Cold Roof

Most building codes require a prescribed minimum amount of ventilation area at eave and ridge in a sloping roof commonly ' soo of the area of the ceiling. A building with a ceiling area of 3,000 square feet, for example, would require a total of at least 10 square feet of ventilation opening. Half this amount should be distributed along the ridge or high in the gable ends, and the other half should be distributed along the eaves. These high and low ventilation openings allow convection to work...

Function Accommodating Movement

Its movements, though seemingly small, are extremely powerful and can cause irreparable damage unless the building is detailed to accommodate them. There are a number of sources of movement in buildings that the detailer must keep in mind Temperature movement is caused by the expansion and contraction of building materials with rising and falling temperatures. Moisture movement occurs in porous materials such as wood, plaster, masonry, and concrete. These materials...

Function Providing Passages For Mechanical And Electrical Services

EVERY building is laced with a three-dimensional web of distribution lines for mechanical and electrical services ductwork, piping, and wiring for heating, cooling, ventilating, hot and cold water, sewage, fire suppression, electrical energy, illumination, telephones, temperature controls, computer networks, intercommunication systems, antennas, and alarm systems. Almost every existing building has been retrofitted with distribution lines for which it was not originally designed, making it a...

Detailing The Eave

We will begin our detailing of the building with the eave, because this one detail does the most to establish the appearance of the building and also seems to present the most problems. We adopt the customary scale of Yi 1', which allows us to show all but the most intricate of features. In developing this detail, we follow step by step the process that the carpenters will use to construct it, Rehearsing the Construction Sequence. We draw first the studs, top plate, and sheathing of the wall...

Expansion Joint in Brick Wall

Weakness in the surface, where cracking or crushing would tend to occur if no joints were provided. D> 4. Aluminum cladding components are subject to large amounts of expansion and contraction caused by daily and seasonal differences in air temperatures and by direct solar heating of the metal. Both horizontal and vertical expansion joints must be provided at appropriate intervals. Each joint must be designed to maintain the alignment of the components and to keep out weather while allowing...

Flexible rod anchor wind loads only

A brick veneer curtain wall stands on a concealed steel shelf angle that is supported by the frame of the building at each story. The veneer is too slender to support any load except its own weight. If an ordinary mortar joint were used below the shelf angle, a slight deflection or creep in the structural frame could cause the veneer to cam' the weight of the building instead of the frame. This would be disastrous The thin brick veneer would buckle and virtually explode off the building. To...

G

Minimum slope 2X maximum deflection + 1 100 Drain at Low Point of Sloping Roof Beams 8. Another special case of the wash is indicated on architectural drawings by the note pitch to drain. The rain gutter at the eave of a roof is usually pitched (sloped) to drain water toward the nearest downspout. Common slopes used for gutters are W or Va per foot (1 100 or 1 50). A steeper slope gives a greater capacity to handle water in a heavy rainstorm. 9. An industrial or basement floor slab is often...

Pride Of Craftsmanship

Painters can easily be persuaded to do masking, striping, and stenciling to create colorful patterns. Most heavy timber framers already apply chamfers, quirks, and lamb's tongues to their beams and columns. Proceed cautiously into these areas. Some of these traditional expressions of pride of craftsmanship can be exceedingly expensive if they are misused or overused, but it is often possible within even a modest construction budget to add a few small touches...

Info

Information Counter Design

The engineer agrees that this is acceptable. In the vertical direction, the backup have to fit between the top of the floor slab and the underside of the perimeter beam. The floor-to-floor height is 9'. The engineer would like the depth of the perimeter beam to be about 18 (measured downward from the top of the slab), but he says that he can be somewhat flexible on this, because he can change the width of the beam and add or subtract reinforcing if necessary to achieve the same...

Detailing The Windows

Selecting a Window Again taking a cue from nearby historic houses, we decide to use double-hung wood windows in our building. We plunge into the catalogs of several reputable manufacturers in order to choose the windows that we will use. We look for low maintenance and good appearance, and we decide to use a wood window that is clad with white vinyl on the exterior (Surfaces That Age Gracefully). We look for good thermal performance and find that all of the manufacturers whom we are considering...

Rehearsing The Construction Sequence

The act of designing and drawing a detail should be based on a mental process of rehearsing the sequence in which the detail will be assembled on the building site. 1. In the mind of a construction manager or a construction worker, a detail drawing should create a vivid, dynamic picture of actual materials, fasteners, tools, and operations. From the detail drawing, the builder should easily be able to visualize a sensible, workable process for assembling that part of the building. A good habit...

Cover plate 2 Building Separation Joint at Roof

Building Separation Joint

Leaking through the joint but adjusts readily to movement between the two sections of the building. A high curb on either side keeps the bellows from being submerged in water. The joint is filled with thermal insulation and a vapor retarder. The ceiling below is provided with a gasketed metal cover plate that can adjust to movement while retaining a reasonably attractive appearance. The bellows and the interior cover plate are common off-the-shelf components, typical of dozens of designs...

Aesthetics Introduction

Its details play a large role in this important function. Every truly great building has great details details that contribute to the aesthetic themes of the building, that harmonize with one another, and that create beauty out of the ordinary materials and necessities of construction. A building with a splendid thematic idea can fail as architecture if it has poor details details that are badly matched to its primary aesthetic, that do not relate strongly to...

Mwg

The perimeter of the building (Small Structures). The code permits a single 2X6 sill, but we prefer to double the 2X6 for greater stiffness and better nailing. We note that the lower sill piece should be made of preservative-treated wood to avoid decay from soil moisture rising by capillary action (Dry Wood). Nowr we drawr the framing and sheathing in order of construction The 2X12 joists and header, the W plywood subfloor, the 2X6 stud wall, and the Vi wall sheathing. We have dimensioned the...

Intensification And Ornamentation

Details can be embellished to add to the visual richness of a building. 1. Since the beginning of civilization, makers of things have evidenced love of their work by adding nonfunctional elements to their forms. Weavers have added textures, colors, and patterns. Tilemakers have added brightly decorated glazes. Carpenters have chamfered and carved their work. Shinglers have added scallops and sawtooth patterns. Masons have laid delightful patterns of headers, soldiers, rowlocks, and corbels in...

Reflective Surface And Airspace

A bright metal sheet or foil is an excellent reflector of radiant heat energy at any wavelength and can be used within a roof or wall assembly as an insulating material. To be effective, however, it must face a clear airspace that is at least Yi (13 mm) thick. 1. A bright aluminum foil in a wall or roof construction with a 1 (25 mm) airspace on one side has an insulating value of approximately R-2 in conventional units, which is R-14 in SI units. If the foil is bright on both faces and has...

J

Surface Mounted Reglet

Slope (wash) acts to prevent water from being forced into the vulnerable joint by gravity, and the overlap of the upper lip of the reglet over the flashing keeps water from reaching the joint between the two components. The reglet shown in this drawing is a traditional type that is largely obsolete it is molded into glazed terra-cotta tiles that arc built into a parapet wall by masons. Shims and or a sealant bead must be inserted into the reglet to hold the flashing or membrane in place. 6....

Dimensional Tolerance

See that it is considered normal for a concrete building frame to be out of plumb by as much as 1 cither way, and a steel frame may be even farther out of plumb. It is evident that we cannot design a cladding system to be attached tightly to the spandrel beams of a building. The cladding for a building with a concrete frame should be installed in a plane that lies at least 1 outside the face of the spandrel beams, and a more generous distance than this would be wise, considering that building...

Applying The Detail Patterns

THIS section of the book consists of three illustrated narratives. These describe the process of designing the key details of specific building projects in wood light framing, architectural concrete, and brick veneer on a midrise concrete frame. The intent is to show how one architect, the author, goes about designing the details of a building and to reveal something of his concerns, his mode of thought, and his way of working. Throughout these narratives, special emphasis is given to showing...

Architectural Detailings For Classroom

IT IS impossible to become good at detailing without repeated practice. Such practice is most effective when the resulting details are used to construct actual buildings, because then it is possible to experience the results of one's decisions and to see what has turned out well and what could be done better in the next building. However, this actual experience may not be fully available to students and interns, and one may wish to become more expert before attempting details that will actually...

Constructibility Forgiving Details

THE ability to create forgiving details is among the most rewarding skills of the detailer. A forgiving detail is one that always furnishes a way for a worker to deal easily with inaccuracies or mistakes. Most traditional details are very forgiving of inaccuracies and mistakes, because they evolved over a period of many years, gradually incorporating features that made them easier and more convenient for workers. When inventing new details, the designer should pay particular attention to...

Sealant Joints And Gaskets

Sealants and gaskets arc clastic materials that can be placed in a joint to block the passage of air and or water while allowing for relative movement between the two sides of the joint. A gasket is a strip of synthetic rubber that is compressed into the joint. Most sealants are mastic materials that are injected into the joint and then cure to a rubberlike state. A gasket seals against a surface by being compressed tightly against it. A sealant seals by adhering tightly to the surface. 1. The...

Building Separation Joint

Buildings that are large in horizontal extent should be divided into separate structural entities, each of which is compact enough so that it can react as a rigid unit to foundation settlement and other movements, thereby avoiding damage. 1. This drawing shows how building separation joints should be located at points of geometric weakness where cracking would otherwise be likely to occur. Notice how the joints divide the building into compact rectilinear volumes. At each joint plane, the...

Relieved Backs

Problems caused by cupping distortions in flat finish pieces of wood can be minimized by using a profile with a relieved back and by back priming each piece. 1. Cupping distortion of a wood board is caused by a difference in the amount of shrinkage experienced by the opposite sides of the board. The thinner the board is, the less the force that can be exerted on it by this difference in shrinkage. It is common practice to relieve the backs of flat pieces of wood mill-work by cutting one or more...

Checking Seasoning Distortions

To avoid seasoning distortions as much as possible, lumber can be cut from the log in such a way that the face of each board is approximately perpendicular to the annual rings in the wood. This is referred to as rift sawing or quartersawing, and lumber cut in this way is often called vertical-grain lumber. Vertical-grain lumber is best for flooring and for finish lumber that must remain flat baseboards, window and door casings, and tabletops, for example. Vertical-grain lumber also wears better...

Seasoning And Curing

Many porous construction materials should be seasoned or cured for a period of time following their manufacture, before they are incorporated into a building. This allows them to reach an equilibrium moisture content and to stabilize dimensionally before their movement is restrained by adjoining components of a building. 1. Wood is the building material that is by far the most subject to dimensional change from changes in moisture content. At the time it is cut, it is fully saturated with...

Cushioned Floor

The resistance to sound transmission of a floor asscmblv is measured in two ways. Resistance to the transmis-sion of airborne sound is expressed in decibels as a sound transmission class (STC), the same as for partitions. Resistance to the transmission of impact noise is expressed in decibels as the impact insulation class (IIC). Both of these quantities need to be controlled through detailing to achieve the desired acoustical performance. The accom panying table gives recommended minimum...

Vapor Ventilation

Small amounts of strqy water vapor escape through the cold-side air barrier . Most vapor ' is contained by warm-side vapor J retarder 2. Cold-Weather Vapor Movement in a Wood Light Frame Wall Water vapor must be given an easy escape route from the cold side of any vapor retarder. Try not to place vapor-impermeable materials on the cold side of insulation. This avoids trapping any small amounts of moisture that may get through the vapor retarder. It also allows stray moisture to be baked out of...

Utilizing Thermal Mass

When exposed to warm air or solar radiation, large masses of such dense materials as soil, masonry, concrete, and water absorb and store considerable quantities of heat. They do so over a period of time that depends on the thickness of the material and its thermal properties in a building, this period typically can be as much as 12 hours. In hot climates with large temperature differences between day and night, we can turn this delay to our advantage. We detail the building in such a way that...

White And Bright Surfaces

Bright metallic surfaces and bright white surfaces are very effective in reflecting the heat of the sun from the exterior of a building. 1. The accompanying table indicates the ability of various surfaces to reflect solar heat. A whitewashed or white-painted building will remain substantially cooler in summer than a dark-colored building. A roof covering that is bright white or bright metal will be very helpful in keeping the sun's heat out of a building, especially when compared with a black...

Drain And Weep

A strip of redwood held on with screws. This is not a rainscreen detail any defect in the glazing compound will result in water leakage between the glass and the rafter. Because of surface tension, water that has leaked through will cling to the rafter and run down its sides. This detail furnishes a small drainage gutter milled into the rafter on either side to catch this water and conduct it to the bottom of the rafter, where it is wept to the outdoors. cavity wall is expected to leak water,...

Detailing The Window Openings

Our basic spandrel section is now complete and becomes the base drawing from which we can prepare the other detail sections. On the first of these, we will work out the installation of windows. For this we rely heavily on the window manufacturer's suggested details, which are conveniently presented in its catalog at the same scale that we arc using 1 Vi 1'. We photocopy these catalog details so that we can slide them under our drawing paper and trace them. The window selection process began...

Detailing The Parapet

Masonry parapets should be avoided whenever possible. Because they are exposed to the weather on both sides they tend to leak, and they experience more thermal expansion and contraction than the walls below, which often leads to severe cracking between the parapet and the walls of the top story. On this project, however, we are required by local code to have a parapet. Working on a tracing paper overlay over the basic wall section, we make a horizontal mark 30 above the roof slab, the legally...

Overhang And Drip

Door Sill Overhang

Adhering drops or streams of water running down the wall of a building can be kept away from an opening in the wall by a twofold strategy (1) creating a projecting profile (an overhang) just above the opening and (2) creating a continuous groove or ridge in the underside of the projection (a drip) so that gravity will pull the adhering water free of the overhang. 1, 2. These are two versions of a door sill detail one executed entirely in wood and the other in a combination of wood and aluminum...

Condensate Drainage

In a building, provide channels and weep holes that allow gravity to remove the moisture without damage to the building. 1. Many proprietary designs for slope glazing systems and skylights are designed to catch and drain condensate that may run off the interior surface of the glass in cold weather. If this is not done, the condensate will drip into the room below. In this slope glazing purlin, condensate gutters are built into the lower flanges of the aluminum structural member. The gutter on...

Sound Waves Travel Through Ductwork

The control of sound transmission through floors is often critical, especially in apartments, hotels, and dormitories, where people live above one another. In addition to blocking airborne sound, floors must also impede impact and vibration noises from heels and machinery. The criteria of air-tightness, heaviness, and limpness that apply to partitions arc joined in designing floors by a fourth criterion, cushioning.

Designing The Rafter Ties

Bccause this structure has neither an attic nor a ridge beam, exposed horizontal ties must be installed at intervals to keep the bottoms of the raf ters from spreading. Some experimentation in plan and perspective leads us to decide tentatively on a spacing of 4' between ties. A simple mathematical analysis shows that, at this spacing, the tension in each tie will be 720 lb under a full snow load. This is a very small force A 1 X 3 could carry it safely. But there are reasons to use a larger...

L

Sound Transmission Classes of Various Framed Partitions The ideal soundproof partition is airtight, heavy, and limp. A thick, hanging sheet of soft lead that is sealed around the edges fulfills all these requirements. It is expensive and unattractive, however, so we detail partitions of a combination of standard materials in such a way that we incorporate the necessary qualities of airtightness, heaviness, and limpness. 1. The degree of resistance of a...

R38 Roof Construction Detail

If we decide to use plastic foam insulating materials, a further look at the manufacturers' catalogs reveals the following possibilities Extruded polystyrene R-5.6 per inch Isocyanurate foam R-7.2 per inch Phenolic foam R-8.3 per inch We also discover from ASHRAE Fundamentals that the R-valuc of a gypsum board ceiling and interior air film is only a bit over 1. The R-valucs of the ventilating airspace, sheathing, roofing, and exterior air film cannot be taken into account because the...

Detailing Sitecast Concrete

0American Concrete Institute Committee 303. Guide to Cast-ln-Place Architectural Concrete. (This is an excellent guide to detailing and specifying exposed concrete surfaces.) Address for ordering ACI, Box 19150, Detroit, MI 48219-0150. 0 American Concrete Institute 117, Standard Tolerances for Concrete Construction and Materials. (Dimensional tolerances for concrete work are spelled out in detail.) Address for ordering See above. 0Concrete Buildings New Formwork Perspectives. (This is a very...

Rake shingles

Roof Shingles Detailing

Edges and nail heads along the very top edge of the sidewall shingles, we make this nailing strip about an inch narrower than the trim shingles, thus allowing the trim shingles to overlap the sidewall shingles by a generous amount. We must specify a width for the rake trim shingles 3 is perhaps the minimum that will allow for proper nailing to the nailing strip beneath. We select the actual width by studying the appearance of rake trim courses of various widths on the end elevation of the...

Expansion Joints in Aluminum Vertical Mullions horizontal Movement

Control Joint Sidewalk

A control joint is an intentional line of weakness that is created in the surface of a brittle material that tends to shrink. Its role is to encourage any shrinkage cracking that would occur within itself, in order to avoid random cracking of the surface around it. 1. A sidewalk crack is a control joint that is formed by tooling a deep crack into the wet concrete. When the sidewalk shrinks, cracking is channeled to the tooled crack. The sidewalk remains as a group of large, stable rectangular...

General References On Detailing

Masterspec. Washington, D.C. Updated continually, this is an encyclopcdic reference on selecting and specifying materials and components for buildings. It is available in both printed form and on diskettes. Address for ordering The AIA Service Corporation, 1735 New York Avenue, N.W., Washington, D.C. 20006, 800 424-5080. 0 Allen, Edward. Fundamentals of Building Constmction Materials and Methods 2nd ed. . New York, John Wiley amp Sons, 1990. This is a solid, general...

Vertical Chase

A vertical chase is a concealed passage in which services can run from ground to roof and door to floor. A hollow wall that serves as a vertical chase can often perform some horizontal distribution functions as well. 1. The hollow vertical spaces between wood or steel studs in a wall or partition furnish convenient passages for small-diameter services, usually without further attention from the detailer. Vertical runs of electrical wiring or water supply piping lit easily into these spaces,...

Eliminating Openings In Building Assemblies

A shingled roof has an opening under each shingle. A wall has cracks around windows and doors, and joints between the units of material from which the wall is made. Additional cracks and holes may form as the building ages and deteriorates. We can attempt to eliminate all these openings by using preformed gaskets and sealants. As a sole strategy this is unreliable. Gaskets may not seal securely if they are the wrong size or resiliency, or if the surfaces they...

Rustication Strip Detail

Bad Architectural Detailing

Treated plywood Comer bead Casing bead Detailing the Window Openings After considerable trial and error on tracing paper overlays, the window head and sill arc added to the developing section. These details will have to be refined further after consultation with the window manufacturer. Working from the window catalog typical detail that shows rough jambs of wood, we are proposing tentatively that the head and jambs of the window unit be screwed to strips of plywood that are mounted to the...

Elevation Studies

We need to study at larger scale the relationships of the rustication strips, the terminations of the various pours, the window openings, and the control joints. For this purpose we construct a larger-scale elevation view7 showing the form tie holes, rustication strips, control joints, and sill wash. After some tracing paper studies of alternatives, we decide to terminate the wash with a sloping end plane. The pattern of the recessed strips and form tie holes strikes us as being neatly...