Some Notes on the Mechanical Systems

By Bob Vila | Updated Sep 16, 2020 7:18 PM

We may earn revenue from the products available on this page and participate in affiliate programs.

Mechanical Systems


Electrical, plumbing, and HVAC rough-ins should take roughly two to three weeks. The insulation will happen in a day or two. But delays are com­mon at this stage.

If you are living in the house, particularly with young children, you need to be sure that all the tradespeople secure their tools, equipment, and overall work areas daily. Establishing a child- and pet-free zone is a must, but it’s also a good idea for you to make it a habit after the workers leave each day to make an inspection—try to anticipate any hazards to you or your children, inside the zone and out. This means the work site should be clean and organized. If you have any safety problems or con­cerns, discuss them immediately with the general contractor or the subs involved.

The local building inspector will probably have visited during the foundation work, but he’s guaranteed to come now. In fact, different inspectors may arrive to look at plumbing, electrical, and other work. Unless you’re acting as your own general con­tractor, this probably won’t be your responsibility. Your subs each should arrange for the inspectors to visit—and make sure their work passes the inspections.

You should also do your own inspections, just to be confident you’re getting what you want. Among the items you might be concerned with are the following:

Check the locations of electrical plug, switch, and light boxes. Is each where the plan says it should be and where you want it? According to many codes, there should also be a wall plug for every six feet of wall space and any small sections of wall two feet or wider (such as between doors, for example) should have their own receptacles.

Has a smoke detector been hard­wired into the system? Many building codes require them today and they are a sensible and inexpensive precaution.

Are there ground-fault interrupter receptacles on kitchen, bathroom, and exterior lines?

Are the phone lines and alarm sys­tems properly located?

Are the stubs for the supply and waste lines all properly located, consistent with the plan and with your desires? Are there shutoff valves for each plumbing fixture? Have the lines been tested? If you had any special require­ments, have they been incorporated: a dedicated electrical line for your computer, an extra plumbing line for that whirlpool you want to buy when you have the spare cash, whatever.

Does each room have the specified ventilation/heating/air-condi­tioning ducts or pipes? (Heating pipes are usually an inch or more in diameter, while plumbing supply pipes are typically smaller.) Are thermostats located on intenor walls and out of direct sunlight? Does the insulation cover all the openings and chinks to the outside?

Every job is different but typically when the rough-ins are com­pleted, tradespeople expect to be paid. Many contracts specify a quarter or a third of the contract sum is payable at this stage. So get your checkbook ready.

And get yourself ready for the excitement to come. The time required for the mechanical systems may leave you feeling the process is proceeding very slowly, but from here on the finished product will begin to emerge.