# Placing Valves on the roof?



## backyardpenguin (Aug 31, 2021)

Hello again!

I've got a quick question as I'm planning out my sprinkler valve manifold. I have have a few places in my yard that are 12" above grade where I will be doing drip irrigation. So I suspect the reasonable thing to do is ensure my valves are 18" off the ground. But I am planning on doing some 3 foot raised beds so I suspect it makes sense to just go 42" above grade with my valves. I'm also considering getting a 7 foot green house and installing misters along the top so I suspect I should just put the valves on the roof of my house to be safe.

Should I set my valve height reasonably then just get a 10$ backflow preventer on each drip line?

Appreciate any advice from anyone who has already tackled this before!

Like this one?
https://www.amazon.com/dp/B0895JF4NC/ref=sspa_dk_detail_6?psc=1&pd_rd_i=B0895JF4NC&pd_rd_w=jCasi&pf_rd_p=887084a2-5c34-4113-a4f8-b7947847c308&pd_rd_wg=DiZsN&pf_rd_r=G4PZXV0ABR1TVYR3QQ7A&pd_rd_r=3f260f9c-cc20-4922-9fa8-69b6b64c2cc9&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExR1BJSjZBVlg3SVdYJmVuY3J5cHRlZElkPUEwNTQzMTExM0IyT0U4U0ZWNVQ4QiZlbmNyeXB0ZWRBZElkPUEwOTIyNjUxMzZJUk1OUEZOUUJKRiZ3aWRnZXROYW1lPXNwX2RldGFpbCZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=


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## backyardpenguin (Aug 31, 2021)

Quote from the IrrigationTutorials.com 


> The anti-siphon valve MUST be installed above ground and MUST be at least 150mm (6″) higher than the highest drip emitter. This may prove a problem for some locations, since you would likely have to put the valves at the highest point in the yard. I have seen a anti-siphon valve installed on top of trellis in order to get it above the emitters for hanging baskets.


It looks like the prevailing wisdom is do whatever it takes to make the valve high enough.

Maybe I can build 3 foot high shed/closet outside for my valves to hide in. 3 feet of pressurized PVC with Valves atop will need to be secured somehow!

I'll worry about the Misters later...


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## bernstem (Jan 16, 2018)

If you are planning to have heads/drip/etc. significantly above ground level or above the valves, then you should consider a reduced pressure backflow. It is installed on the main line before all the valves. Unlike an anti-siphon valve or pressure vacuum breaker, you can place the irrigation heads at any height relative to it - including on the roof of the house. It makes irrigating second and third floor planters easy. Around here the backflow is typically placed right after the irrigation line leaves the house.

For more information I refer you to the online irrigation bible: https://www.irrigationtutorials.com/irrigation-backflow-preventers/


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