In general that does not sound like a good idea since often your hose line will be 1/2 " and not large enough to supply a large flow for any normal sized irrigation system.

So perhaps your hose line is extra large like 3/4 inch or 1 inch or your system is VERY small .. I don't know via computer so it's not fair to second guess your contractor.

In general tapping in to the house supply IS the way to build your system and I would be leary of a system not designed this way.

I spent many years building systems on Long Island and never tapped into hose lines.

Good Day ...

Thank you for the advice!! Much appreciated. I will ask him to tap into the house supply.

Aother reason you will not wan to do this is because it is connected to the water supply for the rest of the house. One example is if you were working on something in the house for a while that required the water to be shut off for days at a time, your grass/plants will not get water. Instead you want to tap into the pipe before the main shutoff valve to the house so if teh house water needs to be shut off, your grass/plants will still be watered.

Tapping in before the main shut off is NOT a great idea. Especially if you have public water service. You will need to call the local water provider out to shut your water off at the street upon install and any other issues you may have in the future related to maintenance on your newer shut off valve. If you have a well, then you would still need to drain the tank, not fun. If you do not know much about plumbing, then a service call from a plumber would be needed, $$$.

Tap it after the main shut off or add a secondary main shutoff if you would like and tap in between the two.

Listen to Egghead, and don't tap into the supply before the meter. You've never seen flooding before until you've gone and done something like this.

Ok, and about the original question. There are generally three reasons someone would recommend teeing off an external spigot, and a couple of reasons why it is a bad idea.

(1) The person doing the install is just too lazy to actually make the initial point of connection to the main water line (downstream of the meter). If this is the case, what other shortcuts is he going to take during the installation of your irrigation system?

(2) Contractors who aren't licensed irrigators will use this trick sometimes to avoid having to tie into your main water line which you are required to be licensed to perform.

(3) The person doing the installation just doesn't know any better. Again, is this the person you want installing your system. Perhaps that is why their price was so reasonable.

REASONS NOT TO:

(1) Water Hammer! Ever heard the pipes rattle after someone has flushed a toilet and once it finally filled up and the toilet shut off, the pipes rattled? That's what is called water hammer. When something like an irrigation valve, or toilet valve quickly shuts off, the water that was moving through the pipes at a fast rate of speed suddenly hits a dead-end street. The noise you hear is the sound generated by the water slamming into the now closed valve and causing the pipes to vibrate from the sudden impact. Not good at 4:00am when your dead alseep.

(2) Piping in irrigation systems are sized in accordence with pressure loss and flow.

Every foot of piping generates a certain amount of pressure loss per linear foot. Too much pressure loss and the sprinkler head that requires, let's say 30 psi at the nozzle in order to operate properly, will have insufficient water pressure and may not be able to spray the intended distance.

Also, a general rule of plumbing and irrigation is to stay below 5 fps in flow velocity. We have some friction loss charts on our website which can give you a starting point at determining pipe friction loss, and when it's neccessary to increase in pipe size. CLICK HERE to check them out.

Sorry to not be of more help, but a person could write a book trying to explain irrigatin hydrolics.

Curtis

Here is a link that might be useful: EvergreenSprinklers.com

find someone else imo