Miscellaneous Siding Issues

Cleaning Vinyl Siding
Vinyl siding resists most common household stains, but it will
become dirty like any product exposed to atmospheric
conditions. In areas not exposed to direct sun and rain,
periodic washing with a soft bristle brush and clean water
from a garden hose may be necessary to remove surface dirt.
Chalk may also accumulate on the surface. This is a normal
condition for pigmented materials exposed to the elements.
For the best appearance, clean vinyl siding at least once a
year.
To remove soil, grime and chalk from siding, use a garden
hose, a soft bristle brush, and a bucket of soapy water. (You
can also use the solution described below in the section
dealing with mildew.) To minimize streaking, wash the
house from the bottom up.
Thoroughly rinse the siding with clean water from a garden
hose. Avoid prolonged or high pressure rinsing of open
ventilated areas. Keep cleaning solution off surrounding
fixtures and surfaces not scheduled for washing.
NOTE: We do not recommend power washing vinyl or
polymer siding as it can cause moisture intrusion,
damage, and/or discoloration.
Stubborn stains
If you can’t remove especially stubborn stains using normal
household detergents, request a cleaner from your siding
contractor or your local building materials retailer. Always test
any cleaner on an inconspicuous area before full use.
Mildew
Mildew may be a problem in some areas, especially warmer
climates with consistently high humidity. Mildew appears as
black spots on surface dirt and is usually detected in areas not
subjected to rainfall, such as under eaves and porch
enclosures. To remove mildew, prepare a solution as follows:
1/2 cup detergent (Tide, for example)
2/3 cup trisodium phosphate (Soilax, for example)
1 quart 5% sodium hypochlorite (Chlorox, for example)
3 quarts water
CAUTION: Greater concentration may cause damage to
the siding and soffit.
If the above solution does not readily remove mildew spots,
ask your siding contractor or your local building materials
retailer for a mildew cleaner.
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CertainTeed Vinyl Siding Installation Guide
SECTION 11 – Miscellaneous
Siding over Asbestos
Vinyl siding retrofit over asbestos
This is a recommendation from the Vinyl Siding Institute after
discussions with Federal EPA officials. Because local
regulations supersede federal regulations, local EPA officials
should be contacted in the area where the work is being done.
The most desirable practice is not to disturb the existing
siding on the home. Apply sheathing over the existing
asbestos siding, and then apply vinyl siding over the top of the
sheathing. The sheathing will serve to flatten the wall and also
retain any breakage of the cement asbestos siding. Nails
should be long enough to penetrate through the sheathing
and existing asbestos siding and into the wall studs.
If there is a need to level or flatten a wall, apply furring strips
over the sheathing.
In the case where the homeowner wants the existing cement
asbestos siding removed completely, removal should be done
by a professionally trained asbestos removal crew.
Please note that some jurisdictions require all asbestos
removal to be performed by a trained asbestos removal crew.
Historic Restoration
Vinyl Siding Institute recommended guidelines
If a building is in an historic area or has been designated an
historic building, be certain that approval for the use of vinyl
siding has been obtained from the local historic society. This
applies to building additions as well.
Before proceeding to re-side an historic building, the building
should be examined for moisture, insect infestation, structural
defects and other problems which may be present. These
problems should be addressed and the building pronounced
“healthy” before re-siding with any material.

Do not damage or remove the original siding. If at all possible,
do not alter the original structure so that the application of
vinyl siding is reversible (i.e. the original would remain intact
and some time in the future, if desired, the vinyl siding could
be removed). Exception: “In cases where a non-historic
artificial siding has been applied to a building, the removal of
such a siding before the application of vinyl siding would, in
most cases, be acceptable.” (Preservation Briefs, Number 8 -
U.S. Dept. of the Interior - 1984)

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CertainTeed Vinyl Siding Installation Guide

Exercise every care to retain architectural details wherever
possible. Do not remove, cover, or add details until you have
the building owner’s written approval. Determine that the
owner has consulted the local historic society regarding the
foregoing.

Use siding which closely approximates the appearance of the
original siding in color, size and style.

For More Information

These instructions will enable you to successfully complete a
siding, soffit, or porch ceiling installation. However, no set of
instructions can answer every question or problem that might
come up during a project. So if you are in doubt about how to
complete a specific procedure, we suggest you try two
avenues of help:

First, call or visit your building materials supplier. You should
be able to find someone with the know-how and experience to
answer your question or solve your problem.

Second, if you need additional help, call us at 1-800-233-8990.
Our Sales Support Group is always ready to help you.

This installation manual is updated periodically. The most
current information will always be posted on our website:
www.certainteed.com.