Commercial Roof Clean, Large High School


Howdy all, I think this is the first time I popped in here since the convention but it was a pleasure to meet everyone! @squidskc was a great person to learn his methods to his madness from, @MrSparkleVA was way taller than I expected! Great people at that convention though. Anyways, landed a high school roof clean, 400,000 sq ft. Looking to see if anyone has a good way to keep their hoses off parapit walls when your unit is on the ground and your up top. I was going to build a contraption so the hose wouldn’t rub the walls and would run smoothly when pulling.
This will be my first multi level clean where I need to run my lines a good distance over the wall. Any pointers to tackle any obstacles I might hit? This is a EPDM roof (rubber like membrane), pretreating with detergent required by GC and surface cleaning into roof drains and overflow scuppers.


EPDM. Is often held together by a tape . Pressure will strip it off. Roof mix and a low pressure rince is usually all that’s needed. Even the ones with the vulkinised seems or melted seems can separate. It cleans up pretty quick though



What a job. I expect that you’ll rock with that job, and much more to come. I can only wish you the best of fortunes as you tackle this. You’re a stand-up dude, and your success seems imminent.

I know you haven’t already forgotten about Gus’s WORLD FAMOUS CHICKEN: fried green tomatoes, fried pickles, etc. Now, THAT was a photo opp that we missed, my brother.


Are the downspouts discharging to land scape or piped underground ? Look for parapet rollers for your hose guides [high rise equipment]. I see no mitigation ponds for piped runoff ? If there are, they are considered waters of the U.S & can receive no discharge. We have done a lot of very similar & rinse only when we have. I would not use a surface cleaner on any membrane type roof unless having a wavier or cleared by maintenance engineer. Congrats on landing a real money maker !


I’ve cleaned a few EPDM roofs. I don’t dare apply high pressure to this rubber membrane material. I shoot it with about a 2-3% mix let dwell till discoloration and have my guys brush it with medium-stiff-bristle push brooms then rinse.


I called the manufacturer about their recommended cleaning specs and they said under 1000 psi you should be safe. But it also depends on how well the roof was done. How quickly were you able to clean the epdm?


I’ve heard mixed reviews on under 1000 psi will be safe to use SC. If it’s more effective other ways then so be it just trying to be sure of my process


Thank you! I am doing the first walk through tomorrow morning and we start on wednesday. Im going to have to answer those questions tomorrow as I am unsure. I have it in my contract that I am not liable for faulty installation and they also are aware that there will most likely be some leaks. You spoke of parapet rollers for hose guides, any idea where I could find those?


JC Racestein ? CWC ? Its just a parapet clamp, edge roller with a guide. I cant remember where I bought them 25 years ago


Congrats :+1: Get a leaf blower if u don’t have one will save alot of time and keep drains from clogging. We use x100 blocks to pull hoses up then secure it. No need for SC cleans up easy let the chemical do the work .


I put a 50/50 mix on it then wash with a 15040 nozzle that is about 500 psi a 100x100 airplane hanger took about 2 hours maybe a little less it’s been a few years


Just did the initial walkthrough today, GC is not overly concerned with the pressure washing as the surface was not very dirty at all. Mainly need a good debris free surface for priming for the new roof membrane. Yeah I have 4 brooms, two 4GPMS, and a chemical cart that I made so I can tote more than 4 gallons of mix on my back. Ill shoot up some pics once we get underway on Thursday. Should go fairly quick is my hope


Not sure if I follow you on the blocks, what purpose are they serving for you?


Once you get your first hose over wall just tie it down to something so it doesnt move. Then add on how much more hose you need. You would be wise to duct tape around all your hose connects. Dragging them can puncture the rubber roof. Also any all purpose cleaner will be fine for that. Xjet m5 and 5 gal bucket would allow you to spray cleaner fast in big sections than just switch to green nozzle and rinse.
Epdm roofs are glued down so as long as your pointing down at the seams when washing you will be fine. Congrates on such a sweet job


These are the blocks I use they come in handy. Tie off the block drop down a tag line and pull the hose thru. Then tie off the hose. In Mills we use them alot.


I remember your lady asking for a Cab Sav and the waitress being like What?


Good luck Chris. Don’t forget to take a moment and film some of your work. It will be great advertising.


Good luck!! Watch out for critters,wasps,bees,and hornets!! Be surprised what u might find!!


Im going to be trying hard to but the work is for a large GC so alot more difficult to get drone shot and to do go pro as well


What is a GC?