TIPS FOR EXTERIOR HOUSE PAINTING
Clean, dry and dull. Sounds boring I know but when it comes to exterior painting, those are the three most important words. Here's why...
Clean - Mildew is a common occurrence on home exteriors and if present, pressure washing will be necessary. The best thing to do is to pre-treat mildew with a 4:1 water to bleach solution which will effectively kill mildew spores. The solution can be applied with a garden pump sprayer and will help to prevent mildew from growing again. Once the solution has been sprayed on, wait 10-15 minutes before pressure-washing and take necessary precautions with any plants and/or flowers that may be in surrounding areas.
Dry - Painting exterior wood that's high in moisture, likely due to rain is never a good idea and can reduce the longevity of the paint. Flat surfaces by nature of their design will hold and absorb moisture far more readily than a vertical surface. Special attention must be paid to not prime or paint over top of these surfaces without allowing the wood to release most of the moisture. Generally, if the temperature is less than 15 C (60 F), a surface should be allowed 48 hours to dry before painting. If the average air temperature is 24 C (75 F), 24 hours should be allowed before priming and painting bare wood. When in doubt, give the wood an extra day to dry out.
Dull - Most high quality acrylic paints nowadays have good bonding properties when the surface is prepared properly. One area of particular concern when painting an exterior is the front door which is the focal point of any home's exterior. To ensure the new coating will bond properly to the old, ensure the door is "deglossed" before painting. The first step will be to wipe down the door with a TSP (Tri-Sodium Phosphate) solution. Then, using 120 Grit sandpaper, sand the entire surface of the door focusing around the push points on the door where most finger oils collect. If the door is still smooth or glossy, apply a bonding primer such as Sherwin Williams Multi-Purpose Latex Primer. Then apply a high quality 100% Acrylic Enamel to the door in the color of your choosing.