An addition on my cottage is a slab on grade. It joins the original section of the log cabin which has the bathroom. I want the slab addition to be a laundry room so I need to run plumbing to the utility sink. I'm planning to rent a concrete saw & cut/break out a trench to lay insulated water pipes & drain connecting to the bathroom soil stack in the crawl beneath the old section. Are there any worries about cutting a slab in half like this? Are there any flaws in my plan?