I received estimates on getting an irrigation system installed in my back yard. The majority of the cost is for digging down to the house's line in the front of the house (4 feet deep), splitting the water line, adding a backflow preventer, tunneling under my walk, trenching all the way along the side of the house at a depth of 2 feet, and then installing a drip system.
Today I was in my basement looking a where my water main comes into the basement, and am curious if there's a reason why they can't just split off the main where it enters inside my basement, route the main along the ceiling of my basement, and then out into the backyard through the basement wall?
Is there a reason this is not a good idea? Would love to save the time/trouble of digging all those trenches if there's no serious downside to going through my basement.
Best Answer
In most US jurisdictions, from a legal perspective, the work in the basement would fall under the local building code and its permitting, licensing, and inspection requirements...e.g. a splinkler contractor could not run the pipes inside the house and a plumber would be required, building department fees would be applicable, etc.
The pipe running through the basement that conceptually would be part of the irrigation system, is both legally and from a life safety standpoint part of the domestic potable water supply [it may be possible to get the building department to treat it as a domestic non-potable system, but that's less likely than a flat "no" from the building department]. Even if you get it approved, you'd still want a vacuum break where the pipe exits the building and there's a risk of contamination.
Anyway from a practical standpoint, one thing you're facing is the standard practices of the irrigation installer tradebase. They own Ditchwitches and shovels. They don't usually dress for walking across homeowner carpets and aren't in the habit of pulling plumbing permits. This is pushing things outside their business model...and reducing their revenue. Maybe you see a portion of whatever savings the contractor realizes, maybe the contractor just passes on the job [it depends on how much work they have, and you want the person who is busy].