On 12/21/2023 at 12:31 PM, Swiss1960 said:

Taking out the tiles, creating the tunnel, putting in the pipes and reseal/retile everything is probably cheaper than finding a "specialist" that is able to drive a tunnel under your walkway in such confined spaces

The tile you show is very popular now and availabe at many stores like Homepro Go buy a box in case.

It is a easy job the current tiles can be easily removed with a hand cutter along the gout line Loosen and take what is needed out put in the connection and lay the old back in get a bag of mortar And gout.

12 hours ago, xtrnuno41 said:

IF you take soil away under the concrete path for the water pipe, you never get support back for the pavement.

In time maybe you could have a crack in your pavement. Concrete is reinforced?

I know, you said it is 15 -20 cm thick, so maybe no problem at all. But guess, you know Murphy and his law.

Keep the tunnel as small as possible, as likely also soil will disappear side ways under concrete, water jetting.

Depending on soil (sand or clay?) and how compressed it is. Or lots of stones in soil.

I know in Thailand there is soil as hard as a rock, really hard to crash, mostly used as fill up.

Then low pressure water jetting doesnt work.

Probably would do the same with a water jet. Nice video showing easy how. Try & error.(hopefully not)

I share your concerns about weakening the support for the walk way.  I think it should be just fine.  The only load will be pedestrians.  The concrete was poured in two stages both with reinforcement.  The base of 15cm and then the stamped layer of 5cm.

 

I will be trying my best to keep the tunnel diameter confined to the diameter of the 2" PVC "drill".

The Mot Tiles but “stamped concrete” looks great…. Nice looking house design also….the water Jet method should work.

Was also thinking, it was pedestrian walkway and not for a car or so.

And it was quite thick and see now ok reinforced. Well your pics show you know all about what is there, so you can make a right decision.

But just did some thinking in the way of Murphy. Another Murphy thing is, what is the quality of the concrete?   

Succes with project and all will be fine. Maybe you can let us know how it went?

Re-route.Trying to tunnel could undermine your stamped concrete path in time.

Just now, Kinok Farang said:

Re-route.Trying to tunnel could undermine your stamped concrete path in time.

Especially if your wife has gained 16 kilos like mine has.