Mistakes to Avoid When Painting the Outside of Your House

A man painting the outside of his house.

The weather's good, so it's nice to be outside. The kids are out of school, so you have a ready-made crew. Summer is a popular time to paint the outside of your house, and if you're a diligent do-it-yourselfer it's a project you can tackle in a weekend (or maybe a long weekend). But every summer, DIY house painters make the same mistakes when they take on this task. Don't be one of them.

Look Out for Lead

If you're painting a structure built before 1979, it is likely covered with at least one coat of lead-based paint. Lead-based paint is very dangerous, and can cause health problems, including brain damage. Special EPA regulations are in place regarding lead paint, such as taking a course before working on a structure containing lead-based paint. Test kits for your home are sold at hardware and paint stores. Check under the final coat of paint to see if there is lead in the older layers. Information on working on lead-based paint structures is available online. You can also get information at your paint store concerning location, cost, and duration of the required course. There are stiff fines for working on a lead-based paint house without taking the EPA required course.

Use the Proper Paint

Mistakes to Avoid When Painting the Outside of Your House

The most common mistake made in painting the exterior of your house is to use the wrong paint. If the existing paint on the house is oil-based, you must use oil-based paint to repaint the structure. If the paint is latex or water-based paint, you need latex paint. It is easy to find out which base the existing paint is. All you have to do is wet a rag with denatured alcohol and rub the surface. If it's latex, some of the paint will rub off onto the rag. Also, there may be different base paints on various areas. Check siding, windows, doors and trim separately. Using the wrong type of paint can result in catastrophic paint failure. There will be a lot of peeling if you get it wrong.

Clean Your House

Mistakes to Avoid When Painting the Outside of Your House

Another common mistake is to paint over a dirty surface. If possible, use a power washer on the surfaces to be painted. Power washers can clean your home with detergent, and then rinse it off. Before power washing, remove storm windows and screens so that the windows are washed. If you don't own a power washer, you can rent one. At the very least, the structure should be hosed down with a garden hose and scrubbed with a car cleaning brush on an extension pole. Allow one or two days for the house to dry completely before priming or caulking.

Take Time to Prep

Mistakes to Avoid When Painting the Outside of Your House

Now that you have determined the type of paint on your home and cleaned it, you are ready to start the paint preparation. One of the biggest mistakes you can make is not spending enough time on preparation. It is about 80 percent of a good house painting job. Use a triangle scraper to remove any loose or peeling paint, and sand the area with 120 grit sandpaper. All bare wood or siding spots need to be primed with an exterior oil base primer/sealer. Prime the bare areas as you scrape and sand them since it's a bad mistake to leave the sanded areas covered with dust. Carry a dry paint brush to use as a dust brush, and wipe the area with a tack rag. (You can buy tack rags at your paint or hardware store.) Prime bare spots with the primer/sealer after thoroughly wiping all the dust off. Use a paint can with about an inch of paint in it, and put the brush right in the paint. Never paint from a full can of paint and rest the brush on the side. This is a simple but serious error. The brush will dry out and also drip paint down the side of the paint can--a sloppy situation.

Caulk the Cracks

Mistakes to Avoid When Painting the Outside of Your House

You should caulk all cracks and holes with a good grade silicone caulk. First, use the tip of your triangle scraper to pull out any old caulk. Then, run a thin bead of caulk and smooth it out with your finger. It's a good idea to carry a bucket with some clean water to dip your finger in, and then wipe it clean with a rag. Otherwise, the caulk will build up and dry on your finger. A big mistake is to not caulk cracks that are not readily seen, such as under a first floor windowsill. Moisture will seep in, and eventually rot wooden windowsills.

Use Your Ladder Wisely

Mistakes to Avoid When Painting the Outside of Your House

Another error deals with the placement of extension ladders. Place the top tips of the ladder under the high points of the siding. Do not put the ladder tips on the raised areas because you will damage them. This is particularly important if your house has aluminum or vinyl siding. The tip of the ladder on the high area will put a dent in the siding. A good investment is ladder mitts, which are soft tips for the top of the extension ladder. And, of course, for safety you should always have an assistant hold the bottom of an extension ladder to keep it from falling.

Don't Rush

Finally, do not try to save time by applying only one coat of paint. Exteriors need two coats of paint. And don’t paint in direct sunlight because the paint will dry too fast, making it impossible to work with.