Sadly, because plywood products are not nearly as high quality as in the past, plywood manufacturers use a technique to disguise the common blemishes found in exterior siding. This technique is called 'rough-sawn.' Rough-sawn material is literally roughed up at the plywood mill before it is shipped to wholesalers. This process creates a surface that is coarser than original Eichler siding. Even though replacement siding rarely provides an ideal texture match, Breckenridge tends to be less rough than its Douglas fir counterpart.
Another reason that the rough-sawn texture is employed today is because it creates what is called 'tooth.' Tooth is the absorbency factor that allows paint to penetrate deeper into the wood. This is a good thing, because greater paint penetration means better protection from the elements. Some Eichler owners request that the rough-sawn texture be sanded down. Indeed, with care, this can be done. However, one must be careful, because sanding away too much material creates a thinner top surface layer. This thinning can cause the plywood to be susceptible to premature splitting and delaminating.
The one exception to the rough-sawn products described above is a material called Medium Density Overlay, or MDO for short. MDO is a high-quality exterior material that weathers very well. It also has a unique resin-impregnated material applied to the exposed surface. To the untrained eye, this layer simply looks like paper, but due to resin that is assimilated into it, MDO is far superior to standard plywood. The drawback to MDO is that it is extremely smooth and exposes no wood grain. Nevertheless, many homeowners have found that when painting, applying primer and paint with a napped roller brings about textured results that suitably match the original siding.
All plywood siding must have what is called a 'shiplap' edge at the vertical joints. This allows the siding to overlap and provide a water resistant joint. Using plywood that does not have shiplap edging is not recommended; without it, water eventually will penetrate the seams and provide a thriving home for rot. Siding must be installed within local building code specifications. Check with your local building department to ensure you meet the code for nailing, spacing, etc. And beware of short cuts.
Some homeowners think they are taking a successful short cut by applying new siding over a preexisting layer. In actuality, this method can result is serious warping and buckling. The same kind of buckling can occur when installing the siding too tightly against other panels; appropriate spacing is required to allow for expansion and contraction.
Painting or staining Eichler siding often presents its own set of concerns. Staining brings out the patterns of the wood grain but offers less protection than paint. Staining the siding requires that the wood grain matches the preexisting siding so as not to appear incompatible. Consequently, when staining, one should consider texture issues and the occasional patches that appear on most plywood from today's mills.
Paint, on the other hand, provides better protection than stain, but when applied it covers up the siding's inherent grain pattern. A quality paint application affords the most protection against the elements and also hides minor siding imperfections well. When painting, the siding must be clean and dry and free from dust and grease. For best painting and staining results, always refer to the application recommendations the painting manufacturer provides. Purchasing the highest quality materials, whether stain or paint, and using proper application techniques, will result in dramatically greater protection of your investment for many years. Regardless of the type of new siding product you choose, make sure to prime both faces of each sheet and all edges before painting. This is an all-important preparation step.
Your exterior siding is the first level of defense against the elements. When installed and maintained well, it will provide lasting protection and beauty to your Eichler home. So, when repairing or replacing your Eichler's siding, be patient—and seek out sound advice. You will not regret it.
Guest 'House Doc' Jeff Nichols and his partner and wife Annette have become a vital part of the Eichler community over the past 16 years with their Eichler Siding business (415-883-5300), manufacturing their own line of exterior siding.