Patio DIY

chabsey

The next big project I'm going to take on is a patio, which I hope to complete using cobble-lock-type bricks. The area I'm going to put the patio on is already concrete, so I don't need hardcore. This is what I'm thinking of doing, can anyone who has done something similar before, please highlight any areas I've missed or have listed wrongly.

1. Prep the area, killing all weeds, removing all debris etc.
2. Where the current concrete base meets the grass verge, I'm thinking of laying a row of the blocks and properly concreting them into place to form a 'wall' against which the other blocks will sit flush. Otherwise the sand and blocks tumble into garden and I fail.
3. Spread a sand/concrete mix with an decline towards drainage....but not sure to what depth and not sure what type of sand....and finally unsure of ratio of sand to concrete. Any help?
4. Flatten the sand (do I need to tamp it down or simply flatten it with a board?)
5. Begin laying the blocks

So, all that said. Am I missing something obvious? Might put photos up of the proposed site, but for now thought I'd post this for initial reaction.

trotter_inc

chabsey wrote:

The next big project I'm going to take on is a patio, which I hope to complete using cobble-lock-type bricks. The area I'm going to put the patio on is already concrete, so I don't need hardcore. This is what I'm thinking of doing, can anyone who has done something similar before, please highlight any areas I've missed or have listed wrongly.

1. Prep the area, killing all weeds, removing all debris etc.
2. Where the current concrete base meets the grass verge, I'm thinking of laying a row of the blocks and properly concreting them into place to form a 'wall' against which the other blocks will sit flush. Otherwise the sand and blocks tumble into garden and I fail.
3. Spread a sand/concrete mix with an decline towards drainage....but not sure to what depth and not sure what type of sand....and finally unsure of ratio of sand to concrete. Any help?
4. Flatten the sand (do I need to tamp it down or simply flatten it with a board?)
5. Begin laying the blocks

So, all that said. Am I missing something obvious? Might put photos up of the proposed site, but for now thought I'd post this for initial reaction.

Cant advise you on the above as Im looking for similar answers myself...

Would like to see your photos as you make progress tho...

Where you getting your stones from? Have you shopped around? Where did you get the best deal?

chabsey

Have looked in a few places and there's a place in Balbriggan that is going to cost about 470 euros for 13 suare feet of cobble.

squire1

Chabsey. You mean 13Ft x 13Ft?

Sounds a bit dear to me for simple cobble-lock bricks. Around €18 per M is the going rate but it would depend on the quality.

Your process should be:

Bed your edging bricks in a 4:1 sand/cement mix. Not too wet so that it can support the bricks.

When they are gone off, spread about 2" of sharp sand (available in any builders prividers). Do not use builders sand as it will liquify when wet. Compact the sand bedding using a plate compactor if you can get one or by tamping it down to make sure it is firm and even. Screed the bedding sand so that it is about 65mm below the top of your edging bricks (assuming you are using 60mm cobble-lock)

Lay your cobble-lock onto the bedding sand.

When complete, run a plate compactor over the cobble-lock to whack them into place and prevent rocking. This will bring them down to the level of the top of the edging bricks.

Brush Kiln dried sand into the cracks between the cobble-lock and compact again, repeat as necessary until the dried sand fills the joints.

Light BBQ, open a can of beer and enjoy.

starman100

Lots of advice on this site: http://www.pavingexpert.com/

chabsey

Ok resurrecting this thread as I'm about to start this work.

I've decided to use paving slabs instead, 600mm X 600mm, sandstone slabs. I thought I was going to need to tamp the sand down but according to the guides I've read online the best way to lay them is to individually prep each section of sand, and don't tamp it, in fact you should put a few ridges into the sand before laying the slab.

Is this correct? Seems easier than trying to tamp all the sand by hand (a tamping machine would break the foundations of a wall I've just built).

Also, I think I'll upload photos of the area I'm going to work on but before I do, does anyone know how much sand I should get to cover an area roughly 13 square feet?

There's already a concrete patio in place onto which I'm going to place the slabs after putting sand down, so I've no need for a hardcore base.

Sonnenblumen

chabsey wrote:

Ok resurrecting this thread as I'm about to start this work.

I've decided to use paving slabs instead, 600mm X 600mm, sandstone slabs. I thought I was going to need to tamp the sand down but according to the guides I've read online the best way to lay them is to individually prep each section of sand, and don't tamp it, in fact you should put a few ridges into the sand before laying the slab.

Is this correct? Seems easier than trying to tamp all the sand by hand (a tamping machine would break the foundations of a wall I've just built).

Also, I think I'll upload photos of the area I'm going to work on but before I do, does anyone know how much sand I should get to cover an area roughly 13 square feet?

There's already a concrete patio in place onto which I'm going to place the slabs after putting sand down, so I've no need for a hardcore base.

You're wasting your time, materials and money proceeding as outlined above. Sandstone paving is best laid on a wet bed of sand/cement (there are other methods, but compromises finish and durability). Falls should ideally be away from buildings and not towards drains (presumably gulleys). Much easier to accomodate falls with concrete but need to be consistent and careful with fall plan for new paving. You can also use sand/cement for jointing, again my opinion a superior finish to other alternatives such as brush in sand etc. Wsah slabs ass you progress to ensure that there is no staining of stone by cement.

An alternating ' soldier ' course of 600x300mm slabs will make for a better look and finish to a small area, otherwise 4-5 sizes are particularly appealing. Some pics for ref.

chabsey

Cheers for the info, here are a few pictures of the area I'm going to be working on. As you can see the ground is uneven, old concrete.
You mention falls being away from buildings but not towards drains? I thought you were supposed to raise the sand levels in order to create a flow of run-off that would head towards the nearest drain. Is this wrong?


Also, a wet sand/cement mix, does this not mean that you're under serious pressure to lay all the slabs in one go or otherwise the sand will set?

And finally, given that the area I'm dealing with is 13sq feet give or take, and using the pictures as a guide, can anyone tell me roughly how much sand I should use? I am trying to decide whether to buy in bulk or just buy a bunch of 40KG bags.

Thanks!

Sonnenblumen

chabsey wrote:

Cheers for the info, here are a few pictures of the area I'm going to be working on. As you can see the ground is uneven, old concrete.
You mention falls being away from buildings but not towards drains? I thought you were supposed to raise the sand levels in order to create a flow of run-off that would head towards the nearest drain. Is this wrong?


Also, a wet sand/cement mix, does this not mean that you're under serious pressure to lay all the slabs in one go or otherwise the sand will set?

And finally, given that the area I'm dealing with is 13sq feet give or take, and using the pictures as a guide, can anyone tell me roughly how much sand I should use? I am trying to decide whether to buy in bulk or just buy a bunch of 40KG bags.

Thanks!

Chabsey,
your Patio needs are straightforward no need to be concerned about run-off. Over large areas a number of solutions are possible. In your case I would plan fall (1:100) away from house and otherwise lay slabs on true horizontal and parallell to house.

Mix sufficient sifficient sand and cement that you are confident you can complete, this way you will minimise any waste. Plan your route for example, if you might need to access garden from house, you will require bridging (builders board). Complete an area say 4-6 slabs, grout with sand/cement, wash area with handbrush and continue.

Your first line at hous might require a string line, as all too often external walls can be at odd angles as well as having recesses etc. Best to begin with a clean parallel line. Most importantly lay a second string line perpendicular to house which you should set as level ie fall guide. Setting out and marking can be slow but it will result in best layout, true falls and a superior finish.

Area is small so allow approx 9 -12bags (builders sand) + 2 -3 bags (max) cement.