I recently got a job to pressure wash the river rock sidewalks of 8 condo buildings. Walks are 6′ wide. It comes to about 16,000 sq. ft. or 2000 per building. I gave them a ball park but am trying to figure out how many sq. ft. I can wash in an about an hour. The river rock is tight and in good shape but the existing sealer has “clouded” over time.
Any one with experience here know roughly how many feet I can do in an hour as a cleaning procedure before applying the sealer? I”m assuming it would take slightly longer than washing flat concrete.
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Could be a tough one depending on the type of sealer and how porous the rock is. Reminds me of some brickwork I had to clean ........... painter spatters that had been there for years. Pressure washer, paint stripper, muriatic acid .......... and a ton of elbow grease before it looked acceptable. May be a piece o' cake but I'd be inclined to try a section first, just to see what you're in for.
Well, the rock is pretty clean, espeically now that we're in our rainy season (Naples, FL) with about a hour rain each afternoon, so it's kept pretty clean, except for residual mildew, and sporatic spots of fungus. The main reason for the pressure wash is to remove soil that's worked down between the rocks and possible reduce of of that cloudiness on the old sealer.
I'm thinking maybe I can do one building - 2000 S.F. - in about 4 hours or roughly 500 s.f. per hour. Since the walks are about 6' wide, that's about 85 lin. ft. per hour. That would allow for moving around when changing to a different hose bib location.
Sound plausible?
Then before we actually apply the sealer, I'll lightly use a blower to remove any debris from the previous day of washing. We'll use a sprayer for the sealer using a few sheets of 1/8" luan cut to 16" high by 96" long against the stucco walls as protection. We're going to use Chatahoochee (sp?) sealer.
Sounds reasonable to me- two people would work well; one with a bleach solution and a scrub brush and the other following up with a pressure washer. I've never used that brand of sealer before so I did a little checkin' http://www.anvilpaints.com/products/1950.html If this is the stuff, it sounds like moisture may cause the cloudiness problem and those daily rains may be a problem with the application of the new sealer .......... hope not. Thanks for all your past posts- I've learned much.
Thanks for your help. One guy will go ahead of me and hit the heavy mildew and fungus before the washing. That sealer was suggested to me by a guy who does that stuff for condos full time and he gets it from Home Depot - $50 per five gallon pail. I'll check on it's sensitity to moisture. In fact, I'll call the manufacture direct. It dries in about an hour so I figure we'll do the sealing in the AM, after the dew has dried and before the rains hit; we'll switch to washing the next bldg.
Funny, I was thinking of buying a washer for my own house, driveway, etc., but said: "Nah. I'll rent one went I need it." True to form for most contractors, I now have an "excuse" to buy one and charge 1/2 of it to this job.
I played it save and figured the sealer at about 100 s. ft. per gallon. Soooo, I gave them a ballpark of $7300 give or take $500, with sealing, which will go twice as fast as the washing. Fortunately for me, even though my labor rate is almost double my competitors, the lady manager said: "I know you're not cheap, but I also know you'll do it right." Guess I should have kissed her rear end.
Now I'm comfortabe with that ball park. And again, thanks for your help.