Wood vs. Plastic Interior Window Treatments
Both wood and plastic can be successfully used in the manufacture of custom interior shutters and window shutters. The decision as to which material to use is based on the environment of the window shutters. The environmental factors that impact shutters in this decision are: heat and water.
Heat: Plastic is formed/shaped by heat. The blown PVC used in most plastic shutter components is formed at 160 degrees. Likewise, as temperatures in a window approach 120 degrees, plastic can begin to lose its rigidity. Hollow plastic louvers begin to lose their beam strength (ability to span even short lengths – you would call this warping – see picture above) at temperatures as low as 120 degrees.
MDF (Medium Density Fiberboard) or composite/vinyl/manmade – marketing terms used by our trade – can lose significant beam strength starting at 120 degrees. At 140 degrees it is very pliable. MDF is formed under pressure at approximately 140 degrees utilizing plastic resins, wax, and various materials. These materials include wood fiber, scrap, recycled paper, bamboo, carbon fibers and polymers, steel, glass, forest thinning and sawmill off-cuts.
Water: This is generally much less a factor. Wood as a tree is formed with water; a tree transports solids within itself by the movement of water. As a result, wood can be reformed with moisture; either deliberately, as in the process of steam bending wood or the production of paper, or inadvertently by subjecting wood to standing water on your window sill or subjecting it to long periods of high humidity – neither are terribly likely in your home. If so, you have greater problems than what may or may not be happening with your shutter.
Keep in mind; exterior storm or hurricane shutters, in use for generations, have historically been made from real wood. Properly sealed, wood is an ideal base material.
So the choice between wood shutters and plastic shutters is dependent upon your environment. Wood shutters can change shape under changes of moisture and plastic shutters can change shape under instances of heat. All windows covered with shutters undergo great extremes in heat, from 40 degrees by night to 150 degrees by day, but not all homes have such wild swings in moisture (measured in relative humidity). Most home’s relative humidity hovers in the 15% range, and wood shutters will maintain 7.2% moisture content in a 78 degree home. We use wood as our material of choice for shutters because it provides the best results for the largest group of homes (i.e. air conditioned) in the United States