New Cedar Siding
New cedar siding should be protected from the weather at all times.
Don’t leave the siding exposed to the elements - get the finish on as
soon as possible. It is usually not necessary to perform extensive
surface preparation as long as the siding has not weathered for more
than two weeks and is clean and dry. Any contamination, such as dirt,
oil, and other foreign substances, must be removed.
For smooth, flat-grained cedar, some surface preparation may be
needed. The surface should be lightly scuffed with 50-60 grit
sandpaper. This will greatly increase the performance of the finish
and will not detract from a smooth look. Surface preparation is not
necessary for textured cedar.
Weathered Cedar Siding
Weathered siding that has been exposed to the elements for longer
than 2 weeks may have a degraded surface that is unsuitable for
staining or painting. Prepare the surface by sanding, brushing, and
washing before applying the finish.
Paint Finishes for Cedar Siding
Paint must be removed if the old surface is severely peeled,
blistered, or if checking (small cracks) are present. Paint removal is
also necessary if a penetrating stain or water-repellent finish is to
be applied.
Changing from a painted surface to a wood stain can be quite
difficult. Paint usually penetrates the surface by a slight amount,
and this can prevent the absorption of stain. The end result will look
blotchy and in some cases, the stain will not penetrate at all. If the
surface is currently painted, it’s best to stay with paint instead of
trying to switch to stain.
Finishes can be removed by sanding, wet sandblasting, pressurized
water spray, electrically heated paint removers and chemicals.
Although quick and easy, sandblasting and pressurized water spray are
not recommended unless extreme care is taken to avoid damage to the
wood’s surface. The high pressure can easily remove sections of the
surface and ruin the siding. If the old paint is lead-based, it can be
quite hazardous to remove and special procedures must be taken. In
this case, it is best to hire a contractor that specializes in lead
paint removal to do the job.
Weathered Water-Repellent Finishes for Cedar
Siding
Weathered water-repellent preservative finishes should be cleaned
with a new bristle brush to remove loose fibers and dirt. If the
surface is soiled, it may be scrubbed with a mild detergent solution.
The surface should be thoroughly rinsed and allowed to dry completely
before refinishing. If mildew is present, use a product that is
specifically designed for the purpose. Be careful - Never mix bleach
with any product that contains ammonia as the fumes can be harmful or
fatal.
Weathered Penetrating Cedar Siding Stains
Weathered penetrating stains are relatively easy to refinish.
Excessive scraping or sanding is not required. A stiff, new bristle
brush may be used to remove surface dirt, dust and loose wood fibers
before applying the stain.