Material types

This page includes definitions and descriptions of many commonly used construction materials. Several materials are typically used to create a layer-by-layer construction (e.g. wall construction or roof construction).

Air cavity

Air cavities in wall and roof construction serve several important purposes including:

• Thermal insulation
  • The air acts as an insulator, reducing heat transfer.
• Moisture control
  • Allows for evaporation to remove moisture
  • For exterior constructions, the cavity allows any moisture to drain away before reaching the inner surfaces
• Accommodating space for utilities such as piping, and electrical wiring.

Building board

Building boards provide a surface for attaching siding and other exterior finishes. They contribute to the building's rigidity and resistance to wind and other forces. They provide some (but not much) amount of insulation and moisture resistance. Some types of building boards include:

• Plywood - made from layers of wood
• Oriented Strand Board (OSB) - made from compressed wood strands
• Fiber cement board - made from cement and fibers and often used in areas with fire and moisture risk
• Drywall/gypsum board - primarily used as an interior wall finish

Building siding

Building siding is the exterior layer applied to the outside of a building (also called "exterior cladding"). It's purpose is to protect the building from the elements such as rain, wind, and sun. It is also a key component of the building's aesthetic appearance. Some types include:

• Wood
• Vinyl
• Metal
• Brick or stone veneer

Siding is attached directly to the building board.

Building membrane

Membranes serve as barriers against moisture and air and are important for the building's durability and energy efficiency. Types of membranes include:

• Air barrier - stops airflow through the building envelope
• Vapor barrier - controls the movement of water vapor to prevent condensation within the wall structure
• Waterproofing membrane - used in roofs, basements, and foundations to prevent liquid water from entering the building
• Vapor-permeable membrane - prevent liquid water from entering, but allow water vapor to escape the building

Concrete

Concrete is widely used for many applications due to its strength and durability. It is made of several components including cement, aggregates such as gravel and sand, and water. Some common applications include:

• Foundations
• Floor slabs
• Walls
• Structural elements

Concrete's high thermal mass allows it to absorb and release heat which can contribute to energy efficiency if designed appropriately. For example, during warm weather, unwanted heat gains can be absorbed by exposed concrete walls or floors, helping to prevent excessive heat gains in the building during the day and then releasing it gradually as temperatures drop in the evening.

Precast concrete sandwich panels

Precast concrete insulated sandwich wall panels, or sandwich wall panels, are composed of two concrete panels, or wythes, separated by a layer of insulation and connected by wythe connectors and the connectors can be designed to minimize thermal bridging. The concrete is usually reinforced for additional structural strenght.

These panels are manufactured off-site allowing for rapid installation on-site. They are most commonly used for exterior walls.

Curtain wall

A building with curtain wall design. (Source: Wikimedia Commons)

Curtain walls are extremely common in high-rise architectural design and other larger buildings. They are a non-structural exterior wall system that hangs from the building's structural frame. The name "curtain wall" comes from the fact that they hang from the structure like curtains.

They consist of a framing system (typically extruded aluminum), and panels between the frames (glass, or other materials for opaque sections of the wall).

The large quantity of glass in these systems may lead to increased heating and cooling loads in the space. High-performance glazing can control the loads to some degree, but not to the extent of insulated opaque (non-glass) wall constructions.

Finish materials

Finish materials are the the visible layers applied to a building's interior and exterior surfaces. They are chosen for aesthetic and functional purposes. Some types of interior finish surfaces used for wall, floor, and ceiling constructions include carpets, tiles, acoustic ceiling tiles, wood paneling, and paint (e.g. painted drywall for interior walls). Exterior finish materials may include roofing materials, siding, stucco, and others.

Insulating concrete forms (ICF)

ICF wall with foam cut away to show the inner structure and rebar. This cavity is filled with concrete to create the permanent wall. (Source: Wikipedia)

ICFs combine the insulating properties of foam with the strength of concrete. They are made from interlocking, hollow blocks of expanded polystyrene (EPS) foam, reinforced with steel rebar inserted into the cavities, and then concrete is poured into the forms.

The continuous foam insulation leads to good thermal performance, and the reinforced concrete provides structural strength and durability.. They are primarily used for exterior walls, and foundation walls.

Insulation

Insulation is a material designed to reduce heat transfer across surfaces. Several types of insulation are described below.

Batt insulation

Batt insulation installed between wall studs.

Batt insulation comes in rolls of flexible material designed to fit between framing such as wall studs, ceiling joists, and floor joists. It is commonly made of fiberglass, mineral wool, or natural fibers such as cotton or wool. Proper installation is important to avoid gaps and compressed areas which lead to reduced insulating effectiveness. Because it is installed between the studs or joists, thermal bridging can occur (heat transfer through structural studs that are not insulated.

Board insulation

Rigid foam board insulation has a high R-value per inch of thickness. It is often installed on the exterior of the wall framing, or above or below the roof deck, to create a continuous layer of insulation to reduce thermal bridging. Other applications include under concrete slabs, or to insulate below-grade walls.

Insulation boards can be made of several materials including:

• Expanded polystyrene (EPS) - lowest cost with moderate R-value
• Extruded polystyrene (XPS) - higher R-value than EPS, and moisture resistance for below-grade applications
• Polyisocyanurate (Polyiso) - highest R-value, and features a radiant barrier making it a good choice for roofs

Loose-fill insulation

Loose-fill insulation consists of small particles or fibers that are blown or poured into building cavities. It is often used in irregular or hard to reach spaces such as attics. Common materials include cellulose, fiberglass, rock wool, and others.

Spray foam insulation

Trained Spray Foam Applicator Applying Open Cell Foam. (Source: Wikimedia Commons)

Spray foam insulation is an expanding foam that provides insulation and air sealing. There are two types of spray foam insulation:

• Open cell - lower density and softer texture. Expands more than closed cell so it can be used to fill large, irregular, hard to reach areas.
• Closed cell - higher density, and provides a moisture barrier. Higher R-value compared to open cell spray foam.

Masonry

Masonry is a construction method where individual units like bricks, stones, or concrete blocks are laid together with mortar to build a structure. Masonry has high thermal mass which may be beneficial in climates that experience large temperature swings between day and night. Masonry walls require proper moisture management to prevent water penetration.

Concrete masonry units

Concrete masonry units (CMUs) are precast blocks made from concrete. They are available in various sizes and shapes including hollow and solid blocks. They are commonly used for exterior and interior walls.

Metal insulated panels

Metal insulated panels consist of two metal facings with a core of insulated foam. The metal facings provide durability and weather resistance while the core provides insulation. The outer surface can be made in a variety of aesthetic finishes. They are installed by interlocking the panels to each other and securing them together with fasteners. The interlocking panels are attached to structural framing members of the building.

Plastering

Plastering is the application of a thin layer of material (consisting of cement, gypsum, mud or other materials) to walls and ceilings. Cement, mud, and stucco are common for exterior use, and gypsum (plaster of Paris) is common for interior use due to its smooth finish.

Structural insulated panel

Structural insulated panels (SIPs) are a form of sandwich panel consisting of an insulated layer of rigid core sandwiched between two layers of board, commonly oriented strand board (OSB). The outer layers provide a base for attaching interior and exterior finishes. SIPs are commonly used for walls, roofs, and floors.

Spandrels

Spandrels refer to the area between the top of a window on one floor and the sill of the window above it. In skyscrapers and other tall buildings, the spandrel refers to the horizontal band or panel between the windows of successive floors.

Spandrel panels are used in curtain wall designs between successive floors to conceal structural elements, electrical, mechanical systems, and other elements between floors. Panels may be made of various materials including metal, opaque glass, composite panels with insulation, and others.

Wood

Wood-framed house construction. (Source: Wikimedia Commons)

Wood is one of the most prevalent construction materials and is used for many purposes such as structural, framing, finishes, walls, flooring, doors, trim, and decorative uses. Softwoods are commonly used for framing and sheathing, while hardwoods are often used for flooring.