Georgia Pacific Georgia Pacific makes both types of structural panels including a plywood subfloor that has been treated to enhance moisture resistance. Ts75027 writes: Since I have a large stack of red oak, courtesy of a tornado a few years ago and a friend with a sawmill, it’s actually cheaper for me to build with solid wood; at least until my current supply runs out, that is. But I prefer to make cabinets out of plywood (except for face frames & door frames) because its simpler and faster than gluing up large panels from solid wood.
The use of panels depends on the selection of clones (because some of them have wood characteristics – for example, colour and density – which make them more suitable for home furnishing, structural uses or uses wherever higher mechanical requirements are needed), the production process (type of adhesive, bleaching, fireproofing) and the panel composition (layer structure, defectiveness of veneers).
A related problem is the act of covering wet plywood or similar panels with floor covering, deck coating, plaster or roofing, to entrap moisture and impose excessive stress against floor and wall covering and, worse, roofing, as plywood or particle board panels dry in place on floors, walls or roofs after having been covered with the final decorative and protective roofing, plaster, deck coating or floor covering.
Aviation-grade plywood is manufactured to a number of specifications including those outlined since 1931 in the Germanischer Lloyd Rules for Surveying and Testing of Plywood for Aircraft and MIL-P-607, the latter of which calls for shear testing after immersion in boiling water for three hours to verify the adhesive qualities between the plies and meets specifications.
Originally commercialized by the Trus Joist Corporation (now a Weyerhaeuser company) in the 1960s, engineered wood I-joists owe their beginning, at least in part, to a publication developed by the Douglas Fir Plywood Association, (the precursor to APA – The Engineered Wood Association) in 1959 entitled DFPA Specification BB-8, Design of Plywood Beams.
It is a matter of considerable importance that where appropriately specified plywood (in common with other wood based panels) is used in humid or exterior conditions, it is imperative that the product receives an appropriate protective finish, with particular attention being paid to the sealing of all faces and edges, to minimise moisture induced movement in service.
And sometimes those knots will fall out and leave a gap, so you can use light colored wood filler to plug and hide those – just like manufacturers do. Plywood was arguably the first engineered wood product, made by bonding thin sheets of wood together, with the grain of each sheet laid at opposing angles, known as cross-banding, which improves the strength and stability of the product.
The National Tile Contractors Association and the Resilient Floor Covering Institute both recommend plywood for subflooring and underlayment, because it doesn’t have the risk of swollen edges that OSB does. A ‘CE’ logo may be present as an indication that the OSB meets the requirements of the European Standard EN 13986. As for the appearance, there are several grades of Baltic birch available, but we most often carry the highest grade which is B/BB. JPFH writes: I agree with PDX Bob for me it is mainly a function of saving rare wood by use of veneer panels. Our craft plywood is manufactured according to the strictest quality requirements.
Frost, insect attack and severe chemical pollution may sometimes also have an adverse effect on the service life of plywood. Clare Cousins isn’t afraid to show off plywood in her Mornington Beach House project. In cabinetmaking, you refer to veneer core if you want material manufactured similar to construction plywood. Poorly manufactured plywood also has a tendency to split or delaminate, especially when nails or screws are driven into the edges. For example, in this photo there is probably plywood under the hardwood floor (probably a tongue and groove subfloor plywood), and most likely plywood under the exterior wall siding.
Unfortunately, much of the treated plywood found in retail lumber yards may not have been redried to the degree required for boat construction. When a roofless, partially built structure takes on water, both plywood and oriented strand board (OSB) used for floor decking can absorb water, swell, delaminate, and require sanding or replacement before finish flooring can be installed. In the late 1970s and early 80s, for example, the plywood principle gave rise to what today is a worldwide oriented strand board, or OSB, industry.
Because the core layers of Baltic birch are actually veneers of birch (rather than a softer, secondary wood) and form a void-free core, screws bite and hold with 100% of their threads. If you are planning to build cabinets or an interior project where the surface of the plywood will be seen, I recommend using a hardwood plywood, like a birch plywood that has a smooth A-grade face. It is difficult to assert whether or not the price of the birch ply compared favorably to that of solid wood, as rotary cut birch is not often used in lutherie.