Gutter cleanout before roof?

A few years back I did a window cleaning bid on a house and a power washing company had just finished doing the roof and old brick sidewalk. The customer was quite unhappy as the moss on the grout had been blasted off, leaving large cracks exposed. The whole front yard was a muddy, sloppy mess from roof wash overflow.

Around here we have large, old trees that fill gutters every fall and most people just let it compact and ferment, clogging the downspouts. Those that do roof washing on similar houses, do you have to clean out the gutters first to prevent a swampy nightmare?

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If real bad I tell them they’ll need to get cleaned out before I do roof.


Same… I actually like when gutters have some debris. Less sh going into your bags tied around downspouts


I figured as much. Not that I plan to do roofs any time soon, but now that my eyes are ‘open’ to PW I see dirty roofs everywhere.

On bagging downspouts. Do you just bag them before you start and leave them? Return the next day to remove them? I’m assuming you don’t remove them before you leave? I’m looking to start roofs this year and need to do some more extensive research on the topic.

I remove as soon as we are done spraying the roof. I use ALOT of surfactant and take my time. Very minimal run off…

Untie and go dump in the wood line.

I don’t rinse…I’m a let the rain do my work roof cleaner lol


Thank you sir!

I usually let the roof dry to make sure I don’t have any missed spots then remove them. Throw some gypsum pellets around any shrubs and you’re good to go


What does the gypsum do? Same thing as drywall right?

Gypsum is in drywall, but not the same stuff that they’re talking about using. Gypsum pellets are used in landscaping to help the soil absorb moisture. I’m not certain, but I believe it may also be slightly acidic, which would counteract the alkalinity of the SH to a small degree.

Currently running an experiment, and did NOT see an appreciable difference in pH of my control and the SH that I added gypsum to, at least initially. I will report back my findings directly.

Does ANYONE know how gypsum is protective against SH damage to plants and the best way to use it?

I did some reading on this a while back and I’m not sure that it’s very effective. I still use it, but I’ve added Agent Halt to the regime. Gypsum is supposed to make it easier for the salts created by SH to leach through the soil but according to experiments it can be a lengthy process. For our purposes I believe we need something instant as the grass will die quick. I still use it due to vets recommended it and it’s cheap as hell. Here is the study. Keep me updated on your results

“How gypsum works. Gypsum is used as an aid to hasten the removal of soluble salts (e.g., sodium) from soils. It is important to keep in mind that while the addition of gypsum makes it easier for soluble salts to be leached by water moving through the soil, only leaching can remove soluble salts from soil. The leaching process can be very slow, and may require several years.”


I am unfamiliar with Agent Halt. Could you elaborate and maybe source it for me please?

I follow the high end downstreaming suggestions. They do not specify it for plant use but myself and a good bit of others use it for that. I spoke to the manufacturer personally and they said it’s safe on anything but Japanese maples. I’ll usually apply it to the landscaping prior to roof cleaning. After roof cleaning I’ll give the plants a good water rinsing as usual and then apply agent halt to be left.

Why not just use Plant Wash

Easier for me to downstream agent halt. I never could find a mixing suggestion to ds plant wash. Even if I did then it’s an extra step to dissolve the crystals.

For direct application it’s 1oz per gal. Just figure your ratio to downstream