Sometimes just looking at the
paint on your exterior will not show any signs of the paint getting old. Get a
little closer and run your finger tips along the wall and see what shows up. If
there is a chalky residue on your finger tips it may be time to paint. If there
is a light chalky residue pressure cleaning will remove most of it and a new
paint finish can be delayed for now. If the chalk is medium to heavy it is time
to paint, but not so fast there a few very important things to know and do
prior to painting.
First, what is chalk? Chalk is a natural
process of paint as it erodes from the sun, wind and rain. The binder in the
paint degrades over time and the paint pigment rises to the top leaving a
chalky residue. Depending on the quality of the paint will determine how long
the finish will last. Quality paint will last much
longer especially if a primer was applied prior to painting.
Next, chalk must be removed to ensure proper paint adhesion. If your up for the task and your in good physical shape its time to pressure
clean the exterior with a 1500 to 2500 psi pressure washer using a 25 degree
tip/ nozzle. Ware the proper eye protection and clothing during this process.
Note: Homes built prior to 1978 may contain lead based paint. The dust or fumes
created by cleaning, sanding or disturbing these surfaces can lead to adverse
health effects in children and pregnant women. For more information please call
National Lead Information Center at 1-800-424 LEAD.
While pressure cleaning, keep your pressure gun moving at an even pace.
Concentrating on an area for too long will scar the area or remove the paint.
Start cleaning at the top and go side to side, steadily reaching the bottom of
your exterior walls. If there's areas which are hard to reach there are extensions which can be attached to the end of the pressure gun. The mixture of chalk and water will produce a milky color
and will become clearer as the washing continues.. It can’t hurt to go over the
area a second time to ensure proper cleaning.
Note: Before pressure cleaning close all windows and doors. Move items
that are close to the home so they will not fly into you during cleaning. Do
not get to close to the windows while cleaning. If there are metal or plastic
soffits try to keep the pressure off these areas; they tend to bend or displace
the sections and sometimes damage these areas. Getting to close to wooden areas
will scar the wood.
Window, doors and rooms which have screens be careful not to get to close to these areas, it will cut into the screens. Most important do not point pressure gun at any part of your body.
Window, doors and rooms which have screens be careful not to get to close to these areas, it will cut into the screens. Most important do not point pressure gun at any part of your body.
Once the pressure cleaning is completed wait for the exterior to dry at
least a full day. Wipe your fingers across the walls at several areas of the
exterior and check if there is any chalk left. If there is chalk, is it light
or heavy? If it’s heavy the exterior will need another washing. If the chalk is
light a bonding primer should be applied to ensure proper adhesion of the
paint.
There are several products which work very
well to give your exterior a sound surface to apply paint. Depending on what
type of exterior surface you’ll be painting will determine the binding primer
to use. Bonding additives such as Emulsa Bond can be used on wood and masonry. Oil
base primers can be used on many types of substrates. Water base 100% acrylic
emulsion conditioners are also very good for stucco or masonry substrates. Remember
to ask for products that work well with mild to medium chalk.
Follow the directions for the product which best suits your situation.
Once completed, this vital procedure will create a proper surface for your
paint and one which will keep your home exterior finish lasting for years.
