4 to 8 hours for an average size house with 10% to 20% of the surface area requiring scraping
- Lead testing kit (if house is pre-1978)
- Elbow grease
Scraping the loose paint off a house prior to priming and painting is an important step in the process. Peeling paint does not provide a sound surface for new paint to adhere to, so it must come off if you’re going to paint your house right!
WARNING: If your house is pre-1978, buy a lead-testing kit. It the results are positive, consult with an expert. Never scrape or sand lead paint without proper training!
Scraping, hard as it is, is actually one of my favorite parts of the house painting process. It has a spiritual monotony and physical grind I find appealing. Most houses don’t require much scraping, of course, and some none at all. Ideally, paint should never be allowed to deteriorate to the point of actually peeling, because at that point the fundamental structure of the house is nakedly exposed to the elements and damage can occur very quickly. But sometimes for one reason or another people let their house go; sometimes it gets totally out of control, with entire sides peeling top to bottom. It’s a chore scraping houses like that, but if you get in the “zone” and keep moving along, you can get it done.
Granted, you need to know a few tricks to achieve scraping nirvana. First, realize your most important tool is a radio. You can use a boom box if you want, but I recommend a Sony Walkman radio with headphones that sells for about $15 at Kmart. It is compact and feather-light and you won’t have to worry about destroying your precious iPod or smartphone (a distinct possibility). The muse of the radio goes better with painting anyway, so get the Walkman. Dangle the cord behind your back so it doesn’t get in the way. And forget that belt-clip it comes with, just slide the radio into your back pocket.
Now you’re ready to scrape. Beyond the radio, you need only a few basic tools. One should be a stout scraper with a sharp blade. The blade should be 2 1/2 to 3 inches wide and two-sided so it can be reversed when the blade on one side gets dull. When both sides get dull, replace the blade or sharpen it with a file. Never waste your time scraping with a dull blade.
In addition to this large scraper, you should have a smaller scraper of the same design with a 1-inch blade. This will help get into tight corners. It also helps to carry a flexible (not stiff) putty knife with a one-inch-wide blade; this can be used to slide under and lift up the edge of peeling paint when the bigger scrapers can’t seem to grab it.
Finally, a stout multipurpose painters’ tool is always a good thing to carry along; I like the kind with the hammer-head bottom on the handle so I can pound in any emerging nails before I scrape a section. You don’t want your scraper running over nails.
As far as the actual scraping itself goes, the goal is to remove any paint that is no longer bonding to the surface. If it’s still adhering, it can stay; in fact will be impossible to remove unless you dig the scraper into the wood to the point of damaging the siding.
When you scrape, make your strokes consistent with the natural “direction” of the siding. In the case of wood, this usually means going with the grain. Do most of your scraping with the grain while applying a fair amount of pressure, sometimes even using two hands on the handle; then do a very light scrape against the grain to get the edges that didn’t get caught when you went with the grain. Finally, use the putty knife to “clean up” any recalcitrant edges that persist. Once there are no more edges of peeling paint sticking up, move on to the next section.
The main issue some people have with scraping is that it results in a “cratered” effect on the surface wherever the peeling paint stopped peeling and started adhering. This is especially noticeable on smooth, lapboard-wood siding. If you use a low-luster paint, it’s hard to see these depressions from the sidewalk, but if you get up close you can see them and it bothers some people. If you are one of those people it bothers, you have two choices: Hire a contractor to completely remove all the old paint, or use a “siding spackle” to fill the craters and then sand them smooth.
The first option—complete paint removal—isn’t really something you can do yourself. The various methods—chemical stripping, sandblasting, belt-sanding, or combinations thereof—are nasty, brutish, and never short. If you want to go that route, hire a contractor who specializes in restorations. Using siding spackle, on the other hand, is something you can do yourself if those craters are really going to keep you awake at night. Ask at the paint store for an exterior-grade filler that dries hard and is meant to withstand the elements. Purchase a variety of putty knives to apply the filler to the siding (2-inch, 4-inch, and 6-inch should cover it). Fill in the craters with smooth swipes of the knife, trying not to goop on too much spackle because that’s just more you’ll have to sand off—but at the same time realize the spackle will usually shrink a little when it dries so you need to account for that.
After it’s dry (give it at least 24 hours since most good exterior-grade spackle is oil-based), start sanding it with an orbital or vibrating palm-sander and sixty- or eighty-grit sandpaper. Wear a dust mask. The radio won’t help you here because you won’t be able to hear it over the sander, so get ready for some serious tedium.
I’ve seen people practically reconstruct a whole side of a house using this method, and it looks okay if it’s done properly, but it is time-consuming and labor-intensive. As such, if you choose this method of cosmetic repair (and keep in mind that’s all it is), my advice is to focus on highly visible areas, i.e. the front side of the house and around commonly used doorways. If you find yourself spackling the back side of the garage, please consult a licensed therapist to help you deal with your neuroses.