Siding and Trim



There may be wooden siding underneath the aluminum if you want to display the historic wooden exterior.

  • ♦  Consider this if your home is eligible for historic tax credits—there could be additional benefits to removing it.
  • ♦  Be sure to see Painting Wood Siding and Trim to properly prepare the transition of your home back to wood siding.


  • ♦  To retain the historic integrity of your home’s exterior, it is recommended to keep your wood siding and other historic fabric intact.
  • ♦  Wood siding creates a more authentic historic appearance.
  • ♦  Maintain the historic integrity of the building by retaining the historic materials.
  • ♦  When replacing damaged or rotten wood siding consider the following:
    • ◊  Should only the damaged section be removed to retain as much historic fabric as possible?
    • ◊  Will the replacement of a small piece look out of place?
    • ◊  Should the repair be extended to the entire board so it blends better?
    • ◊  Will the removal of an entire board damage the ones above and below, making for a larger project?

Always consider how even the smallest repair will affect the surrounding material.

  • ♦  Replacement wood for siding
    • ◊  Salvaged siding from architectural salvage yards
      • −  See Reuse of Building Materials
    • ◊  If buying new wood, purchase the best you can find/afford.
      • −  Focus on rot-resistant wood
        • Cedar—rot resistant, but needs special primer or paint may not stick, need stainless steel nails
        • Fir—good for exterior trim and siding
        • Yellow Pine—medium price, but quality can vary
        • Cypress—old growth is great, but new growth cypress will rot when used on exterior work
        • Hot dipped galvanized for woods other than Cedar
      • −  When hiring a woodworker or contractor, ask what type of wood he/she will be using for exterior work. Then do your homework.
    • ◊  Ensure the profile is an exact match to the original siding. Slight variations and sizes may not be noticeable until the new and old are next to each other.
    • ◊  Maintain the original reveal of the siding.
      • −  Reveal is how much of the board or siding is showing. It does not include what is lapped under the above board.
    • ◊  When installing new wooden siding:
      • −  Prime all six sides of the board—this will discourage any moisture from permeating the board.
        • If the back is left untreated, the board can distort after being exposed to the elements.
      • −  Option to consider—breathable primer.

Fiber cement board

  • ♦  Not a historic material, but may be offered by contractors.
  • ♦  The exterior surface of fiber cement board can be different from most historic wood siding, often more varied and not as smooth.
  • ♦  The increased weight of cement board should be considered when being placed on a historic frame building.
  • ♦  Can be a challenging material if not familiar with it. Nails cannot be overset or the board will be compromised—any damage to surface reduces the board’s integrity.
  • ♦  With respect to moisture issues, it has the same limitations as wood.
    • ◊  If wood is damaged because of its location and water problems, there will be the same issue with fiber cement boards.
    • ◊  Exposed surfaces – if material is cut, it must be primed or moisture can affect it.

Many other options for manufactured exterior siding are available; although not a historic material, they may be offered by contractors.

  • ♦  Boral brand, TruExterior
    • ◊  Fly-ash is enclosed within the board—could be exposed if board is cut.
    • ◊  Smoother profile and lighter weight than most fiber cement boards.

Preventative Care for Wood Siding

Inspect once a year—find small problems before they become LARGE

  • Look for cracks, gaps, splitting wood.
  • Pay close attention to vertical seams in siding.
    • Wood can expand and contract, cause cracking.
  • Consult a professional or conduct research to do repairs on your own.
    • Fill minor gaps and cracks with a acrylic/latex caulk.
      • Inspect caulk on a regular basis, particularly in areas of intense UV exposure.
    • Do not over-seal exterior siding. A building needs to breathe and you must allow for moisture to evaporate from behind the siding.
      • The underside of lapped siding allows for some breathability, do not caulk this opening.

To extend the life of a paint job:

  • Every 2 to 3 years, clean dirt and mildew from surface with a gently cleaner.
    • Do not power wash.
    • Better options for exterior materials:
      • Clean with diluted TSP
        • Information and precautions for cleaning with TSP, please read and use with care.

Clean with a 1:10 bleach to water solution.

If have a large mold or mildew problem it could be worth investigating the area.

  • Is there moisture coming up from the ground into the walls?
  • Is there evidence of moisture on the other side of the wall that can be seen from the inside?
  • Is the wood actually rotting?
  • Is there enough airflow behind the siding?

Inspect how water is being moved away from the building. When safe, stand outside in the rain and watch where water is traveling.

  • Water running over from a gutter? Causing damage at gutter as well as splash back on ground below?
  • Leaks in downspouts?
  • Splash back from a road or sidewalk (or gutter located above)?
  • Rising damp from poor drainage under the building?
  • How is water getting away from the building?
    • Downspouts
    • Sump pump drainage
  • All surfaces within six feet of the foundation should be sloped away from house at least a ¼” per foot.
  • Are the gutters sloped correctly?
  • Address these problems as well or you will find yourself redoing the repairs soon

Siding and Building Trim Materials

Trim Materials

Keep profile the same!


Think outside the home-improvement store box! Don’t feel limited to what you see on display in these stores. (Applies to wood trim as well as hardware and lighting options.)

There are great companies that sell unique profiles of molding and craftsmen that will replicate woodwork.

  • ♦  Some historic renovation construction companies will mill their own.

As with siding, cracks and gaps in wood trim can lead to larger problems with rot and deterioration.

  • ♦  Inspect accessible trim annually.
  • ♦  Hire a professional to inspect trim, such as the cornice, fascia, and soffit, on upper levels of building to ensure there are no gaps allowing in water, bugs, birds, or wildlife.

Finger-jointed pieces of trim are NOT appropriate for exterior work.

When replacing with a non-wood option:

  • ♦  Determine what district you live in—do you need ARB approval?
  • ♦  Changing from one material to another on the exterior of your home constitutes an “alteration” not a “repair” and generally requires a permit.

Painting Wood Siding and Trim

Preparing the surface

  • The possible presence of lead paint must be addressed. Contracted labor as well as homeowners should use proper safety precautions and appropriate removal methods for any lead-based paints.
    • Lead paint is very dangerous for small children.
  • If a large amount of paint is coming loose, the surface is uneven and in poor shape:
    • Old loose paint must be removed before a new coat of paint is applied.
      • If old peeling paint is left on and new paint is placed on top, it will only be as strong as the paint below it.
      • The new paint will expand and contract at a different rate than the old paint, causing it to fail.
    • Use a high-quality primer—not fast-drying latex primer, should use slow-drying oil primer.
    • Use high quality paint—two coats (depends on color of paint).
  • If surface was recently painted and in good condition but beginning to dull and wear thin:
    • Do not need to strip down to bare wood every time a building is painted.
    • Just clean wood and do a light sanding to prepare the surface.

Do it right the first time

  • Thorough preparation of the surfaces will result in a longer lasting paint job.
    • Completely removing old paint, sanding, and priming will extend the life of a paint job.
  • Quality paint is worth the investment.
    • But without proper surface preparation even quality paint will not last.
    • Cheap out on paint and you will find yourself painting again sooner than you should need to.
      • Virginia Paint & Decorating Centers—Helpful employees, quality products

  • A large part of the cost when painting a home is the labor, realize this going into the process.
    • Does the cheapest option have the experience, licenses, and skills you need?

Space out maintenance

  • Consider painting one façade or area (e.g., a porch) of your home each year. By doing it in phases, the cost will be spread out over time.

Proper temperature for paint application

  • Generally not lower than 55 degrees F.
    • The paint can may say otherwise, but attempt at your own risk.
    • Temp needs to stay at a good level until dry. What will the temperature be in 12 hours?
  • Be wary of painting in extreme heat.
    • Paint drying too quickly can be a problem as well.


Preservation Brief 8—Aluminum and Vinyl Siding on Historic Buildings by John H. Myers, revised by Gary L. Hume

Preservation Brief 10—Exterior Paint Problems on Historic Woodwork by Kay D. Weeks and David W. Look, AIA

Preservation Brief 16—The Use of Substitute Materials on Historic Building Exteriors by H. Ward Jandl

Preservation Brief 37 – Appropriate Methods for Reducing Lead-Paint Hazards in Historic Housing by Sharon C. Park, FAIA, and Douglas C. Hicks

Preservation Brief 47—Maintaining the Exterior of Small and Medium Size Historic Buildings by Sharon C. Park, AIA

Vinyl vs. Wood Siding your House—The Old House Guy

Benjamin Moore Paints—Historical Collection

Benjamin Moore Paints—Williamsburg Color Collection