I've spent decades maintaining, repairing, and rehabbing houses. And when it comes to working on pre-existing structures, no two are ever alike. Building codes change continuously, a great deal of past work is performed by do-it-yourselfers (DIY), handymen and even general contractors are frequently not licensed in all trades, and all too often time-saving shortcuts are taken before infrastructure work is closed up. So if the job gets accomplished at the right price, why does any of this matter?
Because future problems are unlikely to occur within the first year or two following completion. Caulking and sealing -- too frequently a superficial wrapper on substandard work -- dries, cracks, and can result in leaks that manifest far from the point of entry. Electrical junction boxes without outlets or switches get sealed over by inexperienced drywallers. Plumbing feed and drain pipes are often forced into position -- especially in older structures -- creating torque that eventually causes a breach. Carpentry (windows, doors, flooring, stairs, built-in cabinets & shelving) may not have the necessary framing and support structure. These are just a few examples of incorrect and poorly executed work that occurs.
Case in point: I recently received a call from an old client from when I was a general contractor over a decade ago. He would have a leak in the living room below the second and third floors when the second-floor shower was in use, yet the second-floor bathroom was some distance from the living room on the second floor grid. I had installed a new kitchen when the house was being reconstructed and had not been involved with building the portion of the house in crisis. Nonetheless I was happy to advise. In lieu of a project photo album, I suggested progressively cutting out foot square sections of ceiling on the first floor. The problem turned out to be an improperly set marble shower bed and drain assembly leaking water that traversed 10 feet of uneven floor joists before falling into the living room. Remediating the first floor ceiling cost almost as much as reconstructing the shower bed and could have been precluded had there been an original rehab construction process photo album.
So whether you're an experienced property investor, accomplished DIY, or know absolutely nothing about the processes you're contracting, take pictures. Photograph the work being done everywhere and label the photos every day at minimum, and especially following demolition and infrastructure rebuilding, including framing, electrical and plumbing rough-ins. Keep the pics and files in a place were they can be accessed for years to come. You'll save a bundle should problems arise down the road.