SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

Read irrigationtutorials.com . Very good information. I don't think it's a good idea to bury piping under concrete. What if you will need to do some work on it later?
Supplying your sprinkler system from a hose bib is not recommended for a number of reasons. You will need to tap into your house main supply line.

For a really small system, you can supply it from a hose bib. Absent a diagram, it isn't clear why you want anything under the new concrete.

Are you allowed to do this since it's a townhome and you will have a committee ready to stop you? As far as a small system, I installed a small one and I save considerable time not having to water every weekend. And it was "fun" to do, sort of, and very rewarding.

I am no means an expert . . .

when you redo your patio, you are asking whether it makes sense to lay pipe while the concrete is taken out ?

I am designing a system for my front landscape which is in 2 halves and found the biggest issues are (1) water supply, and (2) trenching. Everything else is just knowing what parts to use, and actually finding the parts.

First, do you know where is the water supply. The ideal case is to tap into your main house supply. Plus, you need backflow protection.

In my case, I really feel uncomfortable doing it myself if I don't know what I'm doing, the family doesn't get water until a plumber comes to fix the problem (next day & big $), or there is an unknown leak, or I can't get the compression fitting to stop leaking, etc. My plumber charged me $369 to swap out 2 older laundry valves in my brick basement (they were tight to the wall and with bad buck in getting them off, or unable to to solder properly, no family laundry until a plumber makes a house call, so paid to avoid the potential).

This usually has nothing to do with your patio. I intend to use the hose bib because my front lawn needs are modest and the plumbing rates are outrageous.

Second, you need to know where to put the sprinkler heads for the lawn; emitters for dripping are much easier as the 1/4" drip lines are can be pulled all over. You don't want to bury pipes under concrete, but need to pull pipes under walkways. etc. Thus, the other hard part is trenching 8-10" -- you go underneath concrete IF YOU CAN'T trench along the perimeter of concrete surfaces or can't reach where you want to go.

So, good question to ask about putting down pipe when redoing your patio. But it's not like drywall where you want to pull wire while the wall is down.

The other point is your townhouse location . . . I previously lived in Silicon Valley where we had no freezing temps and can use PVC with no consideration of winterization, but now (forced) to live in No. Virginia, have to use different materials because of harsh winters -- it seems infinitely different.

If the patio is coming out it may be a good time to throw in a couple of 2-3 inch PVC conduits. I'd bury them well below the level that the concrete will be and cap them. Also, I'd probably run two separate pipes as most towns will require separate conduit for water and electric (assuming you want low voltage electric at any point in the future). PVC is pretty cheap.