ᐅ Installing new patio slabs over existing exposed aggregate concrete slabs

Hello everyone,
we are slowly starting to work on the garden and terrace design. At the moment, we have a terrace made of old precast concrete slabs. The terrace has been there for about 40 years and definitely needs to be replaced. Since the new terrace will be a bit higher and the current slope no longer works, the idea was to lay the new slabs on a gravel bed directly over the old precast concrete slabs. Possibly, 1-2 rows of concrete slabs will be removed and filled with gravel. Is this generally possible? I assume it would be better to remove all the slabs and fill in with gravel, right? How thick can the gravel layer be to lay the slabs on? I estimate we would have about 8-10cm (3-4 inches) near the house wall. Would that be too much, or could the slabs still be set directly in gravel?
Thank you

X_SH5_X schrieb:

We are slowly getting started on the garden/patio design. At the moment, we have a patio made of old precast concrete slabs. The patio has been in place for about 40 years and will definitely be replaced. Since the new patio will be built slightly higher

This calls for a wooden deck.

It’s actually not intended to be that way.
Concrete slabs are supposed to be installed, 5.5cm (2 inches) thick. That’s why I’m asking.

If there is enough space, leave the old panels underneath and simply lay the new ones on top. Use gravel with the correct slope, as you mentioned.

nordanney schrieb:

If space allows, leave the old boards underneath and simply lay the new ones on top. On crushed stone with the correct slope, as you described.

That's exactly what I wanted to hear
Thank you

But then, if the water does not drain...