I want to spray my roof with agents to kill moss. I have the recommended agent.

I don't want to climb all over the roof. A ladder at the gutter line would be okay but not convenient since I need to keep moving the ladder and the ground is not level.

I'm looking for a low pressure spray device (not sure how much pressure; sounds like the softwash guys use about 100psi). I need to reach about 20' of elevation (if I'm on the ground, perhaps 10' if I'm on a ladder) and about 20-30' laterally.

The high pressure washer for rent at HD doesn't seem like the right fit - pressure is too high and the flow rate may not be ideal for spraying the agent - may take a long time.

But I'm not sure. Will this work for what I'm trying to do? Or is there something else I should be looking at? Thanks!

https://www.homedepot.com/p/re...-1400-HDEC/315185420

I agree that the linked washer is not appropriate. Any pressure washer is going to atomize a lot of what it sprays into a cloud that will never reach the roof. Depending on your residential water pressure, a hose end mixer like those used to apply pesticide to trees may work.


https://www.homedepot.com/p/Ch...SKzgE272DVnszyRDSpJY

That looks like a better solution. But my house pressure is only 50psi (high; it gets lower during the day). I'm not sure that's high enough to fully cover the roof. I could try it I guess. I need to check on the dilution ratio of the agent.

Is there something I can use to increase the pressure to about 100psi between the house and the spay tool?

Would this work?


https://www.homedepot.com/p/RY...r-RY31EP26/306199299

quote:

Originally posted by petr:
Would this work?


https://www.homedepot.com/p/RY...r-RY31EP26/306199299

Thanks. I would use that w/ the electric pressure washer. But it sounds like the electric pressure washer I was looking at is probably not the right tool here.

The Chapin looks like it won't work either - dilution rate is challenging and it would take many refills to cover the roof (sounds like 6 gallons worth of spray).

You may find yourself at the point of "call a guy".

How about a ready to spray roof and house wash? Then refill it from their big jug.

quote:

Originally posted by konata88:
Is there something I can use to increase the pressure to about 100psi between the house and the spay tool?

A booster pump would be better than a pressure washer. The problem comes when you're not pulling the trigger and it's heating up while it's deadheading (pumping against closed sprayer). Could easily ruin the pump rinsing the roof once.

Frankly, if it city washer pressure doesn't reach the easiest thing to do is stand on a ladder.

Use a Low pressure nozzle on a power washer.

https://www.amazon.com/MINGLE-...id=1705862208&sr=8-3

Or a soap dispensing nozzle
https://www.amazon.com/K%C3%A4...ps%2C81&sr=8-13&th=1

They have about the same pressure as a garden hose. I have used the low pressure nozzles to clean a shingled roof. Sprayed chemicals with one then rinsed with the second.

As to garden hose attachments, such as this
https://www.wetandforget.com/w...forget-hose-end.html

They just don't have the range, maybe 20 ft, so unless you are up on a ladder they wont cut it for a roof.

Thanks guys - I'll look into it.

I looked into calling a guy. Prelim research suggests I should expect quotes in the $1500 ballpark. Yikes. I want to see if I can do it myself first - $200. If it doesn't work, I'll call a guy. The problem with a ladder is that my ground is not even so it makes a steady ladder a bit fun. Maybe if I got a sandbag to help level out the ladder? Is that safe to do?

quote:

Maybe if I got a sandbag to help level out the ladder? Is that safe to do?

No.

https://www.amazon.com/KARRYTO...ref_=ast_sto_dp&th=1 Maybe?

Thanks. I'll check it out but I have a Little Giant and so I don't think I can install those. But perhaps I can get another model: anybody have any experience w/ this version for unlevel ground?

https://www.costco.com/little-...duct.4000200838.html

There are sprayers that use air pressure to distribute a liquid concentrate, a canister that hold the solution, hooks up to a air compressor hose, much less aggressive than a power washer type setup, and more so than a typical agricultural applicator. I have one of these that I've never had a use for that I'd be happy to gift you if you want to try it (assuming I can find it).

Thanks for the offer!

If you could point me to the type of product you're thinking about, I could check it out and try to figure out if it may work or not.

I know exactly what you mean. Horror Freight has multiple electric pumps.

Maybe put one in your set up to boost the pressure and volume IOT hit the roof. Combine with one of those house wash mixes. They seem very “bleachy” and helped curb mildew on the shady side of my house.

https://www.harborfreight.com/...p-320-gph-63317.html

Oh nice. This might work. I didn't know about pumps like this. Thanks!

I guess I need to check that it won't be too much pressure (or flow rate) feeding into the agent dispenser. Not sure if that's adjustable. I guess I could use an in-line valve to throttle flow at least. But sounds like it would have enough pressure (40'?) to cover the roof from at least a ladder, if not from the ground.

Along the lines of the transfer pump, will this suite my needs? I'd connect the house hose valve to the input of the transfer pump, output to garden house connected to the agent dispenser container. Need the distance from the container to reach 20-30' (with 10-20' roof elevation).

https://www.homedepot.com/p/Mi...ly-2771-20/300510172

quote:

Originally posted by Speedbird:
I know exactly what you mean. Horror Freight has multiple electric pumps.

Maybe put one in your set up to boost the pressure and volume IOT hit the roof. Combine with one of those house wash mixes. They seem very “bleachy” and helped curb mildew on the shady side of my house.

https://www.harborfreight.com/...p-320-gph-63317.html

That type of pump doesn't boost much pressure (~20 psi) and lacks a no-flow shutdowns so it's what I meant when I posted earlier "The problem comes when you're not pulling the trigger and it's heating up while it's deadheading (pumping against closed sprayer). Could easily ruin the pump rinsing the roof once."

quote:

Originally posted by konata88:
Along the lines of the transfer pump, will this suite my needs? I'd connect the house hose valve to the input of the transfer pump, output to garden house connected to the agent dispenser container. Need the distance from the container to reach 20-30' (with 10-20' roof elevation).

https://www.homedepot.com/p/Mi...ly-2771-20/300510172

That pump will put up 8 gpm. Does your hose spigot deliver 8 gpm (easiest way to tell is with a 5 gallon bucket, phone's timer app, and phone's calculator).

It'll boost pressure ~32 psi (75' of head), and after 144 gallons (~18 minutes) an XC3.0 battery will be depleted.

The good news is that it has a no flow detection shutoff switch.

quote:

Originally posted by tatortodd:
That type of pump doesn't boost much pressure (~20 psi) and lacks a no-flow shutdowns so it's what I meant when I posted earlier "The problem comes when you're not pulling the trigger and it's heating up while it's deadheading (pumping against closed sprayer). Could easily ruin the pump rinsing the roof once."

Ahh, that's what you meant. I was trying to figure out what you were saying. Sorry, I wasn't familiar w/ any of this so your post kind of flew over my head.

I'm planning to buy the agent container and test it w/ the hose as-is. I'm anticipating that between the pressure to the house and then through the hose that it'll be challenging for the chemicals to reach distance 30' away, 10' up. I'm not sure I get that distance just spraying in the yard. But perhaps the container nozzle will help it go farther.

If not, transfer / booster pump may work. What if I put a Y hose connector so that there is always at least some flow. So, at the output of the pump, use a Y hose adapter with one side going to the the chem container and the other going to a second hose w/ a valve. Open the valve when I'm not using the chem dispenser and vice versa (coordinate with my wife).

quote:

Originally posted by tatortodd:
That pump will put up 8 gpm. Does your hose spigot deliver 8 gpm (easiest way to tell is with a 5 gallon bucket, phone's timer app, and phone's calculator).

It'll boost pressure ~32 psi (75' of head), and after 144 gallons (~18 minutes) an XC3.0 battery will be depleted.

The good news is that it has a no flow detection shutoff switch.

Thanks for the help. My bath (which is the most full flow faucet I have in the house) is about 3-4gpm. I have a flow meter - I'll test out the hose faucet later. The 8gpm is an up-to number? Does the pump require in-flow of 8gpm or is that just the most it could support?

I think 18 minutes would be enough time. I have an extra battery if needed. The container is only 1 gallon and I think I only need 2 gallons (unless it's recommended to do multiple passes - 1 gallon is supposed to cover 2000 sq ft?). Was planning to do 2 passes.

No flow detection - that means I don't need this Y hose workaround? If so, great!

ETA: I checked the hose faucet flow - I get a max flow of about 5gpm.