if you can work out about where a leak is, the new pipe doesn't have to follow the same route. So you might be able to avoid digging up the floor by drilling at an angle to come out through the external wall to emerge below ground level. You'd need a big SDS+ drill and either a very long drill or an extension.
You can hire these things, but Screwfix sell a heavyweight 6kg budget drill for (I think) about £60. If you have just one heavy job to do, and it goes wrong in guarantee, they will exchange it, so you will get your money's worth. Sometimes they have an offer to include a kit of budget steels for about the same price. It is too heavy for most DIY jobs. You can also use it with a chisel steel to break up concrete.
If you can afford more, there are better ones.
You can hire these things, but Screwfix sell a heavyweight 6kg budget drill for (I think) about £60. If you have just one heavy job to do, and it goes wrong in guarantee, they will exchange it, so you will get your money's worth. Sometimes they have an offer to include a kit of budget steels for about the same price. It is too heavy for most DIY jobs. You can also use it with a chisel steel to break up concrete.
If you can afford more, there are better ones.