Estimating building costs part 2
➤ Gửi thông báo lỗi ⚠️ Báo cáo tài liệu vi phạmNội dung chi tiết: Estimating building costs part 2
Estimating building costs part 2
11Wood11.1INTRODUCTIONWood is one of the oldest and most used materials for construction work. Il is used extensively for temporary work, such as form Estimating building costs part 2 mwork and scaffolding, as well as for permanent work, such as floors, walls, and roof framing. The use of wood as the basic construction material has been due lo its availability, strength, durability. and workability. In addition, the aesthetic nature of wood also makes it a favorite finishing mate Estimating building costs part 2 rial used in most home and office projects.Applications of wood framing have been more prevalent for light construction such as houses and small buildEstimating building costs part 2
ings. This chapter discusses wood as used in these light construction projects. Because the framing methodology discussed in this chapter is more wide11Wood11.1INTRODUCTIONWood is one of the oldest and most used materials for construction work. Il is used extensively for temporary work, such as form Estimating building costs part 2 is division is primarily divided into two main categories: rough carpentry and finish carpentry. Rough carpentry deals with such structural components of construction like floor, wall, and roof framing. Finish carpentry', on the other hand, adds finishing touches to a project. Il deals with smaller Estimating building costs part 2 construction items such as the exterior molding, fascia, and interior trim. Finish carpentry also includes the installation of prefabricated woodworkEstimating building costs part 2
such as cabinets and stairs.11.2ROUGH CARPENTRYRough carpentry includes all the framing and sheathing in a project. In taking off for rough carpentry,11Wood11.1INTRODUCTIONWood is one of the oldest and most used materials for construction work. Il is used extensively for temporary work, such as form Estimating building costs part 2 tanding of how the construction will be executed in order to accurately lake off for quantities of lumber. For example, to determine the amount of concrete required for a concrete slab, the estimator need only determine the floor dimensions in order to calculate (he desired volume of concrete. Howev Estimating building costs part 2 er, for wood floor framing, the estimator needs to determine not only the floor dimensions. but also the types of sill, joist, header, and subfloor toEstimating building costs part 2
be used. In addition, the estimator needs to know how each of these components will be pul together, such as the spacing between the joists and where11Wood11.1INTRODUCTIONWood is one of the oldest and most used materials for construction work. Il is used extensively for temporary work, such as form Estimating building costs part 2 each piece of lumber needed for the work.11.2.1 LumberThe main material used in rough carpentry is lumber. Lumber or dimension lumber refers to a processed wood member that is less then 5 in. in the smallest dimension. A member that is 5 in. or larger in its smallest dimension is sold astimber. The Estimating building costs part 2 most common thickness for dimension lumber is 2 in., with 2 in. by 4 in. and 2 in. by 6 in. being the most commonly used sizes. Boards are usually 1 iEstimating building costs part 2
n. thick and come in various widths, typically ranging from 2 to 10 in.Lumber is available in many grades and is produced from many species of trees. 11Wood11.1INTRODUCTIONWood is one of the oldest and most used materials for construction work. Il is used extensively for temporary work, such as form Estimating building costs part 2 ming work. Oak. maple, redwood, and while pine are used more for flooring, siding, and finishing work. The grading of lumber varies by the species of tree, seasoning method, and (he degree of imperfections in (he wood.Lumber for general building purposes is called yard lumber and is usually produced Estimating building costs part 2 from pine and fir. Yard lumber can generally be categorized into two major groups: common lumber or select lumber. Common lumber has defects and blemEstimating building costs part 2
ishes and is not suitable for finishing purposes, bill is satisfactory for general construction purposes where appearance is not an issue. Common lumb11Wood11.1INTRODUCTIONWood is one of the oldest and most used materials for construction work. Il is used extensively for temporary work, such as form Estimating building costs part 2 strength is required. Grade 3 and 4 have many defects and lend themselves to uses where strength is nol critical. Select lumber has minimal defects and blemishes. This lumber is used where its surfaces will be exposed to view, such as for trim, facing, moldings, and other general finish carpentry. S Estimating building costs part 2 elect lumber is further classified into grades A. B, C, and I). Grades A and B are the best and are suitable for natural finish. Grades c and D have mEstimating building costs part 2
inor defects and blemishes that can be painted over.In addition to the specifications of the various lumber grades, lumber can also be further specifi11Wood11.1INTRODUCTIONWood is one of the oldest and most used materials for construction work. Il is used extensively for temporary work, such as form Estimating building costs part 2 preservative chemical to be applied under pressure, thus maximizing the chemical penetration and giving the wood maximum protection against decay and termite allack. Pressure-treated wood is required in these conditions:1Wood member in contact with masonry or concrete:2Wood member al grade or below Estimating building costs part 2 grade, or less (hen 8 in. above ground: and3In crawl space, floor joists less then 18 in. above interior grade and wood beams less then 12 in. above iEstimating building costs part 2
nterior grade.The availability of the various grades of lumber for a project's location must be investigated as part of the estimate. This is also imp11Wood11.1INTRODUCTIONWood is one of the oldest and most used materials for construction work. Il is used extensively for temporary work, such as form Estimating building costs part 2 ducts fluctuate widely from location to location and from season to season depending upon economic conditions. Therefore, it is advisable to call local suppliers for the latest market price.11.2.2Lumber Sizes and MeasurementsLumber is produced in many shapes and sizes. The size of lumber is given in Estimating building costs part 2 inches (thickness and width) and its length is always in feel. In specifying lumber, sizes are stated along with the wood type and the grade requiredEstimating building costs part 2
, such as Southern Yellow Pine No. 2 & Beller 2X4X10.Lumber is designated based on its nominal dimension size. Nominal dimension is the full size of r11Wood11.1INTRODUCTIONWood is one of the oldest and most used materials for construction work. Il is used extensively for temporary work, such as form Estimating building costs part 2 urfaces, thus giving it a uniform size and smooth surfaces. Lumber can be surfaced on one or more sides. Some of the abbreviations for surface finishing are S1S2E for “smooth surface, one side, two ends” and S4S for “smooth surface, four sides.*’ The dressing operation removes some lumber material i Estimating building costs part 2 n the process, resulting in a smaller dimension size for dressed lumber. The actual size of lumber is sometimes referred to as the dressed size. In adEstimating building costs part 2
dition to smoothing the surfaces, dressing can also prefabricate tongue-and-groove ends to planks or board, thus permitting belter lilting of the memb11Wood11.1INTRODUCTIONWood is one of the oldest and most used materials for construction work. Il is used extensively for temporary work, such as form Estimating building costs part 2 off process. Il is also important to state the number of dressed sides required and any other special requirements, such as predrilling, when ordering lumber.Lumber can be produced and sold in green or dry conditions. Green refers to lumber fabricated at a moisture content of more then 19%. Lumber f Estimating building costs part 2 abricated at a moisture content less than 19% is rated as dry. Green lumber must be dressed to a slightly larger dimension than dry lumber. This requiEstimating building costs part 2
rement ensures that the lumber achieves approximately the same actual dimensions after air drying in service. Table 11.1 shows the nominal dimensions 11Wood11.1INTRODUCTIONWood is one of the oldest and most used materials for construction work. Il is used extensively for temporary work, such as form Estimating building costs part 2 xample. 20 pieces of 2X4X 12. However, commercially lumber is bought and sold in volume, which is computed from its nominal dimensions. Therefore, lumber should be taken off and tallied by volume. The unit volume of lumber is “board feel measure” or just “board feel” (B.F.). Prices of lumber arc typ Estimating building costs part 2 ically quoted per 1000 board feet or M.B.F. A board foot is the equivalent volume of a piece of lumber 12 in. by 12 in. and 1 in. thick. Therefore. 1Estimating building costs part 2
board fool of lumber is equal to 144 in5. Board foot volume can be calculated by determining the size or cross-section of a member (in inches) and the11Wood11.1INTRODUCTIONWood is one of the oldest and most used materials for construction work. Il is used extensively for temporary work, such as form Estimating building costs part 2 idth (in.) X Length (ft) ... ..Number of R. F. =------i— -----^77—*— --------—(11.1)Table 11.1 Nominal and Dressed Sizes of LumberNominal size (in.)Dry S4S— actual size (in.)Green S4S— actual size (in.)2X41 1/2 X 3 1/21 9/16 X 3 9/162X61 1/2 X 5 1/21 9/16 X 5 5/82X81 1/2X7 1/41 9/16 X 7 1/22 X 1011/ Estimating building costs part 2 2x9 1/41 9/16 X 9 1/22 X 121 1/2 X II 1/41 9/16 XIII/2Example ILL Calculating the Board Feet LumberGọi ngay
Chat zalo
Facebook