Take Care of Your Wooden Interior Door


  • Do not subject doors to extreme heat, dryness or humidity. Wood will warp when exposed to these factors.
  • Store wooden doors inside, on a flat, level surface in a dry, well-ventilated building and always keep them covered. Following these instructions will prevent shape and color distortion of your custom millwork.
  • Allow doors to reach room temperature and stabilize 24 hours before installing. This allows for the humidity levels within the wood to acclimate with the new surroundings. 
  • Remove film from French doors with caution. The tempered glass is sensitive and could scratch by using sharp objects or abrasive cleaners.

Understanding Humidity

Wood absorbs and loses moisture to balance its moisture content to the humidity and temperature of the air.  This caused wood to expand and contract as the moisture level changes; however it does not contract or swell equally in all directions.  The thickness and width of lumber is more prone to the effects of moisture and climate change rather than insignificant changes in length.  These effects fluctuate from one species to another

  • Proper humidity levels in the range of 35% to 50% should be maintained throughout site storage, installation and use.
  • The density of the wood can affect the extent of the expansion and contraction.  Choose a wood species with a lower dimension change coefficient for homes in high risk areas.
  • Severe dryness or excessive moisture will cause problems in panel contraction or expansion, joint separation, veneer checking or cracking, bowing, contraction or expansion of the stile or rail.
  • Product failure or product concerns related to exposure to extreme changes in temperature or humidity is not covered under the warranty.
  • No matter the location, products installed into non-air conditioned or humidity-controlled homes will expand.  Seasonal homes should always be maintained with some type of climate control during off season or non-use.
  • Natural expansion and contraction of a wood door can cause noticeable seams.  These unavoidable seams are a natural characteristic of an applied paint finish and are not covered under the warranty.
  • Proper finishing will slow the absorption of moisture, but will not eliminate it.  Doors should be completely finished on all faces and sides as soon as possible in accordance with the “Finishing” instructions. 


Because we use genuine wooden products, the color and wood grain are unique to your interior door. Some of these markings will become more pronounced during the wood finishing process.  Woodport is not responsible for these variations. Please direct all questions regarding the proper application of sealers and finishes to your chosen finish supplier.


There is a step-by-step process to prepare your interior door before installing it: Sand, stain and finish


  • Sand lightly with fine-grit sandpaper (180-220). Sand "with the grain" to avoid scratches.
  • After sanding, clean the door with a soft cotton or fiber cloth to remove any debris.
  • Pay special attention to handling marks, raised grain and other blemishes. 
  • Sand slightly more for dark stains, high gloss paints and spray finishes. 


A sanding sealer, otherwise known as pre-stain, is recommended to avoid a “blotchy” finish. For best results choose the same manufacturer for your sanding sealer, stain, and topcoat.  Sanding sealer is not necessary if only a topcoat is being applied.

  • Apply a thin coat of sanding sealer (or pre-stain) for a uniform appearance.
  • Test for stain compatibility in a discreet area as some wood types do not react well to particular finishes.
  • Notify the finish supplier if you detect an undesirable appearance and discontinue the finishing process until a solution is found. 

Apply the finishing products by following the instructions supplied by the manufacturer.

  • A clear finish for lighter wood types like maple and birch is recommended. The natural characteristics of these wood types may make dark finishes appear uneven.
  • Allow for adequate drying time after each coat is applied to confirm smoothness and color are correct.
  • Seal all exposed wood surfaces with every coat, including the top and bottom.
  • When staining the door, oil-based sealers work best for finishing. If painting the door, be sure to use a primer first. Water-based coats may highlight joints and raise wood grain.

Woodport is not responsible for the overall appearance of the finish applied.