Tannin Bleeding Problem Solved

Sometime we encounter siding on homes that have a problem with splotchy looking brown or grey color that seems to appear as the home ages.  Going back over those areas with latex paint will not solve the problem.  A few years later and it will be back.  I’ve seen this occur on Masonite siding and of course on cedar siding.  On cedar siding usually it is caused from tannic acid bleed though. You will see this bleed through especially where there are knots in the wood.

The binders and resin in particle board that makes up masonite siding can make their way to the surface also. These binders and resins can migrate through the latex paint causing an unsightly splotchy look on any home plagued by this not so common problem.

Solution:

I have found through my many years in this business that a high grade of oil base primer can seal off this bleed though problems in both types of siding.  Latex primer doesn’t do the job.  So don’t expect very good results with latex primers.

Oil base primer can be painted over with a latex paint, but remember you can not paint over oil base paint with latex paint. It will peel.  The sheen of oil base paint prevents latex paint from forming a good boned.  However, since oil base primer has no sheen, latex paint will bond well to it.

Nicky Taylor

Owner