The practical impact of this comes when you make joints. In a cabinet door, for example, you want the best appearance possible on the outside. On the inside, you still want it to look good, but small areas of burl, mineral streaks or sap wood won’t be the distractions they would be on a surface that is always exposed. Preparing the Exterior Plywood This guide focused on learning about the different types of plywood, and how to best stain them. You can write down all the other grade and core construction and face details but as you suggested these have different naming conventions from dealer to dealer and point of origin. The joints were then knocked apart to see if the nails pulled away with the face pieces, or remained in the end of the core being nailed. Particleboard core or MDF (medium density fiberboard) core are the other common types of plywood cores in use. Can I remember the name of the imported stuff that I bought last time? This means that the plywood is on the outside of the home such as a deck. T1-11 is an exterior-grade plywood designed for use as siding. Pull a sheet off the stack and sight down a long edge. Subscribe ». One of the big drawbacks to veneer-core plywood often won’t appear until finishing. Outdoor house sidings, children's treehouses, and raised garden bed sides are just some of the uses for the laminated wood sheets. The grain should look like several pieces of solid wood, 6″ to 8″ wide. Rotary-cut veneer will look like plywood, rather than solid wood. “Shop Grade,” “Cabinet Grade,” “Stain Grade,” and “Utility Grade” are commonly used terms that aren’t defined by any industry-wide standards. Exterior plywood is where the wood is bound together using water-resistant glues. If you are sanding a very large area, such as a room with plywood flooring, then you may need to use a commercial sander. However, painting can be used in most situations involving plywood as it is relatively inexpensive, versatile, effective, and long-lasting. However, this does not impact our recommendations. You can probably get away with using rotary-cut veneer for something such as the interior of a cabinet, but it won’t look right on an exposed surface next to solid wood. If you have a large area to sand, you should use an electric sander. CDX plywood, a stock item at most lumberyards, is a utility grade suitable for most outdoor projects. Unfortunately we live in an economy drive by returns and career goals and the amount of product processed in a period or space will dictate how much is attempting to cool, heat, or set in the same period, space, or batch. Radiant barrier plywood is most often used for roofing. In 3⁄4″-thick material, the thickness of the core layers can range from about 1/8″ on seven-ply material (five core layers plus the two face veneers) to less than 1/16″ in 13-ply material. Show. 14. Two were from the piece of Baltic birch plywood. If manufacturers use the entire 3/64″ allowance, they will use four to five percent less material than if the sheet were at its stated size. Exterior plywood carries an X stamp, which identifies it as suitable for use outdoors. Depending on the quality consciousness of the manufacturer, these cores can vary tremendously. If the sheet is badly warped or twisted, there is likely a problem in the core layers and conditions won’t improve as the sheet is cut up. Baltic, Russian and other European birch plywood faces are graded by the letters B (best), BB, CP and C (worst) for both the face and the back. A DIYer by nature, Deziel regularly shares tips and tricks for a better home and garden at Hunker.com. But when I go to buy it, the storm clouds come rolling in. Its layers are glued together with waterproof adhesive that prevents them from delaminating in wet weather. A seller who can’t explain what they have to sell might best be avoided. Exterior Plywood is intended for use in non structural, exterior applications where a high quality aesthetic finish is required. However, European buyers prefer WBP(exterior) plywood for indoor use . How much thinner than 3/4″ will it be this time? Know the integrity of your retailer and suppliers when flatness is critical. PC Prime Coat Masonite 03mmx2440x1220 . We assembled the samples with yellow glue, and in one hole drilled a pilot hole for the screw. The many types of plywood can differ in materials, number of layers, rating and grade. Exterior grade plywood can be used indoor , too . Basic pressed wood markings will have three letters showing the plywood’s application. Will the veneer be so thin that I sand through it with the first pass of the sander? We also included a piece of red oak plywood with a Luan core that had been stored in my garage for 10 years. Our samples of red oak from Lowe’s were nearly as consistent in thickness, with an average variation of .003″ in each small sample and a variation of .008″ within the sample group. In professional cabinetmaking, they are the preferred materials for quality work because they’re flat and of a consistent thickness. It comes in 3/4-, 5/8- and 1/2-inch thicknesses. 3. In the samples with hardwood cores – poplar, birch and the imported wood – the rabbets were smooth. The thinnest veneers are very easy to sand through and often will telegraph any unevenness of the core layers to the finished surface. If you can work around the structural issues, and overcome your prejudice, you can achieve much better finishes, and easier joinery if you use MDF or particleboard cores. Despite its reputation for flatness, plywood sheets will usually have some degree of bow, but this should be minimal. With softwood, plywood is plywood and particleboard is particleboard. What core? Several samples not only split the layer containing the screw, but pushed apart the glue joint between layers. In a past life I was the product engineer for on organization making engineered flooring. With hardwood plywood, any material can be between the face and back veneers and still be called plywood. Exterior construction-grade plywood usually displays a CDX stamp. There is a different standard for backs: 1 is the best and 4 is the worst. 3/8 Cat Ps1-09 Square Structural Douglas Fir Sheathing, Application as 4 x 8. Plywood is a frequently used material for external structural sheathing. The samples with the highest number of core layers were most resistant to splitting. Lastly, don’t be afraid to ask your supplier what they mean by the terms and grades they use. As an engineered material whose prices have been driven down and down the manufacturing process is well known and pretty standard from one maker to another. While perhaps not as harsh an environment as on a boat, depending on where the structure is situated exterior plywood can take quite a beating. Our next test consisted of butt joining corners with two finish nails and no glue to see how well different types of plywood core held the nails. We began with a 24″ x 24″ square of each type and cut that into 18 pieces that were 3-7/8″ x 7-7/8″. Expect to pay $75 or more for a 4′ x 8′ sheet of A2 plywood with plain-sliced veneer. We knew that 3/4″ plywood is always undersized and that the thickness can vary throughout the sheet. Plywood for Exterior use is also available but may be less cost effective as both the resins and the wood veneers within the product must be durable in the long term. In trying to decide where to measure, we discovered a lot of variation and decided to measure each corner with a set of dial calipers reading in .001″ increments. This creates a much more stable and structurally sound sheath that can be used over the exterior. It's constructed with waterproof glue and performs best when only semi-exposed to the elements, as it is when covered with siding or roofing. What do I ask for? Plywood is cut into almost any shape and absorbs paint quickly, making it … Only 10 pieces, however, were under .003″ variation within those samples. Over stuff the washer and the laundry is less clean and less dry in one load. He has degrees in science and humanities and years of teaching experience. First we checked the thickness. The second consideration is the overall flatness of the sheet. Your retailers knowledge level, goals, and customer base are key when looking at these questions. This guide will explain the different uses of plywood, as well as popular plywood sheet sizes and its rating and grade system, so that you can choose the best plywood for your project. Only six of 18 pieces showed .003″ or less variation within the samples. This lumber is widely produced and harvested in the Northwest, making it the favorite for affordability and availability. The first of these is the face veneer, if it is to be exposed. Plywood is a popular choice for residential and light-duty construction and is made from thin sheets of veneer that have been peeled from debarked wood. You can delay this process -- perhaps for many years -- by painting both sides and all the edges with high-quality exterior enamel. Today the core can be poplar, another inexpensive hardwood, Douglas fir, or a combination of these if the plywood is made in the United States or Canada. For bathrooms and kitchens, exterior plywood is better designed to resist water damage. 00 Expect to pay a premium for plain-sliced, bookmatched veneer. Many woodworkers object on principle to using anything but veneer-core plywood. It will last even if you leave it unfinished. The grade should be stamped on the side of the sheet but it is often missing in imported plywoods. On the shed walls use exterior rated 1/2 inch plywood for a waterproof finished look, and 3/4 inch CDX plywood on the roof for strength. What surprised us is how much variation there is, even in a small sample. You can use X-grade plywood for most outdoor applications, and when budget is a constraint, use CDX. A bonded exterior plywood must be used for applications involving long term full exposure. Exterior plywood means "plywood for outdoor use" . Going to a lumberyard is like going to a foreign country. Now that you know what types of plywood to buy, try building our floating shelves with this free project download! View as Grid List. Look at the given solid hardwood flooring done with plywood planks, beautiful packed, spaced and glued together. If you use interior plywood outdoors, it won't be long before the corners of the sheets separate, and eventually the plywood will become spongy and disintegrate. This type of plywood is too expensive for most other uses, but is the only choice when the application calls for it to be underwater. Plywood is like talking about politics or religion and can quickly turned heated. It seems simple: I want to build some cabinets out of oak, so I’ll get a few sheets of 3/4″-thick oak plywood and get started. Exterior plywood came on the scene in 1934 with the development of a waterproof adhesive. The type of plywood you choose will depend on economics, how much exposure to the elements the wood will get, and whether looks are important to you. This is bookmatched, plain-sliced veneer. Treatment chemicals include chromated copper arsenate (CCA), ammoniacal copper quat (ACQ), copper azole (CA) and -- safest of all -- borates. Decorative structures -- T1-11 is the best choice for siding, and it's also the best material for building sheds and outdoor storage boxes. This variety of plywood is designed to be very durable in the face of both physical wear and rain damage. Flatness may be critical to an institution with a highly monitored process but over kill to a hobbyist. Once dried, apply a water sealer to the plywood’s surface using a pump-up garden sprayer. The best exterior paint, be it latex- or oil-based, forms a durable bond on trim, siding, or decks—offering protection and a fresh look. Look at the joints between the layers. None of the samples split, and the differences seem to be in the grain structure of the core. The only two samples with a larger average variation, .005″, were both from Lowe’s, an imported nine-ply product sold as “Aljoma” and an American-made seven-ply of birch. Exactly how do you get a nice-fitting dado joint in an inconsistent, undersized panel? Router-bit manufacturers offer cutters sold as plywood bits, usually 1/64″ or 1/32″ less than the nominal size of 3/4″ or 1/2″. It often has visible knots and blemishes, and most of it is made from readily available Douglas fir or southern pine -- not expensive hardwood. Once again, nearly all grades are available, with A-C, B-C, and CDX the most common. If the plywood is put together using wat… Plywood is a composite wood that is composed of several layers of veneersthin sheets of wood that were sawed off the trees. The results indicate the quality of the core material itself and the quality of the glue bond between the core layers. Let the plywood dry for 24 hours. We went shopping for plywood in our area, and picked 10 samples from three sources – Lowe’s, Home Depot and our local hardwood supplier, Paxton Lumber. We thought we understood plywood until we put 11 different samples through a variety of tests. Robert W. Lang is a former executive editor of Popular Woodworking Magazine. When plywood is made, the alternating layers of core veneers are glued together with heat and pressure. Good veneer can easily double the price of a sheet of plywood. Every other piece should be a mirror image of the next one. MDF and particleboard cores, in spite of being weaker structurally, are flatter and more consistent. Plywood also comes with increased stability. Read these tips before attempting to paint exterior plywood for the best results. It happens. Page. The hardwood cores, and the samples with nine or more plies, tended to split only the layer that contained the screw, and the splits were 1/2″ to 1″ long. Poorly manufactured plywood also has a tendency to split or delaminate, especially when nails or screws are driven into the edges. Total immersion -- When building a cistern or other outdoor vessel to hold water, use marine-grade plywood. Grades B and lower for faces, and 3 and lower for backs, are generally considered only suitable for paint-grade work. Waterproofing plywood is relatively straightforward. Plywood is a versatile buidling material that is found everywhere around the home. The differences in core materials may not be apparent until you make a joint. The best choice depends primarily on the intended use, but budget can also be a consideration. Plywood is a necessity in many DIY and construction projects, but not every type of plywood works for every project. Hence, it can be the best alternative to hardwood flooring too. The easiest way to do this is to cut the groove to a smaller dimension and then mill a shallow rabbet on the board’s mate to match the width of the groove. There are a few plywood grading systems out there, but most of them follow an A-D classification with A being the best. Exterior Plywood V/s Interior Plywood Glue- The glue used is an important differentiating factor between exterior plywood and interior plywood. If your plywood is small, hand sanding will usually work fine. This block was glued from 10 of the 11 samples we measured for thickness. He worked as an expert consultant with eHow Now and Pro Referral -- a Home Depot site. These names may also change from time to time. https://www.popularwoodworking.com/wp-content/uploads/popwood_logos-01.png, https://www.popularwoodworking.com/wp-content/uploads/2019/05/june19_machinists_tool_chest10.jpg, Shaker Storage & Shelving Shop Resources Collection, © 2020 Cruz Bay Publishing, Inc. All rights reserved, Tool News: Rockler Convertible Benchtop Router Table, Free Woodworking Downloads From Lee Valley, I Can Do That! If the veneer is thin, and the core uneven, this unevenness will telegraph through and appear in the face veneer. Exterior plywood is seldom pretty. If you’ve never done it before and you don’t know the language, you’ll experience culture shock right off the bat – and sticker shock as well! Do I want rotary cut or plain sliced? Manufacturers maintain that this compression is unpredictable. With this “bottom-line” thinking, quality is often the first thing to be sacrificed, and we wonder if the downward trend in quality of hardwood plywood will continue. The total variation was .022″, with an average of .004″ among the small samples. For example a dining table kept in the kitchen or dining hall, or kitchen cabinet doors, is likely to be get wet. Because it's used for cabinetry and interior finishing, the appearance of interior plywood is more important than its resistance to moisture and rot. Relatively inexpensive, plywood is a favored budget siding choice. Apply several coats of the sealer, and re-apply after every two years. A1 or A2, with plain-sliced veneer, is usually the best grade available for work that will receive a clear finish. The market for plywood is constantly changing as new sources come to the market, and we suspect there is pressure on all manufacturers to keep prices low. Right behind it were the 10-year-old samples of oak with a Luan core. An avid craftsman and musician, Deziel began writing on home improvement topics in 2010. Items 1-12 of 25. The reasoning is that an undersized thinner panel will still fit in a groove cut at the nominal size, but an oversized panel would not. Primers help you not only resurface rougher textured surfaces like drywall, bare wood, plywood, and concrete without sanding, but they also lead to "improved filling and binding properties with the material underneath." The names the material is sold under are not the names of specific species. There are many specifications under plywood based on the chemical treatment of … By creating an account you agree to the Hunker. But one was .005″ thinner than the other. This free download is exclusive for our e-mail newsletter subscribers. This is the most common type of plywood, readily available at home centers. It is the most common bonding type of plywood available. For plywood furniture that will be kept indoors, the important point to consider is whether the wood is likely to get exposed to water. You simply need to choose the method that works best for your needs. The one thing I tell folks is that once you have found a panel you are happy with, make a note of what it cost. Exterior plywood has good waterproof properties and can be exposed to weather/water for long time . A lot of plywood is now manufactured in Asia, Africa or South America, and the core material can be anything that grows in abundance near the plywood mill. Any one of these can affect flatness. Sort By. It's less expensive than plywood and available virtually everywhere. The poplar core was most resistant to splitting among this group. Best Exterior Wood Paint UK. Note the variety of core materials and thicknesses. Some plywood from South America and Asia is graded on a similar system, but much of this material is not graded. What kind of plywood is best for roofing? The biggest problem is variation in thickness, but uneven or incorrect moisture content can also cause sheets that are warped, bowed or twisted. It also includes plans for a plywood tool storage cabinet. Different rules and grades are used for different types of plywood. When coated with a urethane finish, it will survive all but the harshest conditions. Manufacturers produce it by infusing regular plywood with chemicals under pressure to give it added resistance to mold and mildew. More plies are generally better, and hardwood cores are better than softwood. If one imported name gets a bad reputation, the same product may be sold under a new name, and people will try it, hoping that it will be better. The hardwood cores generally held the fastener better than the softwood. The total variation within the Baltic birch samples was .009″. Is it just me, or does plywood get a little worse every time I buy it? We made tests on our samples to see what the differences were between the “good stuff” and the “cheap stuff.”. If you are looking around to get best materials made from plywood then here is the list of top 10 most famous and best best Plywood … Each rigid glueline adds stiffness to the panel, and the thinner plies tend to be more consistent to begin with, and less likely to change after the panel is made. Use pressure treated 3/4 inch construction grade exterior plywood for the floor.