Preparation: Before finishing, repair all nail holes and surface irregularities. All surfaces should be clean and caulking should be in good condition. Seasoned southern cypress siding should be finished promptly at the time of installation to protect against moisture absorption, discoloration from rain, and mildew. However, under no circumstances should siding be finished when it is wet. Selection of Primer and Paint: Use a high-quality primer compatible with the paint being used–most paints will require an oil-based alkyd primer. High quality, oil-based paints, are recommended. Most water-based paints contain water-sensitive polymers and/or surfactants that might absorb moisture, causing the siding to swell or creating an environment suitable for biological degradation. These additives are present in a variety of paints, at different price levels, and their presence is not necessarily reflected on the label. The only safe approach is to use an oil-based exterior wood siding and trim. Light-colored finishes reflect heat more than dark colors and reduce the possibility of shrinking, checking, warping, and loosening of nails. Application of Paint: Always follow the primer and paint manufacturer’s recommendations. Priming all sides and edges of wood siding provides superior performance over all types of sheathing. After the prime coat has dried, apply two coats of paint to all exposed surfaces and edges. Brush application is recommended because it provides a more uniform coverage. The time of day, the temperature, dew, fog and rain influence tile quality of tile paint job. Follow paint manufacturer’s recommendations in regard to these factors. Application of Stain: Southern cypress siding takes stains very well, however, semi-transparent stains do not last as long as paint systems. Most semi-transparent stains will provide adequate protection for 18 to 24 months depending on weather conditions. Consequently, they require reapplication at regular intervals to protect the wood siding from warping, checking, shrinking, and loosening of nails. Where it is desired to leave wood in its natural state, it should be brushed on all sides and edges with a quality clear preservative, preferably with an anti-fungal additive (See Bora Care). Clear coating must be re-applied at frequent intervals. Nail Sizes for Wood Siding over Sheathing

Siding/Sheathing Combinations Recommended Nail Length Recommended Nail Length
(Use wood siding nails) Smooth Shank Ring Shank
3/4″ siding plus 1/2″sheathing 10d (3″) 8d (2 1/2″)
3/4″ siding plus 3/4″ sheathing 12d (3 1/4″) 9d (2 3/4″)
3/4″ siding plus 1″ sheathing 16d (3 1/2″) 10d (3″)


Nailing Methods