Pressure Washing Solution

[Supermatch]

Any recommendations on a plant-safe solution for pressure washing concrete and brick stairs and walkway to prevent mold/mildew growth? Have some shrubs and a Japanese maple on either side that I don't want to accidentally kill. Bonus points for availability at Lowes or Home Depot.

 

[MacEntyre]

Prevent? Or Clean? Two different things...

 

[BloodRunsThicker]

Water them down before and rinse after spraying chem and then also after washing and they should be ok. Thats what we do here. The multiple rinses of plants is key. Wife has plenty of them i have to be careful about

Bleach works best for me. Pool supply SH (sodium hypochlorite)

 

[barf]

Why not pressure wash with water, then just spray unpressurized prevention treatment?

 

[AverageDad]

I own operate a pressure washing business. As posted above, nothing works better than bleach/sh. Pool or pressure washing supply stores are the go to. Also like @BloodRunsThicker posted, pre wet and rinse well afterwords. What I do when there are delicate plants is I will also use a bleach neutralizer afterwords. You still have to rinse heavily to be sure any remaining bleach is diluted enough for the root system.

Be careful with the Japanese Maples, they are the most delicate plants/trees and do not tolerate bleach well at all.

You could also hire a professional, just be sure they are insured and cover plant damage.

I usually pre wet the concrete, pressure clean concrete/brick, then post treat with about a 4-6% bleach/sh solution.

 

[Timfoilhat]

is it possible to stand in the plant bed and wash "away" from the bed? If it's on both sides set up a plastic tarp to catch the spray and shield the plants?

 

[Supermatch]

Prevent? Or Clean? Two different things...

Clean is a given, but I don’t want it to turn black two weeks later.

is it possible to stand in the plant bed and wash "away" from the bed? If it's on both sides set up a plastic tarp to catch the spray and shield the plants?

Not really. Too tight to stand in, but tarping is an option.

Sounds like pressure wash and then a bleach solution in the handheld sprayer is the way to go, followed by a bleach neutralizer. Thanks, all.

 

[Me.]

post treat with about a 4-6% bleach/sh solution.

Isn’t 6% about what common laundry bleach is? Do you spray at that rate and just leave it on?


Do you use the 10% stuff and mix it 50/50 with water and spray? How many gallons does it take for a typical driveway?

 

[AverageDad]

I buy bulk an its between 12.5% and 15%. You spray it to just cover/wet it, if it's running you sprayed too much. Pump sprayer is best method if you don't have commercial equipment. 10% stuff from lowes mixed 50/50 with water will work well. I use about 4 gallons for standard 2 car driveways.