Advice on pointing slate patio

[Steedo]

Good evening all

We have recently had a slate patio laid by a friend of a friend after seeing a couple of patios he had laid previously we were happy for him to undertake the work as he was previously a builder. He initially dug out the earth and then laid a sub base of ballast and cement and levelled and left to dry for a few days.

The slate slabs (600x600) have been laid by what I can only describe as dot and dab but appears to be three long lines of a motor mix resulting in cavities under slabs. After asking him not to but joint and agreeing that I would do the pointing myself I have purchased weather point 365 But have come to realise that the mix is just seeping into cavities and therefore wasting the product.

I am a little frustrated as thought the slabs would have been laid on a full bed, however having no experience of this type of job I just assumed it would be OK and only realised it was laid by this method after 3/4 of the patio laid.

Can anyone recommend how I now fill the gaps, should I fill with sand and then weather point or would people recommend another way of filling gaps?

I would like for the gaps to be neatly joined to finish off the look of the patio, but don't think I can use cement mix due to natural slate slabs??

Any friendly advice would be greatly appreciated

Thanks all

[sy76uk]

To do the job properly it really needs to come up and be re layer on a full bed.
You struggle to get slate to adhere to mortar without a bridge bond so taking them up shouldn't be a problem.
If you fon't want to do that then you could use a mortar gun to fill the voids and point up.
It would be a bodge but the best bodge I can think of.

[Steedo]

Thanks for the advice sy76uk

I thought this may be the case, I think I may cry!! I just don't understand why he didn't lay on a full bed, so confused!!!!

Now I need to decide if to bodge or pull them all back up again and lay on full bed, I may even attempt it myself, some sound advice on this forum.

Thanks though

[Steedo]

ok i have decided on the bodge job, reason being is the slabs are solid and after attempting to lift one they are well and truly glued to the cement base. i am also concerned I will run the risk of breaking slabs attempting to up lift them being slate.

So having looked at the gaps I can see that there is on the occasion a cavity from the dot and dabbing. What would be the recommendations on pointing, as originally posted the weather point just seeps under the slabs into cavities in places.

Could I therefore use a denser motar mix that may not seep under and actually remain in the gaps and allow me to finish off the patio joining or is there another method?

Thanks

[sy76uk]

One of these http://www.ebay.co.uk/itm....tJXUFYd

[Steedo]

Roger that, will collect one tommorrow from screw fix and buy some grey mortar, any recommendations on what mortar? Or will any do?

Wish me luck

[sy76uk]

You'll need a very wet3/1 mix with plastersiser.
Plastering sands your best bet.

[Tony McC]

If you've not gone ahead just yet, one 'trick' to fill voids beneath the paving such as you describe, and thereby minimise the loss/waste of jointing material, is to wash-in a fine sand (block paving jointing sand), using plenty of water to chase it into every gap, crevice and empty space beneath and between the flags.

Once the joints seem full and no further sand is disappearing, allow it to dry out for a couple of hours or so, then use a stick with a nail throught it to rake out the sand from the joints, ensuring you get as deep as you can, and certainly not less than 20mm deep. Remove this evacuated sand, keeping the now empty joints as clear as possible.

Then, you're reday for your choisen jointing material....and with minimal risk of wastefulness!