Re-laying patio slabs - advice please.

andygb

I am in the middle of redoing the patio, and as the slabs are in good condition, I will be using them again. I have to do it again, because we have uprooted a couple of miniature fruit trees, which kept on growing, and the root system pushed all the slabs out of place.
So, some advice is needed please.
After getting all the slabs up, and making sure that the entire area is flat with no stones, no weeds or roots, what do I do next?
Should I be putting down a layer of sharp sand and laying the slabs straight on to that, or is there another method?
I will be using a strong mix of weedkiller first, but do I need to put down any membrane or is that OTT?

Mortgage_Reduction_Novice

Just bumping as I'm interested in the answer (neighbours large tree roots had made a right mess of path but slabs still in good condition.

pledgeX

Every time this topic comes up on here this website seems to get a mention:
http://www.pavingexpert.com/

But I too will be laying a patio soon so am interested to hear people's feedback. As a very rough guide my current understanding is something along the lines of:
- Clear the space and flatten it out to a depth of ~10cm, maybe with a whacker plate to ensure it's flat (or sloping slightly slightly away from your house).
- Put down a layer of bedding (~6cm deep) which consists of 10:1 sharp sand:cement with a splash of water so it's not too dry
- Whacker plate to ensure it's flat, then double check with something long and flat to ensure it's level, topping up and re-whacking if necessary
- Lay the slabs down

The joining method is the bit I'm not sure of at the minute. It sounds like butting them up to one another is the best option (obviously this is only possible with straight edged slabs), but I feel like that would be less secure. However the alternative sound more trickier, and aren;t as nice to look at.

Let me know how you get on and if you've got any tips as I've got a month until I do mine!

andy.m_2

I would lay a membrame under there to prevent any grass or weeds grinning through, sometimes called terram you could probably get some from any building site in the area and a drink in the Foreman's pocket!
Well compacted ground and a layer of either sand or snad/cement xix will be fine.
Brush sand into the gaps afterwards to help rocking etc.

wallbash

I am a fan of 'slablayer'.
http://www.wickes.co.uk/slablayer-20kg/invt/153707/

Its easy , get the product level ( slight fall if required) take as long as you need . Water with a watering can ( with a rose). Lay slab on top
( how easy is that!)

Cost , compares very favourably if you take in consideration there will be very little waste , and no heavy mixing .

As for pointing ........... please please dont think of brushing in a dry mixture with a broom , it NEVER lasts.
Get yourself a blanket to sit on , small pointing trowel , a radio and a nice sunny day and take your time.
Mixture should be very dry , squeeze in your hand , if it leaves a stain on your hand its too wet.
Use a 'chopping' motion to force into crack , then trowel flat, leave an hour light sweep.
You will then be able to pressure wash your patio with ease.

tony6403

Wallbash is right that brushing in a dry mix does not produce joints that will stand the test of time.
Another way of pointing which, after some testing with the wetness of the mortar, is far quicker is to get a mortar gun - pasted Screwfix advert below.
Innovative tool for repointing walls and patio slabs. Excellent joint penetration. Handy for awkward places. Aluminium body with metal handle