# Vetrano's Sprinkler Design and Install Journal



## Vetrano (Jun 12, 2020)

I plan to install an in ground sprinkler system this spring as part of a backyard makeover and will to use this thread to document my progress as well as obtain feedback/suggestions. We have a contractor scheduled to install a new patio in a couple weeks. Once they are done I plan to install the sprinkler system and new sod myself. Our layout will have about 900 square feet of lawn and a small flower garden (2ft x 18ft).

The system will be supplied by a 3/4" copper pipe. My static pressure is 70psi.

I found the sprinkler layout/spacing challenging due to the irregular shape and maple trees in each corner, especially on the left side of the lawn. I drafted these three layouts which can be seen below:

6 heads with radius of either 17' or 22'. My concern is the left side along the fence is only covered by one sprinkler, however the ground drops at the fence so perhaps it is ok.
Similar to layout 1 with 6 heads, but one head at the bottom left of the patio moved up 7' and its radius increased from 17' to 22'. This solves the problem with layout 1, but there is a lot of overspray against the left fence.
The third layout has 7 heads (1 additional) which allows for the radius of all heads to be closer to each other (either 17' or 18').

Obviously I would prefer options 1 or 2 with less heads, but I'm not sure if that would mean the lawn on the left side would be too dry compared to the bottom. Any feedback on which layout is better or suggestions on changes altogether?

Layout 1: 
Layout 2: 
Layout 3: 

I plan to look into specific sprinkler heads and other components once I have the layout finalized, but am open to any suggestions based on my dimensions. From my initial reading it sounds like rotating sprays (rotators) may be the best option.


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## mjh648 (Sep 1, 2020)

I have Hunter MP rotators (spray head rotary nozzle) installed and very much enjoy them.

Here's a good article if you haven't read it. https://www.irrigationtutorials.com/sprinkler-coverage-nozzle-selection-sprinkler-spacings/#:~:text=I%20still%20recommend%20that%20you,between%20any%20two%20adjacent%20sprinklers.

My biggest recommendation would be to adopt a triangular spacing method instead of the square that you have drawn. Think of the heads forming equilateral triangles.

Also the top left head you drew looks like it's going to soak about a good portion of your patio. You could look at doing something like the MP Corner strips can put down an adjustable 6 x 16 (gets bigger at bigger PSI) and maybe try to use 4 of them and have (2) sets of head to head spacing on the left tope side and then try to get triangular spacing for the bottom 50' x 17' area.

Another good tip I saw my sprinkler do was from the PVC pipe to the sprinkler head install a flexible pipe that's approx 12" so that you can place the head in any position you want and aren't stuck with where you put the T in the pvc.


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## g-man (Jun 15, 2017)

No perfect solution with the trees there.

I would grab layout 1, but add a head on the left side right where the 30' is. That should be a 180 at ~17ft too. The top left should then shrink the throw to also ~15ft, but limit the spread to around 60 degrees (like the MP corner). I think the MP2000 will work pretty good in this layout. Since the left side it more odd shape, place those heads in a separate zone that the rest. This allows you to tweak the duration if it ends up over watering.


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## SCGrassMan (Dec 17, 2017)

g-man said:


> No perfect solution with the trees there.
> 
> I would grab layout 1, but add a head on the left side right where the 30' is. That should be a 180 at ~17ft too. The top left should then shrink the throw to also ~15ft, but limit the spread to around 60 degrees (like the MP corner). I think the MP2000 will work pretty good in this layout. Since the left side it more odd shape, place those heads in a separate zone that the rest. This allows you to tweak the duration if it ends up over watering.


Second this, I was just thinking that. I'd risk putting too many heads in before too few.

And with rotators, I don't mind if they spray the tree because they're not blasting the bark off. Keep in mind too that sprinkler on the corner of the porch set to 270 degrees is gonna put out as much water as if it was 90 degrees, but over a larger area. So I might have one where that 30' mark is, and maybe another on the corner there so that 270 degree one becomes more like 180.


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## SCGrassMan (Dec 17, 2017)

Also how many GPM are you getting?


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## Vetrano (Jun 12, 2020)

Thank you everyone for your input so far. I did try a triangle spacing as suggested by @mjh648, but found it over sprayed onto my patio even more and I ended up with sprinkler heads in the middle of the lawn which I want to avoid.

Below I revised layout 1 with an additional head where @g-man suggested which provides better coverage on the left side.

@SCGrassMan, I wasn't exactly sure where you suggest adding the corner head, however we may put more flowers once our kids get a little older as indicated in the below diagram so I don't think I want a head there. Also the documentation for the Hunter MP Rotators said they provide a consistent matched precipitation regardless of the radius or arc they are adjusted for so going 90 degrees or 270 degrees shouldn't matter from a coverage perspective as long as the supply is adequate.

I still need to do a flow test out of the 3/4" copper line to figure out my GPM which will help divide the system into zones.


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## SCGrassMan (Dec 17, 2017)

The heads put out a consistent GPM rate across the entire line. Lets say thats 0.9 GPM. You're putting 0.9 gallons per minute out over 90-270 degrees. Hunter and I are saying the same thing 

Where I was suggesting an extra head is an inch south of BBQ where the cross for the 6' and 7' meet, and dialing back the one thats 270 degrees. I like 3 heads covering the same spot vs 1 or 2. Personal preference.


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## g-man (Jun 15, 2017)

SCGrassMan said:


> The heads put out a consistent GPM rate across the entire line. Lets say thats 0.9 GPM. You're putting 0.9 gallons per minute out over 90-270 degrees. Hunter and I are saying the same thing
> 
> Where I was suggesting an extra head is an inch south of BBQ where the cross for the 6' and 7' meet, and dialing back the one thats 270 degrees. I like 3 heads covering the same spot vs 1 or 2. Personal preference.


This is not accurate. The heads GPM will change with the degrees, the precipitation rate is matched (if you follow the head to head square spacing).


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## g-man (Jun 15, 2017)

Vetrano said:


> Thank you everyone for your input so far. I did try a triangle spacing as suggested by @mjh648, but found it over sprayed onto my patio even more and I ended up with sprinkler heads in the middle of the lawn which I want to avoid.
> 
> Below I revised layout 1 with an additional head where @g-man suggested which provides better coverage on the left side.
> 
> ...


This should be ok. If you want to avoid spraying the house, you can place 2 heads in the corner at 90 degrees each but with different throw. One will spray north and the other south.


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