End-grain wood must always be well protected. End-grain wood absorbs even more moisture content than the horizontal parts of the wood. This is because the fibers and pores of the wood are open after sawing or milling the wood. Sealing the end-grain of the exterior wood with either glues, resinous pre-treatments or primers has been found to reduce water entry, though the effectiveness of such sealers varies widely.
PD CEN/TS 16969 specifies a test method to evaluate the ability of coating materials to seal the end grain of wood against ingress of water. The procedure mentioned in PD CEN/TS 16969 is relevant for joinery or wood based cladding materials whose service life can depend on the control of water penetration through the coated end-grain.
PD CEN/TS 16969 on grain sealing performance wood standard is useful for:
The biggest reason for sealing wood end grain is because the wood end grain is exposed on an end cut and it absorbs liquids up to 250 times more rapidly than other wood surfaces. By sealing and back priming all wood trim or decking you are giving the trim or decking a better chance to endure the elements by slowing water infiltration. Wood trim often rots due to improper installation methods, and from not priming or painting the end grain. Trim wood exposed to the elements soaks up water which start the rotting process.
The sections on sample preparation, wood, preparation of coated and uncoated samples, and wood conditioning have been discussed in thorough detail in PD CEN/TS 16969. Using PD CEN/TS 16969 guidelines you would be able to evaluate the ability of coating materials to seal the end grain of wood against ingress of water. PD CEN/TS 16969 guidelines enable you to provide your customers with suitable, reliable, and high-quality coatings.
CEN/TS 16969:2016