bits of string ddrawn taut to the slope down the garden for keeping the slaps in line and also to judge slope... bit hazy now!

 

[Hagar]

Dont lay mortar over the whole area. Place slabs on 5 dibs of mortar placed like a dice face. You can then align each paving by tapping on the corners with a rubber mallet.

This leads to a bit more mortar use when pointing the gaps but is easier to level the pavings.

Gaps for smooth paving should be 5-10mm, for imitation stone or rough edged paving, 10-20mm.

Falls are very important. Start somewhere near the middle (or the upper edge for a one way fall) and lay your falls to one in 50 to one in 100 or 6-12mm across a 600mm paving.

Use string lines and a straight plank as guides for line and falls.

 

[S@njay]

I recently laid a base for my log cabin using patio slabs.

I used a MOT subbase, then sand and cement mixture.

http://www.homebase.co.uk/webapp/wc...udeName=HBCreateTheLook/how_to_lay_patio.html

You will need a slope away from your house.

 

[BennyC]

Dont lay mortar over the whole area. Place slabs on 5 dibs of mortar placed like a dice face. You can then align each paving by tapping on the corners with a rubber mallet.

This leads to a bit more mortar use when pointing the gaps but is easier to level the pavings.

Gaps for smooth paving should be 5-10mm, for imitation stone or rough edged paving, 10-20mm.

Falls are very important. Start somewhere near the middle (or the upper edge for a one way fall) and lay your falls to one in 50 to one in 100 or 6-12mm across a 600mm paving.

Use string lines and a straight plank as guides for line and falls.

Isn't spot bedding not recommended? Obviously the voids created will affect some stones more than others.

 

[Maccapacca]

Isn't spot bedding not recommended? Obviously the voids created will affect some stones more than others.

Yes don't do this it's a bodge job, if you are using pre cast concrete slabs at 35mm and you create voids everywhere if you drop anything on them they will crack.

Sharp sand and cement lean mix is what you need, at 450 x 450 you don't even need cement really but I would.

 

[Slade2]

Instead of it being perfectly level, you may want to consider a slight slope for run-off of rain, depending on where it is and what your drainage is like. You don't want it pooling against the house or anything! I think when the builder I had did mine, he had a load of bits of string ddrawn taut to the slope down the garden for keeping the slaps in line and also to judge slope... bit hazy now!

This is quite a valid point imho, a neightbour of mine had a new shiny new patio that he then edged with the small wooden piece you can get. Since the guy who installed the patio made it perfectly level there was no run off for the water that used to run there from his garden so it would slowly fill up with water. I would just make sure any surface water has somewhere to go if you are planning on making it flat.

 

[Hagar]

Isn't spot bedding not recommended? Obviously the voids created will affect some stones more than others.

Generally you will find on a stiff subbase that when you have levelled the pavings there is little space between the mortar spots. I have laid many pavings like this and recommend it. If you then firmly tamp and infill between the slabs it fixes them securely and I have run heavy barrows across without any settlement or breakage. i have broken more when trying to level on a sand or mortar bed.

 

[j.col]

Dont lay mortar over the whole area. Place slabs on 5 dibs of mortar placed like a dice face. You can then align each paving by tapping on the corners with a rubber mallet.

NEVER do this.

I am a driveway/patio installer, have been for 20 years.
u are nearly there.
dig it out 10cm deep.
i would get a 1ton bag of MOT Type 1 hardcore, and 2 bags of sand
1 ton will cover 10m2 at 50mm deep, so for 16m2 it will be roughly 30mm deep.
best way for levels.
use a string line, get 4 or 6 bits of 25mm x 25mm bits of wood, about 20cm long. (pegs)
drive these into the ground near the edge of the dig.
so have 2 at the house, opposite corners horizontally.
2 at the other end opposite corners again, so its a square shape, or shape of patio.
tie the string line to the wood at the house end, to the level u want, then run it out vertically away from the house and tie it off on the opposite piece of wood. tie it tight.
now use a level and check the line, if needed tap down wood until u have a fall away from house.
repeat the other side of dig, also make sure they are level going horizontally as well.
rake in MOT, and whack down.
mix cement and sand, personally i would do a 6:1 mix, (b&q do a discount if u buy more than 5 bags), mix it damp but not too wet, u still want it dryish.
rake mix over dig, leave it 25mm lower than lines. and whack it.
now get some straight pieces of wood or conduit tubes around 2m long.
get a broken corner of slab, or something same thickness of slab.
tap the wood/tube down into the mix, until the slab sits on top of the tube, and top of slab is same height as line. leave the bars about 2m from each other or to suit dig.
check each end and middle.
now get another piece of wood or a straight edge, and pull this over the tubes,
u will now have a smooth finish on the sand, with no humps or hollows.
remove tubes, if they are beneath the centre of a slab, they do not need to be filled in, if they are near the edge of a slab, fill in with some of the left over mix and use a plastic float to make smooth.
get a garden hose and spray water over screeded mix using a fine rose fitting, so its like a misty spray.
now lay slabs. its easier to start in the corner against house and work out if possible. Always walk in centre of slab, NEVER near a corner
if butting up slabs tight together, just brush over kiln dried sand.
if leaving gaps for pointing, leave 10-15mm gap.
mix pointing 3:1, i prefer using plastering sand rather than building or sharp sand.

oh, and there is 4.8 of those slabs to 1m2 so u will need 80ish
oh and these work out at £12.50 per m2 and are nicer imo on offer now at 3 for 2 http://www.diy.com/nav/garden/fencing-paving-decking/paving-walling-driveway/paving/single_paving_slabs/Bradstone-Weathered-Riven-Spring-Buff-Paving-12157521
£186 for 80 slabs

 

[cainer]

we mainly lay indian sandstone for our patio's so laying on screeded sand isnt an option due to the slabs being different thicknesses, we lay all our patio's vertually as nkata describes.. by using loads of muck (soft + sharp, nearly as wet as you'd lay bricks) in 5 big tall spots it infills the gaps as you tap them down, then pack in around the edges
never been called back once for a wobbly slab in the 10 years me and a mate have worked together as a 2 man band and we have 3 year guarentee written on our advertising

 

[Soundood]

just finished mine, 24 square metres of indian sandstone

my first tip, get rid of that paving your using, get some real stone, you wont regret it,

secondly, whatever you do dont use the '5 dibs' method, the voids created can cause problems with ants/vermin etc, not to mention the damage and hassle if one is broken.

wet mix, 2-4 stones a time (1 barrow load of muck)

once done, dry mix 3 parts sand/1 part cement, brush into joints (at least 6 mm) then spray with hose, leave to dry

job done.

hers mine,

 

[NotAGolf]

Hmm, that's a few people now that have mentioned laying some hardcore/MOT down first. Is it really necessary? It's not like it's going to have much weight on it. I could understand if I was parking a car on it... Just seems like an extra cost and and extra layer of work!!

 

[troops]

Soundood, no threshold on the back door?