RECYCLABLE WASTE PRODUCTS, BUILDING BOARDS AND PAPERSAr. Rino D.A. Fernandez, uapClass Instructor
Building Boards – a group of sheets of building materials often faced with paper or vinyl, suitable for use as a finished surface such as walls and ceiling. These are boards are flat, relatively thin in section and have been made to standard sizes usually by 4 ft. x 8 ft. ( 1.20 x 2.40 meters ). These building boards are made of several materials and are often simply called “ plywood”.
Properties of Boards / Wood1. Strong across as well as along the panel , more plies means a near equal in strength in both directions.2. Shrinking and swelling can be neutralize because wood grains run in one direction in half while the other half is at right angles.3. Split in its plane is impossible, because of successive layers at right angles to each other, thus nails and screws can be driven close to the edge of the panels.
4. Plywood can bent more easily than ordinary wood of the same thickness.5. The curvature depends on thickness and is limited by strength of outer pile in tension and inner piles in compression.6. Plywood offers innumerable possibilities for decoration because of great variety in colors and textures.7. Decorative effects is also possible to the face ply by pressure, sandblasting or etching with wire brushes.
Types of Building Boards1. Plywood- a structural wood made of three or more layers of veneer joined by glue , bonded and laid with grain of each layer is at right angles to each adjacent layer. Sub - types are : a. marine – ½” – ¼”(waterproof for exterior facing) b. fancy ¼’ – 1” (panelings and cabinets) c. ordinary ¼ - ¾” d. form plywood e. pre – finished paneling 3/16’ – ¼” ( paper overlaid, printed series, book matched and ribbon grained )
2. Hardboard – made from processed wood chips or fibers subjected to high pressure steam in pressure vessels, released and exploded forming into filtered cellulose. Unwanted chips are separated and then mixed into homogenous mass and poured into continuous board then later compressed into sheets. They are uniform, hard, grainless, smooth and with overlaps. Used for interior panels and durable sidings.
Grades of Hardboard :a. Standard – light, bendable, light brown and not suitable for exteriors.b. Tempered Hardboard – brittle and stiff but resistant to water penetration , ideal for exterior.c. Low Density – not as strong and durable as 1 & 2 , for decorative boards and often used as blackboard.
3. Insulating Fiberboard made from fibrous material like wood & sugarcane formed into board using asbestos as binder. Woods fibers made from sheared 5/8” chips then pressured and softened into live steam.
Two Basic Grades Insulating Grade – for insulating decorative panels and ceiling tiles with V- notch plaster base. Sheathing Grade – surfaces and edges are coated with asphalt and or with fibers impregnated with asphalt during manufacture.
Cane Fiberboard – shredded cane and processed into fibers.Mineral Fiberboard – made form asbestos fibers mixed with cementing agent ideal for fireproofing and acoustical purposes.
4. Chipboard made from building board particles & a binder (phenolic resin/urea formaldehyde glue) often faced with veneer.
Lends itself to a range of stain and paint finishes for indoor use while its weather resistance make it valuable for outdoor installation. It can also be laminated for plywood as interior finishing. Used for sub - flooring, interior and exterior walls.Sub - types are : a. Plain – unsanded, sanded on one side and sanded on two sides. b. Patterned – one grooved surface either evenly or random.
5. Particle Board – made from hardboard from relatively small particles, graduated from coarse at the center of the board to fine at the surface to produce a smooth dense surface.
Both sides or one side of surface aresanded while edges are filled according toparticular uses.It may serve as a base applied with woodveneers, plastic laminates, printed woodgrains and chalkboard coating. Used forshelving, millwork and other furnituremanufacturing.
6. Gypsum Board a wall board having a gypsum core
Variations: A. Special paper face where wood patterns can be printed and can be nailed with colored nails B. Glue laminated to an interior surface to produce a wood grain effect. C. Vinyl sheet faced made to imitate a textile surface held by glue or aluminum or plastic moldings.
7. Strawboard hardboard made of compressed wheat straw, processed at 350 F - 400 F with tough Kraft paper
Grades Structural board – 2” thick used for non- bearing partitions, plaster base, insulator, exterior sheathing, roof decking, and inner form face for concrete basement wall. Insulation grade – 2” thick, intended primarily for roof deck insulation.
8. Asbestos Cement Board a dense, rigid, board containing high proportion of asbestos fibers bonded with Portland cement.
Resistant to fire, flame and weathering butlow resistance of heat flow.Used as building form in sheet form andcorrugated sheeting. All types must bedrilled for insertion of screws, bolts sandother fasteners.
9. Corkboard from outer bark of oak tree, its granules are mixed with synthetic resin, compressed and formed into sheet from 1” – 6” and baked under pressure into rigid boards. Used exclusively as thermal insulating material and for vibration control.
10. PaperboardEither:a. A paper pulp pressed into boards 3/16”, or ¼” thick, 4’ wide, and 6-8’ long. Usually one surface is primed for easier finishingb. A layer of stiff paper folded into corrugated form and faced on both sides with a thick paper backing, cemented to the core
11. Mineral fiberboard thick mats of mineral fibers (glass/rock wool) covered with a backing of stiff paper on one or both sides to form rigid boards, ranging in thickness from ½” to 1” The usual board size is 2’ x 4’ & are used for roof deck insulation & are cemented to the deck with asphalt adhesive.
12. Plastic foam boards polystyrene & polyurethane plastics are formed by a patented process to about 40x their original volume. The foamed material is molded into boards from ½ - 3” thick, 12” or 24” wide and from 12’ long
Used for perimeter insulation for concreteslabs, for wall and roof-deck insulation, andfor roof decks when properly supported.These plastic boards have high insulationvalue and relatively high compressivestrength, and are flexible enough to fit overcurved surface.