How to install pavers over existing hardscape?

Question

Hi Workshop,

I am updating an existing outdoor area (photos attached). A large section already has some pavers installed prior to when we bought the house. They have not moved a mm since we bought the place. On the right, we have an existing unreinforced concrete path. There used to be a brick wall in the middle but I have got rid of that

We have some large 1000mm X 500mm second hand granite pavers which we want to lay so we have a consistent surface in this area.

I was intending to fill in the middle where the wall used to be with with gravel then concrete to level it off, then place the tiles over the top.

There is a level difference (couple of cm) between the existing concrete path and the pavers, which will need to be accounted for.

I was thinking to use a thick layer of sand/mortar mix below the tiles, allowing me to take up this level difference and create slope back to the garden bed. Would this work? Is sand/mortar suitable for this application? Or do a need a level surface then adhesive? Any other suggestions?

EricL · Answer

Hello @bob17

Thanks for the photo it really helps in assessing the area. I don't recommend laying the 1000 × 500 granite pavers directly over this entire area with a thick mortar bed as it currently stands.

The existing dark pavers appear to provide a reasonably substantial base, provided they are firmly bonded and don't move. However, the narrow strip of loose rubble/gravel beside them is the weak point. I would dig that loose material out rather than trying to bridge across it with mortar. Compact the ground beneath it, install and compact road base, and then bring that section up with concrete so you have a solid, continuous substrate alongside the existing paving.

Please note that any large section of soil needs to be reinforced with concrete just like the middle section. Having a poor foundation will result in the pavers moving and coming loose.

Before we go any further can you please tell us how thick the granite pavers are? This will help us in providing a recommendation for your paving project.

I also suggest having a look at these guides:

* How to Pave Over Concrete 
* How To Lay a Base For Pavers 
* How To Lay Pavers 
* How To Pave A Pathway 
* Paths & Paving | D.I.Y. Advice

Please remember to wear personal protection such as gloves and goggles.

If you have any other questions we can help with, please let us know.

Eric