Color changes/Ambering:
General Comments:
1) All uncoated, bare wood
and ALL oil-based polyurethane's get darker in color with
time. They darken less and at a slower rate when they
are exposed to light. Such as, under area rugs, furniture
and areas not exposed to light.
2) Ambering of water-based finishes varies widely however
as a general statement waterbased finishes are more color
stable than oil based finishes and therefore at a slower
rate.
The Problem:
The look of the floor has darkened non-uniformly over
time.
The Cause:
Since the wood itself and, sometimes, its topcoat are
darkening with time and light exposure, then any areas
of the floor covered with area rugs, furniture, etc. will
appear darker when uncovered. This is more pronounced
if an oil modified polyurethane finish is applied instead
of a non-yellowing or non-ambering water-based finish.
How to fix
the problem:
1) For an immediate remedy, completely re-sand (If applicable
re-stain) and re-coat the entire floor.
2) The condition is substantially but not completely reversible
with the passage of time. Removing the items that are
blocking the light will allow the previously unexposed,
darker areas to lighten and blend somewhat with the rest
of the floor. The blend is not perfect, however, because
the wood lacks the ability to "recover" fully.
How to avoid in the future:
Finishing with a non-ambering topcoat
will eliminate the darkening appearance contributed by
the finish. Protecting the wood from the bleaching effects
of sunlight is achieved only by minimizing sunlight infiltration
via drapes and ultraviolet (UV) light blocking windows.
UV light blockers in the finish cannot eliminate color
variability problems caused by sunlight.
Note:
This condition can occur on any floor but is more pronounced
the lighter the color of the floor.
