How to Troubleshoot Exterior-Paint Problems

Exterior paint is subjected to extremes in temperature, air pollution, expansion and contraction of building materials, mold growth and a host of other problems related to improper preparation and application. Understanding the causes of failure can help you correct an existing problem or avoid one in the future. (See also How to Troubleshoot Interior-Paint Problems.)

Difficulty: Easy

Instructions

1. To prevent mildew, wash affected surfaces with a 1-to-3 solution of bleach and water, wait 15 minutes and rinse well. Cut tree branches within 15 feet of the house. Use mildew-proof paint or paint that contains a mildew-cide additive.

2. To prevent or treat rust staining, sand the rust off of nail heads and countersink the nails. Dab water repellent into holes and spot-prime nail heads. Fill the hole with exterior latex or siliconized-acrylic caulk.

3. Tannin staining (brown stains on painted wood) can be treated by resoling interior mildew issues first. Then, apply an alkyd-based primer or top-quality acrylic-latex primer. Finally, topcoat with two applications of 100 percent acrylic-latex paint

4. For treating chalking, remove the chalk with a stiff brush and water or a house-washing solution, and rinse well. If chalking is still present, apply a primer and repaint.

5. If your paint is alligatoring (cracks in the paint resembling alligator skin), remove all of the paint down to bare wood. Apply a primer and one or two topcoats of paint.

6. If the house is peeling or bubbling, pressure wash the exterior before painting. Scrape it clean and use a wire brush or sand to remove all poorly adhered paint. Apply a primer to bare spots and repaint.

[MikeyJ]

on 3/7/2008 Wood siding, are similar to sidings made from fibre cement and vinyl and should never be power washed. The purpose of all sidings is to defend the structural wood frame of the structure from the elements, namely rain, wind and snow. Anything that would compromise that design concept should be avoided. The sidings, the building paper behind the sidings, and the flashing details are all designed to resist rainwater falling under gravity (15 PSI) with maybe a wind component. No siding installation is designed for someone to stand on the ground and fire water upward at thousands of PSI, and against all those elements installed precisely to prevent water, that falls from the sky, from intruding behind the siding. The wood sheathings and framing lumber used to construct homes are not naturally resistant to decay. Water forced into wall cavities encourage decay and mold. Pressure washing wood s