For slab-on-grade remodeling projects, mechanicals often need to be routed under the slab. A common scenario would be a new or relocated bathroom that requires new waste pipes. We have also done interior trenching for municipal sewer upgrades. This type of work can be done by hand – we’ve done it and you probably have too – but it is backbreaking work and there are more efficient ways. We would typically make the saw cuts using pneumatic saws and then the slab is either diced up with more cuts or broken with either handheld breakers or, ideally, our demolition robot. From there the concrete is removed, either in chunks/slabs or as rubble, depending on the situation. Rubble travels up conveyor belts easily, while slabs don’t. Hopefully, the site conditions are merciful and we can get a robot in to do the actual digging. If not, the digging is done by hand, using clay spades on breakers, shovels, picks, etc. Spoils can be removed (if necessary) either via buckets with or without pulley systems, conveyors, or electric mini loader, depending on the situation. If the spoils are clean sand, typically they’ll be stockpiled neatly in situ for backfilling the trench.