Construction Basics
- 1. MATERIALS & FASTENERS Construction Basics
- 2. Materials
- 3. Lumber Stick Lumber – lengths of wood called so because they appear to be sticks. Made of solid wood Sheet Lumber – plywood in its various forms called so because it appears like a bed sheet. Made of panels of wood sometimes glued together.
- 4. Stick Lumber Stick lumber is referred to by it’s relative size of height by width. Standard 2x4, 1x3, 1x6 Rarely used in Theatre: 2x6, 2x8, 2x10, 4x4
- 5. Actual Measurements Stick lumber does not actually measure by it’s name. The thickness is reduced by 25%. The width is reduced by ½ an inch. Thus a standard 2x4 actually measures 1 ½ x 3 ½
- 6. 2 x 4 Actual Measurements 1 ½ inches 3 ½ inches
- 7. 1 x 3 Actual Measurements ¾ inch 2 ½ inches
- 8. Sheet Lumber Sheet lumber is referred to by it’s thickness and type and/or grade. All Sheet lumber comes in a standard 4ft by 8ft. The most common types of Sheet lumber used in Theatre are Plywood, Masonite, Luaun.
- 9. Sheet Lumber Types Luaun Masonite Plywood
- 10. Grades of Lumber: Stick #1 Common – tight knots, small pitch pockets, stains, season checks (best quality) #2 Common – Larger and more pronounced defects. (About as low quality as you can go and still build scenery) #3 Common – Low grade that can be used only if carefully selected by individual pieces. #4 and #5 Common – So low of grades of board, it is unsafe to use in scenery construction.
- 11. Grades of Lumber: Sheet “ B” Select – The best grade, a paint quality that only needs minor sanding. “ C” Select – There are more blemishes, price makes it ideal for theatre work. “ D” Select – Borderline grade. Common sheet goods tends to be rated by the side. i.e.: “BC” grade that is “B” on one side, and “C” on the other.
- 12. Wood Flaws Knots – if small and tight, will usually not affect the strength of a board, especially if they are contained within the edges. However, if the knot should traverse the width of the stock, will probably weaken the board to the breaking point. Remember that a knot interrupts the grain, and therefore weakens the board. Wane - occurs when the piece is milled leaving part of the outside of the tree. Sometimes bits of bark remain. Split – is an aptly named and obvious flaw, but some lumber yards don’t see it. The wood is literally split long-ways down the length of the wood.
- 13. Wood Knots
- 14. Wood Flaws cont. Cup – is when the width of the board is curved in one direction resembling a section of a tube being cut away long-ways. Crook – is when the board laid down flat on the wide side curves to the side. This can sometimes be fixed in the construction of a piece of scenery. Bow – this is when the wide side of the board curves lengthways. A light “bow” can usually be straightened and corrected in on-edge construction. Twist – this type of flaw is almost impossible to remove.
- 15. Wood Defects
- 16. Wood Storage Regardless of the size of lumber ordered, it must be stored evenly and with its own length and width to prevent warping. The most common method is to store it in horizontal racks with supports about every four feet. DO NOT MIX LENGTHS AND WIDTHS ON THE SAME SHELF, OR WARPING WILL OCCUR. Plywood will also warp if not stored properly. It can be placed in vertical racks which do not allow it to lean and bend, or it can be stored flat, if space allows. Often there is room to incorporate a plywood storage area under a large work table in the shop. “ Keepers” – any piece of lumber that is at least half sized (4 foot or longer) should be kept for future prop or scenery construction. Anything less than that size is hard to use and takes up too much space. “ New” - any piece of lumber that is in its original size (ie. 8 foot long or 4 foot by 8 foot sheets.)
- 17. Fasteners
- 18. Screws Screws are the typical fastener used in theatre. It does not wiggle loose like a nail can with extended use by actors. To prevent striping, you must A. use pressure, and B. keep the drive shaft aligned with the screw body. Do not overkill a piece of wood. Use the smallest screw possible to attach wood together firmly If you are putting a screw into 1x3’s, predrill the wood to prevent splitting.
- 19. Staples In Theatre we sometimes use staples. These can be either spring loaded or pneumatic. Pneumatic staples are typically used to hold wood together while glue dries into the joints.
- 20. Glue Glue is a highly effective fastener if used properly. The glue seeps into the fibers of the wood and joins them together creating a bond that is more durable than either screws or staples alone. This is used as the base bonding factor for how plywood, particle wood or fiber board is made.