• What size pipe should I use?
• Should I use thick wall (schedule 40) pipe if I want to do a good job?
• What's the pressure drop through fittings such as ells and tees?
• Should I use the flexible "poly" (polyethylene) pipe?
• Should I buy the 10 ft. straight sticks or the 20 ft. "bell end" sticks?
• How do I get the long pipe home from the store?
• Should I install automatic drains to prevent freezing?
• Can I bend the pipe if I don't have the right angle in the fitting?
• How do I get the pipe under the driveway?

We sincerely hope you will find helpful information in these pages. Be sure to check our indexed Frequently Asked Questions (FAQ) and Answers pages first to see if your questions have already been answered. If you can't find the answer you are looking for, submit your question to and we will consider including your question in our FAQs pages. Unfortunately, due to the volume of questions we receive, we can't answer them all personally, but we'll let you know if we decide to include your question and answer on our site.

What size pipe should I use?

The maximum flow for SDR 21 pipe of different diameters is given below. For runs close to or over 100 ft, refer to our detailed information on sizing pipe.

Pipe Size	Maximum Flow
1/2 inch	5 g.p.m.
3/4 inch	10 g.p.m.
1 inch	20 g.p.m.
1 1/4 inch	35 g.p.m.
1 1/2 inch	55 g.p.m.

 

Should I use thick wall (schedule 40) pipe if I want to do a good job?

In most cases, using Sch 40 pipe is a big mistake. It provides unnecessary pressure margin, costs more, increases pressure losses and water hammer effects. The only place we recommend it is on the main line before any electric valves are encountered.

 

What's the pressure drop through fittings such as ells and tees?

This information is covered in detail in our instruction section. Refer to our detailed information on fitting pressure losses.

 

Should I use the flexible "poly" (polyethylene) pipe?

This pipe is used in colder climates since it is more flexible, but in warm climates, rigid PVC pipe is preferred.

 

Should I buy the 10 ft. straight sticks or the 20 ft. "bell end" sticks?

Definitely use the 20 ft. pipe. You'll save 100 to 200 glue joints and 50 to 100 couplings on most jobs if you go with 20 ft. sticks.

 

How do I get the long pipe home from the store?

Use a roof rack or trailer, or pay to have it delivered. The advantage of using 20 ft pipe is worth the extra trouble and any extra expense!

 

Should I install automatic drains to prevent freezing?

Don't use automatic drains unless freezing is a problem in your area. In warm climates they provide no advantages and serve only to waste water by hiding small valve leaks.

 

Can I bend the pipe if I don't have the right angle in the fitting?

You can bend the pipe a little, but don't put a lot of stress on any fittings. If you need to have an odd angle in a fitting, try gluing on two ells, and rotating them together until the angle is ideal.

 

How do I get the pipe under the driveway?

There are several issues to consider before you can know the best route, or whether or not it's even a good idea to go under the driveway at all. We've known people who struggled for days to get a pipe under the driveway when it wasn't even necessary. Some people just get it in their heads that going under the driveway is a requirement, when it usually is not.

• Are you sure you want to go under the driveway? If you plan to install pipes all around your house at this time, it's probably smartest to route the main around the back yard. Of course, this is a longer route, but a larger pipe size can completely address pressure loss issues. It is almost always far simpler to spend a few extra dollars to upsize the main by one pipe size than it is to dig under the driveway. If you planned to do the back yard later, you will be making a lot of extra work to burrow under the driveway now. You should seriously consider installing the main in the back yard, tee off for future valves in the back yard and run wire to those locations now. Even if you never plan to install a sprinkler system in the back yard, it is sometimes easier to trench around the house than to go under the driveway.
• Do you have an asphalt driveway? If so, it will probably eventually collapse if you tunnel under it, so your choices boil down to digging a ditch through the driveway and repairing the damage with new asphalt, or finding another way to get the water to the other side of the driveway.
• Do you have a culvert under your drive near the street? Some homes are on lots with drainage ditches beside the road, and their driveway crosses a drainage culvert near the street. If it's possible to pass the pipe through this culvert, it may be the easiest way to get to the other side of the drive. You should in any event make sure the pipe is buried and protected from the weather and from damage during times when the ditch is filled with water.
• If your driveway is concrete, you may be able to rig up a hose and a long pipe to jet under the driveway. If possible, run a "sleeve" uder the drive, and run the pipe itself through the sleeve. The sleeve is simply a larger diameter pipe that will prevent water accumulation under the drive if the pressurized pipe should leak at some point in the future.
• If the hose and pipe doesn't work, you can rent a pipe pusher. This often requires digging a rather large hole beside the drive in which to place the pipe pusher. By the time you're done digging that hole and paying for the pipe pusher, you may feel like you would have been better off routing the pipe around the back yard.
• Some people have resorted to sawing a stip out of their concrete driveway, placing the pipe under the drive, then repairing the strip with a brick "accent" feature.

You will probably have to get one of these options to work. Don't even think about runing a pipe through your attic or something stupid like that. Just hope you are not one of the unlucky ones that finds all of these options difficult.

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