Up to this point, we had been rained out only two days. But one of those rains left the ground so muddy that our plumbers couldn't dig the sewer/water trench.
That set everything back because the basement floor was scheduled to be poured after the utilities were brought in. Then, the furnace/boiler was supposed to be installed. We had trouble making up those lost days, but the mechanical rough-ins went pretty well after that.
At rough-in, the heating guys do the ducts first. Then the plumbers and electricians go through and work around the sheet metal.
Our plumbing and heating subs first did the radiant heat system rough-in for the garage and basement floors. That required putting down plastic tubing before the concrete slabs were poured.
Later in the week, more tubes were run under the house's first floor to heat that area. About the same time we finally got the basement floor done. The floor was poured by backing up the cement truck to a window, extending the chute down to the basement, and filling wheelbarrows.
After the floor cured a few days, we got the radiant heat boiler installed. The second floor was carpeted, which inhibits radiant floor heat. Instead, we went with a high velocity blower that operates somewhat like forced air heating. Forced air systems are good choices, but do require some contractor attention.
Talk with the heating sub when they start running ductwork. They'll be looking for the shortest, easiest runs. That doesn't always leave registers or returns in the best spots and you might lose floor space.
Completing duct runs usually calls for cutting into some framing, so make sure the runs go where they won't cause a problem. Remember, it's something to discuss before the heating rough-in gets too far along.
The electrical subs run cable and tie in leads at the service panel and should also hook up the service leads.
The electrical sub may also do wiring for the telephones, speakers, security system, thermostat, door bells and even cable TV rough-ins. Account for these items when the framing is exposed instead of later when the walls are drywalled.
Once the plumbing and electrical rough-ins begin, it's a little harder to change things. For example, if you move a sink or the dishwasher, the plumbers have to re-route the drain and water lines.
That type of change would also make the electrician re-wire a new outlet. It's possible, but means another trip for the subs and adds to your costs. Again, avoid changes by having the whole kitchen planned thoroughly.
ERVs & Insulation
One feature that's becoming a commonplace item is an energy recovery ventilator (ERV) that keeps fresh air coming into the house. Our heating sub installed the ERV and also sealed and insulated the heating ducts to keep leakage to a minimum.
The ERV is just one item that relates to the "healthy house" concept of building. Two other important items in new construction are insulation and a continuous vapor barrier. They're usually required by building codes and are key items in providing energy efficiency and comfort.
Any soffits or interior walls running up against exterior walls should have insulation behind them and a vapor barrier overlapped to tie in with the rest of the vapor barrier. The carpenters may have to take care of these items when framing.
We included techniques like a continuous vapor barrier with overlapped and taped seams and barrier boxes around junction, outlet, and switch boxes.
Insulating the attic can be done anytime after roofing. We eventually had a fiber glass wool product blown in loose. Our sub went through the access in the second floor ceiling and sprayed the material out from there to build up the required R-value.
NOTE: Remember to have the mechanicals inspected before putting on a vapor barrier and wallboard. Insulation can be pushed aside to see the work, but you may end up tearing down the wall you just put up for a proper inspection.
Although it's not a primary "mechanical" rough-in, we included a gas fireplace. A vent duct and gas pipe were run to the firebox, the surround was mortared, and the hearth installed.
The surround did take a little more work because it has a stone facing and we decided to have a stout granite hearth.
The facing and hearth were done by two different subs. The surround first, then the hearth. But we forgot to have the stone mason mortar out a space for the long piece of granite hearth.
So, the surround ended up being too big and we had a problem to solve. Instead of changing the plan, we had the subcontractor chisel out the front section of the surround so the hearth would fit.
That was another hard (and expensive) lesson reminding us to communicate better when two subs are working the same area.