Please help me to not damage myself...

December 17, 2007 6:58 AM

Barely competent homeowner question about siding and power washing.

I received a letter from the homeowner association the other day telling me that I need to power wash the siding of my house because of mold. I went out and looked, and sure enough on the second story on the east side of the house it looks very dirty. I assume all the dark areas are mold or mildew showing up on the white vinyl siding.

I have never used a power washer before. I don't know what kind of range they have. Would I be able to rent a power washer, stand on the ground, and clean away all of the dirt and mildew on the second story of the house? Would doing it from the ground cause a problem with the water getting up underneath the siding? I am more than a little apprehensive about trying to do it from a ladder, physics being what they are. I have no desire to pull the trigger on the power washer and find myself plummeting fifteen feet to the ground from the kickback.

Any advice on how to safely and properly deal with this?

posted by Lokheed to home & garden (8 comments total)

I get mold on the north side of my vinyl sided house due to it being very close to some trees, and lack of sunlight. All I do is wash it with a soapy stiff brush, and rinse it with a garden hose. I would avoid using a power washer with vinyl siding. If you hit a seam at the wrong angle, you can tear it off the house, or get water inside, which creates aditional problems. Good old fashioned 'Elbow grease" is the best method, IMHO.
posted by lobstah at 7:34 AM on December 17, 2007

Yes, the problem lies in getting water under the siding, where it isn't meant to be. Especially with vinyl siding, it will take a long time to dry out from under there and could cause other problems.

Power washing is not strictly necessary. You could get up on a ladder, wash the area with a sponge and a bucket of water with a few cups of bleach in it, and then hose it all down with a garden hose. I think that's what I'd do; I have done this with painted wooden siding, no problem. You might even try starting with a hose attachment (like they making for spraying stuff on your garden) that can spray a water/bleach mix up, and then rinsing that off, it might do the trick.

If this area is very shady or crowded in by trees, it might be a good idea to cut back vegetation, let a little sunlight at it, which will help slow it down.
posted by beagle at 7:39 AM on December 17, 2007

There are services for hire that can take care of this and there are extension wands for power washers. Use a narrow spray pattern to keep up pressure and be more precise with the areas you hit. You might also consider using a cleaning solution in the washer's reservoir. If you haven't any plants that might be damaged in the process, pre-treating with a bleach solution might help, too. I brush off what I can beforehand and use the washer mostly for the worst areas and a good, gentle rinse. At least, I did, when I owned a home.

If you rent a washer, the folks at the store will be able to give more advice for their particular models.
posted by bonobo at 7:39 AM on December 17, 2007

Home Depot and the like sell house wash that sprays on with a garden house for dirt and mildew issues. I've had pretty good results with the stuff so I would start there.

A commercial grade pressure washer can do serious damage to your siding or paint job. You don't mention the size of the house, but I live in a fairly expensive part of the country and I could hire a professional to do my house for a couple of hundred bucks. If the house wash doesn't work I'd probably bring in the professional and not risk the damage to the house or myself.

Just make sure you are hiring somebody who is insured, bonded and does pressure washing as a major part of their business. Any yahoo with a pick up truck can buy a pressure washer and a magnetic sign for their truck.
posted by COD at 7:40 AM on December 17, 2007

You can easily use a power washer on vinyl siding. Use a fairly broad tip. (I pre-spray with a light bleach solution for the mold, using a garden sprayer.) As for your concern about doing it from a ladder: don't worry. Test the "kick" while on the ground so you'll know what to expect, but it won't be bad. My dad was a house painter, and he had me doing this from a ladder when I was just 13 years old. Good luck!
posted by unclejeffy at 7:41 AM on December 17, 2007

To clarify: I do own a commercial power washer, and I have used it on a ladder to take the fuzz off cedar shingles. Besides the 'kick" most of those rentals leak in one form or another. Add the sprayback to that, and it can become treacherous ...especially if you are uncomfortable on a ladder. I still maintain that you use a brush and water, or hire a pro to do it.
posted by lobstah at 7:54 AM on December 17, 2007

I 'powerwash' my vinyl siding with my hose. I bought a large (1/2 or 5/8 in.) diameter hose, crank the water all the way on, and use a good brass hose nozzle. It doesn't get all the mildew, but I don't have an association. If you have this type of attachment, you could spray on some 1:4 bleach:water solution, and let it sit overnight.
posted by theora55 at 8:59 AM on December 17, 2007

The stuff you want is tri-sodium phosphate, or TSP. Look for it at the local hardware store. Spray or soap it on with a sponge, wait a half hour, and hit it with the garden hose. If that doesn't work, a rented pressure washer will work fine without going through the siding. Nothing I've been able to rent has been able to make a dent in my siding. It's the heavy-duty commercial ones that can be a handful.
posted by idiotking at 9:20 PM on December 17, 2007