Wood
with the appearance of severe mildew but will not lighten when tested
with bleach. Darkening and decaying wood generally has a more solid,
consistent appearance.
POSSIBLE CAUSE
Darkening of wood
is caused by ultraviolet radiation. This is take place on wood that has
never been coated with a protective coating. It also can occur under
clear varnishes and lightly pigmented stains. Different degrees of
darkening can occur on different woods. If moisture penetrates into the
wood, varnish coating will peel due to wood decomposition under the
coating. Woods that are exposed to weather are not protected against
wood-destroying organism. Eventually the wood decays and ceases to be a
coat able surface.
SOLUTION
New woods
should not be exposed to weathering for extended time periods. Paint
and stain performance is best achieved when the new surface is coated
before installation or immediately after installation.
If
a wood surface is allowed to weather, the wood should be sanded to a
fresh surface before priming. Wood that cannot be sanded to fresh wood
must be replaced.]
Coatings can be applied to treated
woods after the moisture content has dropped to a paint able level-
usually 15 % or below. To determine if the surface is waterproof,
splash becomes noticeably darker, the surface is not waterproof. This
test is specially recommended for pressure- treated wood and smooth
cater. It is crucial to insure proper penetration of the coating.
SYSTEM
EXTERIOR
Primer, if needed A-100 Exterior Primer
Caulk Pro Select 1550A, 1230A, 1100A, or Window & Door
Finish Refer to our Exterior Paint Rating Chart to determine which product best fits your needs.
