DOCSLIB.ORG

Step 4. Roof-Bearing Assemblies

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Step 4. Roof-Bearing Assemblies Step 4. Roof-Bearing Assemblies ilclcngCI First, to have previously selected, from a wide variety of options, the combination of roof-bearing assembly (RBA) and tie-down system that is "right" for you and for your design. Second, to get the segments of your RBA safely up onto the wall (unless you have chosen to create the RBA in place, on top of the wall) and to make strong connections where they meet. Third, to "tie" this assembly to the foundation in such a way that the maximum expected wind velocity (a.k.a. the design wind load) cannot turn the RBA/roof into an ILFO (identified low-flying object). Walk-Through Jt extend continuously around the structure. Every wall carrying any roof load will need an • During the process of finalizing your RBA, but modern roof designs for square and design and creating plans, you will have rectangular buildings very seldom bear on selected the type of RBA to be used. Among more than two of the four walls (assuming a the factors that can influence this decision square or rectangular building). Even so, one are: might still choose to have the RBA be a —whether the RBA will act as a lintel over continuous collar, in order to tie the whole openings; [This would allow you to use less building together. A rigid, continuous RBA wood in creating the nonbearing door and could also serve as the lintel over all door and window frames, but may bring you to use window openings in the building, thus more wood in the RBA itself. It will enabling all the frames to be similar guarantee a straight, and probably level, roof (lightweight, non-loadbearing). It would also line, but may limit the number and size of distribute some of the roof load (otherwise openings, since the load is concentrated on carried entirely by the columns of bales the bale columns between openings.] between the openings in two of the walls) onto —the distance between the points on the the other two walls. RBA at which the trusses/rafters/vigas/ There are, however, advantages to having wooden I-beams concentrate the roof load, the RBA discontinuous (i.e., only on the two the magnitude of the load at each point and loadbearing walls). It saves labor and the whether it is the same for each point; cost of materials (both to the planet and the —the degree of compactness of the bales wallet). If the roof design is a gable, and if that the RBA will rest on; bales are going to be used to fill in the eaves —and, your various concerns about the (the triangular areas formed by the sloping materials required for the different options roof surfaces), builders often put in a light- (e.g., regional availability for purchase or weight horizontal stiffener at the level of the scavenging, cost [planetary and pecuniary], separate RBA's, before stacking bales to fill the tools and skills required to work with the triangles. If securely fastened at both ends them). to the RBA's, it can provide some of the You will have also decided whether it will collar-benefit of a continuous RBA. For more on stiffeners, see page 130. Page 65 Roof-Bearing Assemblies Roof-Bearing Assemblies Page 66 • Before you can fabricate your RBA, you and that the walls are properly aligned and must decide how to dimension it. It is typical secured under the RBA. If your system for to make the width slightly less than the keeping the top of the wall centered under the average width of the bales. This ensures that RBA involves putting holes in whatever is the RBA, which generally acts as the nailer acting as the waterproof cap, be sure to for the stucco netting, does not extend out carefully seal any openings through which beyond the edge of the bale wall at any point. water could get down into the bales. Choosing the length dimensions is more * Unless your RBA already adequately complicated. There are two obvious protects the top of the walls from invasion by approaches, each with potential advantages: rodents, deny them access by utilizing various 1) Use the foundation dimensions, taking materials (e.g., cement-based mortar, metal into consideration whatever setback you want lath, sheet metal, plywood scraps, old boards) to have from the edge of the bales. The alone or in combination. advantages to this approach are that you can * With your wall tops positioned, as finish building all the segments of the RBA appropriate, under the RBA and with the before the wall-raising is finished, that any chosen mechanism in place to keep them in pre-ordered trusses are guaranteed to fit, as this position, "tie " the RBA securely to the planned, on it; and that you will be mightily foundation. For our "model", we have chosen motivated to end up with dimensions at the an external tie-down system (e.g., polyester top of the wall that are real close to those at cord strapping with buckles or crimped the bottom. seals). "U"-shapedpieces of "tubing" (e.g., 2) Use the actual dimensions of the top of irrigation distribution line, salvaged hose), your finished walls as your starting point. positioned at a chosen interval in the The advantage to this approach is that you foundation, provide sleeves for the strapping. can customize both the width and length You will, hopefully, have taken steps to ensure dimensions to accommodate the actual shape that no concrete could get into the tubing and dimensions of your wall top (if this is when you were doing your pour. your first building, you will be lucky not to Straight pieces of plastic pipe, passing end up with walls that flare out a little). horizontally through a "collar" type Possible disadvantages are that you must foundation, have also been used for sleeves. leave some segments of the RBA unbuilt until However, even with bevels created at the the walls are finished, and that you may not openings where the strapping cord emerges, be able (depending on their design) to the right-angle bend may put unwanted, extra pre-order trusses. stress on the strapping at these points. * For the type of RBA on our "model" Regardless of the type of sleeve used, building, fabricate the roof bearing assembly however, care must also be taken to ensure on the ground in transportable sections. that sharp corners have been eliminated Then move these sections to the top of the where the strapping passes over the RBA. wall and connect them, taking care to get Small pieces of sheet metal, bent to make a strong connections between sections right angle, work well. Or, you can buy pre- (especially at corners). Make sure that the bent metal gizmos (e.g., Simpson A35s) at a diagonals are also as nearly equal as possible construction supply yard. Page 67 Roof-Bearing Assemblies Options for RBA's Least Rigid Bamboo Plank or TJI Beam 2 Sheets of Plywood or OSB * Could be used with loadbearing window frames and More Rigid angle iron to stiffen it over a non-loadbearing door frame. Double TJI and 2"X6" Mongolian 2"X6" Ladder (see next page) Two 2"X6"s 2"X6". 2"X4" w/ 2"X6" w/ w/2"X4" cleats continuous plywood plywood "web" Most Rigid "1 Concrete Bond Beam TJI with plywood 2"X6" w/ plywood (added weight will shorten (closed box) (closed box) permissible spans; see page 31) Note: 2" X 4" [5 X 10 cm] and 2" X 6" [5 X 15 cm] Roof-Bearing Assemblies Page 68 Some Examples of RBAs Truss Joist I-Beam (TJI) Box The pieces used for The top is typically "blocking" can be covered with plywood, pieces of TJI or or the equivalent, after dimension lumber. the space is stuffed with loose straw (some Sheetrock, under builders have treated waterproof drape, as the straw with a fire fire break (optional) retardant) TJIs can be ordered in lengths up to 60 feet [18m] to provide seamless rigidity. waterproof drape corner guard' strapping tie-down option Double-Layer Ladder-Type Mongolian Prototype (suggested by Dan Smith &' Associates) 2"X6" [5X 15.2 wooden or metal peg occassional ' cm] or wider fill or cover gap driven into bale through cross-brace with old boards hole in cleat board to exclude secure strapping rodents firmly to RBA strapping tie-down option 1/2" [1.3 cm] or wider 2" X 8" or 10" polyester [5 X 20-25 cm] strapping stuff space with tie-down option 2" X 4" or 6" straw (be mindful [5 X 10-15.2 cm] of rodent access) coil-strapping adjustable strong, overlapped corner connection, tie-down option side pieces set in to metal buckle ideal for handling hip rafters on as diagonal ensure adequate traditional, lightly-framed hip roofs corner bracing seat on bales Page 69 Roof-Bearing Assemblies Seismic Considerations Wooden Box Beam occasional blocking (cavity external cable bent rebar filled with straw) on outside, tie-down pins to hold attach roofing / 2"X6" system wall in place [5X15 cm] felt, expanded stuffed all-thread 2"X4" metal lath \0 cm] straw tie-down and/or stucco 2"X notch top system netting, here [5 X 15 cm] bales bolts TOP extra cross-brace, drilled, positioned, and end-nailed wherever threaded rods penetrate pressure-treated plywood (suggested by Bob Theis) 2"X4" [5X10 cm] provides attachment for notch Concrete Bond Beam stucco netting BOTTOM ^^ bottom sleeve placed here if using internal , .-•;> ^r bale tie-down rod or cable reinforced expansion strip concrete imbedded slab floor V .
Load more

Recommended publications
  • D12 – Collar Beam Roof
    D12 – Collar Beam Roof FRILO Software GmbH www.frilo.com [email protected] As of 21/04/2016 D12 D12 – Collar Beam Roof Note: This document describes the Eurocode-specific application. Documents containing old standards are available in our documentation archive at www.frilo.de >> Dokumentation >>Manuals>Archive. Contents Application options 4 Basis of calculation 5 Definition of the structural system 6 Definition via coordinates 6 Projection-related definition 8 Spanwise definition 9 Supports/purlins 10 Collar beam support 11 Cross section 12 Loads 13 Output 14 Output profile 14 Options - settings 16 Further information and descriptions are available in the relevant documentations: FDC – Basic Operating Instructions General instructions for the manipulation of the user interface FDC – Menu items General description of the typical menu items of Frilo software applications FDC – Output and printing Output and printing FDC - Import and export Interfaces to other applications (ASCII, RTF, DXF …) FCC Frilo.Control.Center - the easy-to-use administration module for projects and items FDD Frilo.Document.Designer - document management based on PDF Frilo.System.Next Installation, configuration, network, database FRILO Software GmbH Page 3 Collar Beam Roof Application options The D12 application allows the calculation of conventional collar beam roofs with sway/non-sway collar beams as well as rafter roofs. Available standards . EN 1995-1-1:2004/2008/2014 . DIN EN 1995-1-1:2010/2013 . ÖNORM EN 1995-1-1:2009/2010/2015 . BS EN 1995-1-1:2012 . UNI EN 1995-1/NTC still optionally available: . DIN 1052:2004/2008 In addition to typical roof loads such as uniformly distributed, weight, snow and wind loads, additional loads can be defined as uniform linear loads, concentrated or trapezoidal loads and assigned to groups of action.
    [Show full text]
  • Elements of Construction
    149 Chapter 8 Elements of construction INTRODUCTION mass of these loads can be calculated readily, the fact When designing a building, an architect plans for that the number or amount of components may vary spatial, environmental and visual requirements. Once considerably from time to time makes live loads more these requirements are satisfied, it is necessary to detail difficult to estimate than dead loads. Live loads also the fabric of the building. The choice of materials and include the forces resulting from natural phenomena, the manner in which they are put together to form such as wind, earthquakes and snow. building elements, such as the foundation, walls, floor Where wind velocities have been recorded, the and roof, depend largely upon their properties relative following equation can be used to determine the expected to environmental requirements and their strength. pressures on building walls: The process of building construction thus involves an understanding of: the nature and characteristics of q = 0.0127 V2k a number of materials; the methods to process them and form them into building units and components; where: structural principles; stability and behaviour under q = basic velocity pressure (Pa) load; building production operations; and building V = wind velocity (m/s) economics. k = (h/6.1)2/7 The limited number of materials available in the h = design height of building, in metres (eave height for rural areas of Africa has resulted in a limited number of low and medium roof pitches) structural forms and methods of construction. Different 6.1 = height at which wind velocities were often recorded socio-economic conditions and cultural beliefs are for Table 8.1.
    [Show full text]
  • Wood-Frame House Construction
    WOOD-FRAME HOUSE CONSTRUCTION U.S. DEPARTMENT OF AGRICULTURE «FOREST SERVICB»AGRICULTURE HANDBOOK NO. 73 WOOD-FRAME HOUSE CONSTRUCTION By L. O. ANDERSON, Engineer Forest Products Laboratory — Forest Service U. S. DEPARTMENT OF AGRICULTURE Agriculture Handbook No. 73 • Revised July 1970 Slightly revised April 1975 For sale by the Superintendent of Documents, U.S. Government Printing Office, Washincfton, D.C. 20402 Price: $2.60 ACKNOWLEDGMENT Acknowledgment is made to the following members of the Forest Products Laboratory (FPL) for their contributions to this Handbook: John M. Black, for information on painting and finishing; Theodore C. Scheffer, for information on protection against termites and decay; and Herbert W. Eickner, for information on protection against fire. Acknowledgment is also made to Otto C. Heyer (retired) for his part as a co-author of the first edition and to other FPL staff members who have contributed valuable information for this revision. The wood industry has also contributed significantly to many sections of the publication. 11 CONTENTS Page Page Introduction 1 Chapter 6.—Wall Framing 31 Requirements 31 Chapter 1.—Location and Excavation 1 Platform Construction 31 Condition at Site 1 Balloon Construction 33 Placement of the House 3 Window and Door Framing 34 Height of Foundation Walls 3 End-wall Framing 36 Excavation 4 Interior Walls 38 Chapter 2.—Concrete and Masonry 5 Lath Nailers 39 Mixing and Pouring 5 Chapter 7.—Ceiling and Roof Framing 40 Footings 5 Ceiling Joists 40 Draintile 7 Flush Ceiling Framing 42
    [Show full text]
  • Full and Partial Structures of Historical Roof Trusses in Assessment of Volume of Timber Used for Construction
    ARCHITECTURE CIVIL ENGINEERING E NVIRONMENT The Silesian University of Technology No. 3/2018 doi : 10.21307/ACEE-2018-033 FULL AND PARTIAL STRUCTURES OF HISTORICAL ROOF TRUSSES IN ASSESSMENT OF VOLUME OF TIMBER USED FOR CONSTRUCTION Magdalena CHYLEWSKA-SZABAT * *PhD student; Faculty of Civil and Environmental Engineering and Architecture, University of Science and Technology, Al. prof. S. Kaliskiego 7, 85-796 Bydgoszcz, Poland E-mail address: [email protected] Received: 6.11.2017; Revised: 1.12.2017; Accepted: 23.08.2018 Abstract Rafter framing is the basic roof frame that, through the trusses, transfers the load from the roofing to the main supports of the building. The construction material of these structures is usually wood. The development of roof framing construc - tion for wider and wider covers has caused an increased demand for construction timber for their construction. This paper points to this economic aspect based on an example of a geometric pattern of a rafter framing based on repetitive con - struction of full and partial girders. For such an understanding of the use of simple trusses by carpentry masters who con - structed roof framings in past centuries, it is pointed out in Ryszard Ganowicz’s works titled “Historical roof trusses of Polish churches” with section by Piotr Rapp’s “Historical development of roof structures in Polish churches”. This work is intended to provide an initial estimate of the percentage of wood saved in this solution. This assessment will be made on the basis of the inventory documentation of the roof framing of the church of the Michael the Archangel Church in Wierzbnik.
    [Show full text]
  • The Hammer-Beam Roof: Tradition, Innovation and the Carpenter’S Art in Late Medieval England
    The Hammer-Beam Roof: Tradition, Innovation and the Carpenter’s Art in Late Medieval England Robert Beech A thesis submitted to the University of Birmingham for the degree of DOCTOR OF PHILOSOPHY Department of Art History, Film and Visual Studies College of Arts and Law University of Birmingham September 2014 University of Birmingham Research Archive e-theses repository This unpublished thesis/dissertation is copyright of the author and/or third parties. The intellectual property rights of the author or third parties in respect of this work are as defined by The Copyright Designs and Patents Act 1988 or as modified by any successor legislation. Any use made of information contained in this thesis/dissertation must be in accordance with that legislation and must be properly acknowledged. Further distribution or reproduction in any format is prohibited without the permission of the copyright holder. ABSTRACT This thesis is about late medieval carpenters, their techniques and their art, and about the structure that became the fusion of their technical virtuosity and artistic creativity: the hammer-beam roof. The structural nature and origin of the hammer-beam roof is discussed, and it is argued that, although invented in the late thirteenth century, during the fourteenth century the hammer-beam roof became a developmental dead-end. In the early fifteenth century the hammer-beam roof suddenly blossomed into hundreds of structures of great technical proficiency and aesthetic acumen. The thesis assesses the role of the hammer-beam roof of Westminster Hall as the catalyst to such renewed enthusiasm. This structure is analysed and discussed in detail.
    [Show full text]
  • “Palladiana” Truss Roofs: Constructive and Structural Charateristics
    PORTUGUESE “PALLADIANA” TRUSS ROOFS: CONSTRUCTIVE AND STRUCTURAL CHARATERISTICS João S. Martins1*, António S. Gago1 and Pedro Lopes2 1: Departamento de Engenharia Civil, Arquitectura e Georecursos Instituto Superior Técnico - Universidade de Lisboa Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal e-mail: [email protected], [email protected] web: https://fenix.tecnico.ulisboa.pt/investigacao/icist 2: Academia Militar - Portuguese Military Academy Rua Gomes Freire, 1169-203 Lisboa, Portugal e-mail: [email protected] web: www.academiamilitar.pt/ Keywords: Construction, History, Roofs, Palladianas, Wood structures Abstract Rafter roofs, either gabled or hipped, were the traditional way to cover buildings in Portugal until the second half of the sixteenth century. Foreign architects and engineers, who designed in the late sixteenth century some Portuguese large buildings, inspired local designers and new types of roof structures, allowing covering large spans, were adopted at the beginning of the seventeenth century. In what concerns roof structures, São Roque Church, in Lisbon, built in 1584, was one of the cases that greatly influenced the Portuguese civil engineering. The main nave of São Roque Church is 17 meters wide and the traditional roof structures were not able to overcome such span. For that, the Italian architect Fillipo Terzi based his design in a roofing structure widely used in Italy, the “Palladiana” truss roof, but until then, unknown in Portugal. This “innovation” had become known by the Portuguese architects, engineers and building masters and in eighteenth century it was used when large spans were required. From the survey carried out, apparently, only three roofs built with this type of trusses remain nowadays in the Lisbon area: the one already mentioned in São Roque Church, another one in the Cathedral of Santarém, built around 1700, and another structure in the Asilo de Inválidos Militares, in Runa, Torres Vedras, built on the early years of the nineteenth century.
    [Show full text]
  • TFG Glossary of Terms 2015
    Copyright © 2015 Timber Framers Guild TFG Glossary of Terms 2015 KEY TO CROSS-REFERENCE TERMS See also See a related, similar thing Cf. Compare a related, dissimilar thing Also Another name for the same thing (q.v.) Which see ABUTMENT. In joinery, the end of one timber touch- BASKET HITCH. Open sling configuration for lifting ing another. See also BUTT JOINT. timber. Cf. CHOKER HITCH. ADZE. Handled edge tool (various patterns) with its BAY. Crosswise volume (perpendicular to roof ridge) in a edge at a right angle to the handle, used to shape or dress building, bounded by two bents or crossframes. Cf. AISLE. timbers. BEAM. Any substantial horizontal framing member. AISLE. Lengthwise volume (parallel to the roof ridge) in BEARING. Area of contact in a joint through which a building divided into several such spaces, usually three. load is transferred. Cf. BAY. BED TIMBER. Short, stout timber used to distribute ANCHOR BEAM. In a Dutch barn, the major tie beam concentrated loads at bridge piers and abutments. joined to H-bent posts, generally by outside-wedged BEETLE. Large wooden mallet typically weighing 15 to through tenons. 30 lbs. Also COMMANDER, PERSUADER. ANGLE TIE. Horizontal corner brace at plate level, often BENDING. Deviation from straight resulting from the combined with a dragon beam (q.v.) under hip roofs. application of force. In a bent member, the concave sur- ANISOTROPIC. Material whose structural properties face is compressed, the convex surface is tensioned and the are not identical in every direction. neutral axis is unaffected. ARCH BRACE 1. Curved brace. 2. Brace rising from BENT.
    [Show full text]
  • Structural Analysis of the Roof Structure in the Reformed Church
    LUND UNIVERSITY ½ LUND INSTITUTE OF TECHNOLOGY Division of Structural Mechanics ½ Sweden 1998 ½ Report TVSM-5087 CODEN: LUTVDG / (TVSM-5087) / 1-82 / (1998) ½ ISSN 0281-6679 STRUCTURAL ANALYSIS OF THE ROOF STRUCTURE IN THE REFORMED CHURCH Masters thesis by PETRA DIKE and SARA MACDONALD MALMBERG Supervisors: Karl-Gunnar Olsson, Div. of Structural Mechanics, Lund, Sweden and Svend Jakobsen, Eduard Troelsgård rådg. ingeniorer, Denmark. Carried out at the Div. of Structural Mechanics, Lund, Sweden. 3UHIDFH 3UHIDFH This Master’s thesis is the result of our work at the Division of Structural Mechanics at Lund Institute of Technology. The work has been carried out during the summer and the autumn of 1998. We take this opportunity to thank our examiner Karl-Gunnar Olsson at the Division of Structural Mechanics and our supervisor Svend Jakobsen at Eduard Troelsgårds rådgivende ingeniører in Copenhagen, Denmark, for all their support and encouragement. We would also like to show our gratitude to all the staff at the division for their assistance. We especially thank Jonas Lindemann for the assistance with VRML, Erik Serrano and Mats Gustavsson for helping us with the computer programs, and thank you Bo Zadig for helping us with the figures. A thank is also sent to Varmings Tegnestue in Denmark for the opportunity to use their drawings of the church. Lund in November 1998 Petra Dike and Sara MacDonald Malmberg $EVWUDFW $EVWUDFW The purpose of this Master’s thesis is to find and illustrate the behaviour of the roof structure of the Reformed Church in Copenhagen, Denmark. Explanatory visualisation results in an enhancement of the understanding of the statical behaviour.
    [Show full text]
  • Structural Analysis of Wood Trusses of San Paolo Fuori Le Mura, Rome, Italy
    Structural Studies, Repairs and Maintenance of Heritage Architecture XVI 163 STRUCTURAL ANALYSIS OF WOOD TRUSSES OF SAN PAOLO FUORI LE MURA, ROME, ITALY ELWIN C. ROBISON Kent State University, USA ABSTRACT The Roman double trusses of San Paolo fuori le Mura (FLM) are the oldest long-span Roman trusses for which sufficient information exists to perform a structural analysis. Span, spacing, and scantlings of members were recorded previous to the loss of the trusses due to a catastrophic fire in 1823. Wood species type can be inferred from comments by Pliny the Elder regarding other long-span trusses in ancient Rome. While the quality of the wood cannot be determined, the analysis results can be bracketed using allowable stresses from different wood visual grading standards. Dead and live loads can be estimated using loadings developed for current engineering practice. Quantifying the levels of stresses in the trusses of San Paolo FLM indicates a relatively conservative design. Stresses in the rafters, or upper chords, were reduced by the insertion of a collar strut providing an intermediate support to the upper chords. Even if it is assumed that timbers matching visual grade DF/L No. 2 were used, the combined flexural and axial stresses in the upper chords are well within those permitted by modern design standards. Keywords: Roman double truss, Early Christian basilica, San Paolo fuori le Mura, wood truss design. 1 INTRODUCTION The Emperor Constantine’s shift to Christianity in the 4th century changed both the culture and architectural traditions of Rome. However, the architectural changes were not as radical as the cultural changes.
    [Show full text]
  • TIMBER FRAMING JOURNAL of the TIMBER FRAMERS GUILD Number 72, June 2004
    TIMBER FRAMING JOURNAL OF THE TIMBER FRAMERS GUILD Number 72, June 2004 Historic Kingpost Trusses TIMBER FRAMING JOURNAL OF THE TIMBER FRAMERS GUILD NUMBER 72 JUNE 2004 CONTENTS NOTES & COMMENT 2 Notes & Comment TTRAG PROCEEDINGS 2004 4 MEDIEVAL ROOF CARPENTRY: CHARPENTE LAMBRISSÉE 8 The Journal at 20 Lynn T. Courtenay S editor of this journal, I will happily come out from behind HISTORIC AMERICAN ROOF TRUSSES 16 my desk to acknowledge the 268 contributors listed in the III. KINGPOST TRUSSES Cumulative Index for issues 1-66 (and more since then), Jan Lewandoski A and to wave hello to the 2000 people (in round numbers), who take their journals out of the mailbox four times a year. I don’t know what happens to most of those journals. Some of them must be read: at long intervals, letters arrive here, to amplify or to cor- rect. At even longer intervals, people speak up to wonder why this On the cover, view of the cedar roof trusses at the monastery of or that cannot appear in the journal. And, once in a blue moon, a St. Catherine’s at Mt. Sinai, Egypt, built between 548 and 565 commendation arrives. to commemorate the supposed site of the miracle of the burning bush. Kingposts truss the rafters only; the 20-ft. tie beams carry no ceiling load. Kingpost article begins on page 16. Photo, copyright 1995, by Lynn T. Courtenay. Copyright © 2004 Timber Framers Guild, PO Box 60, Becket, MA 01223 www.tfguild.org 888-453-0879 Editorial Correspondence PO Box 275, Newbury, VT 05051 802-866-5684 [email protected] Editor Kenneth Rower Contributing Editors Guild Affairs Will Beemer, Joel McCarty History Jack A.
    [Show full text]
  • Timber Framing
    TIMBER FRAMING ABUTMENT. In joinery, the end of one timber touching anoth- BORING MACHINE. A hand-cranked device with gears that er. See also BUTT JOINT. drive an auger bit, used to bore large holes, as in roughing out a ADZE. A handled edge tool (various patterns) with its edge at a mortise. right angle to the handle, used to shape or dress timbers. BOW. Deviation from straight in the length of a timber. Also AISLE. Lengthwise space (parallel to the roof ridge) in a building SWEEP. See also CROOK and CROWN . divided into several such spaces, usually three. Cf. BAY. BOXED HEART TIMBER. Timber whose section includes the ANCHOR BEAM. Major tie beam joined to H-bent posts, gen- heart of the tree. Since checks will not cross the heart, such a tim- erally with shouldered, outside-wedged through-tenons. ber can never split completely. Cf. FOHC. ARCH BRACE. 1. Curved brace. 2. Brace rising from bridge abut- BOX FRAME. Construction in which roof trusses are carried by a ment to support lower chord of truss. self-supporting structure of posts, tie beams and wall plates. Cf. ARRIS. The edge along which two adjacent surfaces meet. CRUCK FRAME. ASHLAR PIECE. Short vertical strut near the foot of a rafter, join- BRACE. Any diagonal timber (permanent or temporary) that ing it to a sole piece at the top of a masonry wall. resists distortion of a frame. See also KNEE BRACE. AUGER. A handled edge tool for boring holes in wood. BRACKET. Block tenoned or pegged to one timber to support BACKING.
    [Show full text]
  • Roofs Introduction
    ROOFS INTRODUCTION It may be defined as the uppermost part of the building, provided as a structural covering, to protect the building from weather. Structurally, a roof is constructed in the same way as an upper floor, though the shape of its upper surface may be different. Roof consists of structural elements which support roof is roof covering. The roof coverings may be A.C. sheets, G.I. sheets, wooden shingles, tiles, slab itself. REQUIREMENTS OF A ROOF It should be durable against the adverse effects of various agencies such as wind, rain, sun etc. It should grant the desirable insulation against sound and heat. It should be structurally stable and sound, it should be capable of taking the loads likely to come over it. It should be well-drained. It should have efficient water-proofing arrangement. TYPES OF ROOF Pitched or Sloping Roofs Flat Roofs or terraced Roofs Curved Roof PITCHED ROOF A sloping roof is known as pitched roof. These are suitable in those areas where rainfall/ snowfall is very heavy. FORMS OF PITCHED ROOF LEAN-TO-ROOF:-It is the simplest form of a pitched roof and it is known as pent roof. In this type of roof, one wall is carried up sufficiently higher than the other to give necessary slope to the roof. FORMS OF PITCHED ROOF GABLE ROOF:- This is the common type of sloping roof which slopes in two direction. The two slopes meet at the ridge. FORMS OF PITCHED ROOF GAMBREL ROOF:- This roof like gable roof, slopes in two directions but there is break in each slope.
    [Show full text]