Week 5: Chapter 7- Walls

 Chapter 7

Walls 

In Chapter 7 we learned about interior wall finishes and when they are suitable, what the different types of walls are, how to design interior walls appropriate to their uses, and how to specify interior wall finishes in finish schedules and finish plans. This chapter on walls will discuss wall systems, how the wall assembly works as a unit, and the finish materials for walls.

Chapter Notes:

   

Framing Systems 

A wall may be framed in several different ways. The three main systems are stud walls, masonry or concrete bearing walls, and column and beam structural frame walls with infill. A new type of wall being used is the structural panel wall.

• Stud walls- Stud walls can be built from either wood or light-gauge steel. These come in industry­standard sizes, with the most common being 2 inches by 4 inches or 2 inches by 6 inches. The standard spacing for wall studs is 12 inches on center, 16 inches on center, or 24 inches on center. The stud wall starts with a two-by-four or four-by-six laid horizontally, to which the individual studs are nailed. A top plate is added after all the verticals are in place. Window and door openings are then framed as needed, with sills and headers spanning between studs that are doubled at the sides, sills, and headers. Partial studs known as cripples are used to space the remainder of the distance both above and below the opening. After stud walls are framed, they are sheathed to make them stable against wind loads. Sheathing can be either plywood or oriented-strand board (OSB). OSB is far less expensive than plywood. Both plywood and OSB contain adhesives and often formaldehyde which are toxic chemicals. A sustainable choice would avoid both of these in order to reduce volatile organic compounds (VOCs) in the indoor air.
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  Concrete and Masonry Bearing Walls- masonry and concrete bearing walls are monolithic and made from either concrete masonry units (CMUs), brick or stone bearing walls, or reinforced concrete. In some cases, the CMU walls will be faced with a veneer of brick held to the CMU with brick ties. The challenges with this type of wall system include placement of electrical wiring, boxes, and switching; penetrations for plumbing and HVAC; and attachment of interior finish materials and artwork.
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• Structural Frame Walls- The structural frame, column, and beam systems can be filled in a variety of ways including stud-wall infill, insulation-panel infill, and other materials. Structural insulation panels (SIPs) can be made from wood or steel framing and differing forms of insulation, with the most common type being rigid insulation.

Insulation

• There are several forms of insulation traditionally used within exterior walls and interior acoustical partitions. The three main types include batt insulation, cellulose insulation, and rigid board insulation. Rigid board insulation can consist of several types: EPS (Expanded Polystyrene), XPS, (Extruded Polystyrene), Polyisocyanurate, Phenolic, Vacuum Insulated Panels, and Mineral Wool. 
• Insulation prevents heat loss or gain through the building shell (walls, roof, and floor) thus reducing the amount of energy required. Performance is measured using three values:
  
  
• Lamda measures the conductivity of the material and its ability to conduct, conduct and radiate heat
• R-value is measured on a given material thickness and its resistance to heat loss or gain (higher R-value means better resistance to hear loss or gain)
• Thermal transmittance through an entire assembly (wall, roof, floor) is measured using U-value.

Vapor Retarders

• Condensation within the wall cavity occurs when there is a substantial difference in temperature between the inside and the outside. The vapor retarder is installed in the wall toward the warmer side; this can vary depending on the climate zone. In cold climates, the vapor retarder is installed toward the inside; in hot and humid climates, toward the outside. Moderate climates do not need a vapor retarder.

Interior Substrate Materials

• The final component of the sustainable wall assembly consists of the interior finish material. By far, gypsum wallboard (also called drywall or sheet rock) is the most commonly used interior wall substrate. Whereas some manufacturers offer recycled gypsum and recycled paper facing for their products, a more sustainable option is plaster-finished walls.
• Unfortunately, plaster work is time-intensive and few tradespeople today have this knowledge. According to the International Green Construction Code (2018), ceiling and wall systems deemed to comply with VOC emission limits include ceramic and concrete tile, natural stone, gypsum plaster, clay masonry, concrete masonry, concrete, and metal.
• Gypsum wallboard consists of gypsum sandwiched between two layers of heavy paper. Manufacturers produce several types of wallboard for various uses. Type X is fire-rated. There are also wallboards that are water-resistant, abuse-resistant, foil-backed (which provides a vapor barrier), and pre-finished. Sheets come in a 4-foot by 8-foot standard size and thicknesses of 1/2 inch and 5/8 inch.
• Plaster work is applied in a three-coat system. Lath (either wood strips or metal wire) provides the base for the first coat, referred to as the scratch coat. A brown coat (or leveling coat) covers the scratch coat and the three-layer system is completed by a finish coat. Several types of texturing options can be applied to the finish coat, ranging from smooth to heavily textured. Like concrete, plasterwork cures as the lime, gypsum, and water undergo a chemical reaction.
  

Wall Finish (Interior)

How the space will be used helps to determine the appropriate wall finish that a designer chooses. In addition to painted plaster or wallboard, several other wall finishes adorn interior spaces, including tile, wood panels, stone, brick, fabric, paper, carpet, wire mesh, metal slats, 3-Form/acrylic panels, and various types of glass.

Paint

• Paints and coatings are nearly always used in some form on the interior surfaces of a building. 
• Recent developments in paint and coating technology have raised the sustainability criteria well beyond a discussion of VOC (Volatile Organic Compound) content.
• The entire life cycle of the paint or coating includes considerations about its use, maintenance, cleaning, durability, acquisition and manufacture, disposal, and possible recycling.
• The right paint can provide aesthetic appeal but can also reduce noise, provide a higher R-Value for insulation and therefore save money on heating and air-conditioning bills.
• The hiding power or opacity of a paint describes its ability to provide good coverage of the underlying surface. This hiding power can be determined using either ASTM D 344 or ASTM 2805-11, and can be related to the per unit VOC content. Thus, hiding VOC is a more accurate measure of sustainability than VOC content alone.
• A VOC evaporates into the air and combines with nitrogen oxide and sunlight to create air pollution. It also produces a noticeable odor that is harmful to people. Several programs and guidelines address low- and no-VOC paints and coatings including LEED, Green Globes, the Living Building Challenge, and Greenguard.
• High-quality coatings will not lighten prematurely. ASTM G90 is a test used to determine a coating’s ability to resist color loss. The Master Painters’ Institute (MPI) has established seven categories of gloss level that are used to determine the glossiness of a painted surface. 
• A glossier surface is more reflective and therefore requires less electric lighting in the space. A rating of 100 marks a perfect mirror-like reflective surface, while a rating of 0 is the flattest, no-gloss surface finish. 

Tile

• In a wet location, tile must be installed over cement board to avoid water penetration into the framing materials and insulation of the wall. Wall tiles can be made from many different materials, including concrete, clay, glass, metal, porcelain, and stone. They come in several different shapes.

Wood 

• Traditionally, wood paneling was applied directly to the wall studs. With the advent of manufactured paneling--which is much thinner than traditional wood paneling-- these panels were more often applied over a gypsum wallboard substrate. Today, many forms of wood are used as a wall finish, including full wall panels, wainscots, and in conjunction with other materials. To meet the sustainability objectives of a project, the use of FSC-certified wood is recommended.

Brick/Stone

• Brick and stone can be used as an interior wall finish in one of two ways: as a continuation of the exterior wall, or as a decorative applied finish. 
• In historic construction, it was not uncommon for the masonry bearing wall to be exposed on the interior, especially in basements and service areas.
• Generally, in the more finished spaces, these surfaces would have been plastered or whitewashed. Today these would be furred out, as is commonly done with concrete block. Furring uses thin strips of wood or metal channels screwed into the masonry that provide a surface to which the drywall can be attached.

Wall Textiles

• For acoustical purposes, fabric, paper, or carpeting may be used on a wall surface. Several points must be considered prior to using such a material. The building code will determine the fire rating required for all surfaces within a given occupancy use. Also, the designer needs to be aware of the multitude of green ratings used within the textile and carpet industries. By far the most stringent of these is to meet the cradle-to- cradle protocol.

Green Walls

• With the focus on sustainability and wellness, several designers use green walls in their projects. A green wall is a wall that integrates plants. These can provide improved indoor air quality depending on the type of plants that are used. They can also pose challenges with regard to the need to water the plants and if any of the plantings die.
• Several manufacturers provide the substrate for green wall installations. A typical green wall includes a vertical structure to hold a planting medium as well as the actual plants and often includes a hydration and fertilization delivery systems.

Moldings and Trim Work

• Historically, moldings fell into one of several types: supporting, terminating, separating, or translating. The various shapes evolved from structural components into more decorative additions to buildings. 
• Moldings are a part of the classical language of architecture. Columns--as defined by the Greeks and later enhanced by the Romans--include several variations from the least decorative (the Tuscan) to the most ornate (the composite order)
• Historically, where two surfaces met, moldings were used to make a clean joint. Moldings are made of several molded surface profiles derived from historical structural formations, typically of wood or stone. Classical moldings are additive, while Gothic or medieval period moldings tended to be subtractive. Moldings with convex profiles are considered robust or sturdy, while convex moldings are weaker and create a more pronounced shadow.
• The crown molding is composed of a cyma recta with a smaller cyma reversa or cove molding. Bed moldings consist of either an ovolo molding with a cyma reversa or an ovolo combined with a cove molding. The primary purpose of a molding or combination of moldings was to cover a joint between two surfaces. Over time the ends of exposed beams and other structural elements and joint-covering cleats were replaced by abstracted moldings. For example, the triglyph in a Doric entablature references three beams side- by-side, while the metopes were the spaces in between the beams.
• Today, moldings have been simplified and are referred to as trim. At the floor level, a base molding covers the joint between the floor and the base of the wall. Crown molding obscures the joint between the top of the wall and the ceiling plane. Because the walls and ceiling materials are often the same, crown molding is not always needed, although it is still commonly used in traditional interiors. 
• As used today, trim work is used to cover the joints between perpendicular surfaces and changes in material. For example, base board or base trim is used to conceal the transition from floor to wall and floor finish to wall finish. This joint is not always perfect and is generally concealed by molding.
• The cornice or crown molding provides the same type of concealment for the wall- to-ceiling connection, although this is often not used in contemporary construction.
• A chair rail was originally developed to protect plaster walls from chair backs and is, therefore, located about one-third the way up the wall.
• Sustainable trim options include FSC-certified wood products, reclaimed lumber that can be milled into trim, and plaster-cast moldings.

Casework (Built-in Furniture)

• Oftentimes, a designer will provide built-in furniture pieces such as bookcases, cabinets, and other storage solutions. These built-in units are called casework.
• Designers should be aware of joinery types, wood, and other materials most often used for casework, as well as operational and decorative hardware options in order to design these items consistent with the design intent of the overall project.
• Woods are divided into hardwood and softwood. Lumber varieties from deciduous trees--hardwoods--include maple, cherry, oak, mahogany, pecan, and birch. Softwood varieties used in construction include pine, cedar, cypress, spruce, and fir. Other forms of wood and wood by-products commonly used in casework construction include plywood, particleboard, and hardboard. Plywood consists of multiple thin layers of wood that are laminated together into a standard thickness such as 1/4 inch or 1/2 inch. Particleboard is composed of flakes of wood and resin, while hardboard includes wood fibers that are bonded under heat and compression.
• Either solid wood or wood veneers combined with other materials are all options for custom casework. A veneer, or a thin layer of hardwood, can be applied over a different subsurface. Veneers allow for a wide range of decorative designs. How the wood is cut will impact the visual appearance of the casework. 
• The most commonly used green options for casework include: plyboo (a plywood made from bamboo), medium-density fiberboard (MDF) without formaldehyde or other off-gassing toxins, and FSC-certified wood products. Consideration should be given to obtaining materials within an immediate radius of the building site.
• Casework is commonly built from solid wood, plywood, or MDF. Until recently, the adhesives used in plywood and some fiberboards emitted volatile organic compounds (VOCs) into the air. 

Interior Design Considerations

Designers need to know how to design partitions for specific interior conditions. These conditions include walls to control noise and prevent sound transmission, and walls to maintain fire separation and prevent the rapid spread of fire between spaces. Since interior designers cannot do structural design, they must also know how to recognize a bearing wall (structural wall) in order to avoid impacting the buildings structure.

Acoustical Partitions

• To control noise and sound transmission from one space to the next, acoustical partitions should be used. The acoustical properties of walls and ceiling assemblies are outlines in the International Green Construction Code 2018, section 801.3.3.3.

Fire Walls

• Another wall type with which an interior designer must be familiar is the fire-rated partition, called a fire wall. Based on the use of the space, specific fire separations are required by the applicable building code. These might be one-hour, two-hour or even three-hour fire-rated partitions. The goal of fire separations such as fire walls and doors is fire containment which means confining the fire to a specific place for a duration of time that allows for evacuation of the building’s occupants.
  

Bearing Walls

• Interior designers cannot legally change the structure of a building in any way. If a designer believes that a partition is bearing loads, or has any doubts about how to tell, they must always consult an architect or structural engineer. Some general rules of thumb can apply:
• Never remove a column.
• In wood construction, generally speaking, the flooring runs perpendicular to the framing; however, when in doubt, consult an expert.

Curved Walls

• New designers are often quite fond of curved walls. Several points should be considered before creating curved walls for a design.
• Every material has a maximum curving radius. How tight the radius of a wall may be limited by the materials a designer plans to use. It is important to consider the underlying framing and finish material when deciding to use a curve. 
• Also, contractors can easily snap chalk lines to locate orthogonal walls. To construct a curved wall, the radius of the wall must be properly indicated on the design plans and clearly located within the context of the other walls. Think through how you would build this wall in a model. What information do you need to be successful? Chances are that if it is hard for you to build in a model, it is even harder to construct in reality. Anything out of the ordinary will generally cost more. Curved walls can be used to create interest and enrich a design; however, their use should be carefully considered first.

Doors and Windows

Interior walls include doors and, in some cases, interior windows. Both doors and windows become part of the fire-rated assembly of the wall and are rated according to their fire-resistant characteristics.

Doors: Materials

• Doors are most commonly made from wood or steel. Depending on their use and location, they may be either solid or hollow core. Solid doors can have mineral cores, particleboard cores, or wood cores. For acoustical separation as well as fire rating, solid-core doors are required
• Standard door sizes for ADA compliance are 3 feet wide, and 6 feet 8 inches high. They increase in width in increments of 2 inches. Interior doors are usually 1 3/8 inches thick, whereas exterior doors are 1 3/4 inches thick. Other heights are available depending on the individual manufacturer.

Doors: Configuration

• Doors consist of some standard parts including panels, stiles, and rails. These elements can be assembled in several different configurations to achieve a variety of appearances.

Doors: Operation

• Doors have several different types of operation, including sliding, pocket, swinging, bi-fold, and overhead.
• The way in which a door is hinged and operates dictates whether it is a right-hand or left-hand door. This information is used to indicate hardware needs in a door hardware schedule.

Windows: Materials

• Like doors, windows are generally made from wood or metal. Aluminum and steel are both used to make interior windows.

Windows: Operation

• There are several different operational configurations for windows. Different operational types allow for different percentages of ventilation. For example, a double- hung or single-hung window can only allow for 50 percent ventilation when fully open. This is also true of a sliding window. A casement window, on the other hand, when fully open allows 100 percent ventilation.

Parts of the Window

• Window terminology is both complex and often misused. While many of these components may not be a part of the interior window, it is still important to understand the terminology associated with window construction.

Energy Issues

• In a sustainable building, windows and doors are among the most important components of the building envelope. Most air leakage occurs around window and door openings, making them an integral part of a sustainable design solution. The quality of the window or door directly relates to its construction. A high-quality window or door will allow less air infiltration when installed properly. Further, double-pane and triple­pane glazing are now widely available and further reduce heat loss and gain through the windows of the building. Proper weather stripping will also reduce air leakage.

Electrochromic Glass

• Electrochromic glass is also known as dynamic glazing or smart glass. It is activated using electricity which determines the amount of tint the glass will have. The glass can be manually or automatically controlled. It can be used to reduce interior heat loads from sun glare up to 20-26 percent.

Wall Schedules, Finish Schedules, and Finish Plans

A variety of construction documents are used to indicate the types of partitions in a building and the finishes they contain.

Wall Schedule/Wall Types/Partition Types

• The wall schedule is used to describe the wall types used within a given project. All acoustical partitions, fire-rated partitions, and any other specialty wall types in addition to all standard interior and exterior wall types are included in the wall schedule. Partial sections for each of these variations are also generally included.

Finish Schedule

• A finish schedule uses a table format to communicate all information about the interior finishes and details of every room within a project. This includes floor finish, base molding, wall finishes, ceiling type and height, paint colors, and casework information.

Finish Plan

• A variation on this sometimes used by interior designers is the finish plan. In this method, a plan overlay is used and all of the finish information is included within each of the rooms on the actual plan.

Leed Cl Rating System, V.4.1

Blogging assignment:

The case study I looked into was called The Power of Privacy. In this study, they said that Hybrid work is taxing on our brains. we are having to make decisions we have never had to make before. They give us some questions people might ask such as, should I book a space for a meeting? Do I have work that requires individual focus time? If I am in meetings are there participants in the office, remote, or both? All of these questions relate to the people who are working in offices now. they asked employees from over 11 countries what is most important to them at work and number one was privacy. "The ability to access privacy and find places in the office that help us think and feel better are woven tightly together," say the researchers. This is the information they came up with:

3 privacy factors- whether consciously or subconsciously these three factors influence people when they seek out privacy. 

• What is around me? "people evaluate the types of spaces available. how much privacy their personal workspace provided. How many people are nearby and what does company culture suggest about taking meetings in an open space."
• What am I doing? "Employees consider how much they need to focus on any given task. How confidential is the work? Can I be interrupted? How long is the meeting? What technology do I need? Is the conversation personal?"
• How do I Feel? "Preferences, self-awareness, and mood also influence people. some days people need a breather or to get 'off stage' when situated in a space where others can see and hear. Other people get energized being near colleagues."

They concluded that a range of privacy solutions that everyone can access can help productivity and keep employees happy. 

A Range of Privacy Solutions: