Riven sandstone patio and path - Laying issues

[Brucieboy]

Hi There

I'm a newbie to this site (an one excellent I might add) and just about to lay 60m2 of patio and path using riven sandstone paving. There's just myself and the wife - we're both retired and in our early 60's but fit and healthy (I think and hope!!).

We've just dug up the old patio and path comprising smooth paving slabs plus a brick wall about 600mm high surrounding the patio - skipping about 10m3 in the process. The paving slabs were bedded on about 75mm of mortar below which was about 200mm of sharp sand - not MOT Type 1 or hardcore much my too my surprise. In saying this the slabs had never moved (other than a few small cracks in the jointing) since being layed some 20 years ago.

Rather than remove all the sand, I decided to leave about 100mm, break up the mortar into smallish lumps no bigger than about 40mm (using an electric breaker) and then mix this with the sand together with broken bricks and slabs. On completion, I used a wacker plate to compact to level - overall thickness typically 150-200mm. I've had to do this for a few reasons:

a. The level of the original patio adjacent the house wall was only one brick below dpc with a fall of about 1 in 75 over a length of 4.5m.

b. The footing to the brick wall (three sided) is about 600mm wide and 450mm deep and constructed of very hard concrete and quite difficult to remove.

b. The whole of the surrounding garden has been set to the original levels so to lay the new patio adjacent the house at the ideal two bricks below dpc will mean it sitting 75mm too low and obviously no good for drainage.

Finally (at last, you say!!), my questions:

1. I'm proposing to use a 50mm 5:1 sharp sand:cement moist mortar bed (with thickest 40mm flags), keep to one brick below dpc (we haven't had a problem with damp in the past)and a fall of 1 in 70. Is the fall sufficient for riven sandstone - to go any steeper will probably mean a thinner bed?

2. I'm proposing to edge with 150mm wide setts throughout (other than the house wall). Are these layed first or simultaneously with the flags?

3. If I need to cut any flags, are they layed simultaneously with the surrounding flags or after - I'm hiring a disc cutter?

4. What is recommended for jointing/pointing - ordinary sand:cement mortar or specialised material?

Apologies for rambling on, however after reading some of the blogs on this site, I'm certain there are few experts out there that can help me out.

ps I will be using a design service for a proper layout diagram.

[Carberry]

1. I would increase that fall.1:60 is standard, but I would go a bit steeper than that for the riven flags.
2. I would lay them on a bed of concrete, first or last depending on the site. Too much hassle to lay them at the same time using different mixes for the patio and the setts.
3. Do all your cuts last, it saves you money in hire and you only have to clean the mess it makes once instead of every day.
4.Premixed stuff looks nicer and is stronger but can get expensive. Either is fine it just depends on your budget.

[lutonlagerlout]

^^ exactly what he said
LLL

[Brucieboy]

Carberry and LLL - many thanks for your reply.

1. Not sure how I can overcome the fall issue for the reasons stated, i.e. I'm currently having to lay flags adjacent the house only one brick below dpc plus the level of the surrounding garden is already too low (with a footing in between). Will have to re-think.

2. Can the concrete be layed directly on the sub-base or do I have to dig this out so the concrete is full depth? Do the setts have to be haunched on the outside?.

4. Roughly how much is the cost of the premixed stuff sufficient for 60m2? Any particular product recommended?

[Carberry]

Carberry and LLL - many thanks for your reply.

1. Not sure how I can overcome the fall issue for the reasons stated, i.e. I'm currently having to lay flags adjacent the house only one brick below dpc plus the level of the surrounding garden is already too low (with a footing in between). Will have to re-think.

2. Can the concrete be layed directly on the sub-base or do I have to dig this out so the concrete is full depth? Do the setts have to be haunched on the outside?.

4. Roughly how much is the cost of the premixed stuff sufficient for 60m2? Any particular product recommended?

1. Something will have to give.You want a bigger slope with the riven paving, especially laying it as a novice, or it will puddle.
You can drop the height of the bedding a little, you can bring it up a little nearer the DPC (not best practice but can be done if necessary). You could build steps down to your garden, you could have it slope two directions.
If you post some photos might be able to offer better advice for you with regards to the gradient.

2. Sounds like you will need to dig down a couple of inches where setts are going to go so you can get 4" of concrete in there. Haunch the outside too, helps prevent any lateral movement.

3. Premixed stuff will cost you about 150-200 for that size area and that pattern. Try easipoint from londonstone.com