An Introduction to Home Siding, CT: Function and Materials
Siding refers to the outermost layer of the sides of a building. 'Siding' and 'cladding' are sometimes used interchangeably, but really, siding is a type of cladding. Cladding is the material that covers a structure and it serves to protect the structure from the elements, and provide an attractive exterior finish. There are two types of cladding: masonry (stone, bricks, clay, concrete, stucco) and siding. Siding materials include wood, wood fiber, aluminum, vinyl, and fiber cement.
The Function of Siding
Siding is largely an aesthetic feature, but it is also an integral part of the wall system because it is the outermost shield. It must be able to withstand temperature changes, rain, snow, wind, and radiation, and protect the layers beneath from direct exposure. Siding can provide some insulation as well, but it is not meant to be airtight. Siding is part of a water-resistant barrier system. The siding sheds water and the rest of the system controls moisture by capillary action and diffusion to reduce the moisture absorbed by the structure itself.
Although cladding primarily sheds water, some cladding materials can also store water to a certain extent. Such materials are called 'reservoir cladding,' and include: stone, wood, fiber cement, stucco, concrete, and brick. The water they absorb can then enter the wall assembly as water vapor. Wall assemblies with these types of cladding should have a ventilated cavity and a vapor control layer with a drainage plane behind the cladding to prevent damage water damage inside the assembly. (See Diagram Above)
Once you choose your cladding material, it is critical that you discuss the design of the rest of the wall assembly with an experienced professional who is familiar with your climate. The permeability of the cladding will determine the types of barriers/retarders that your wall system needs, as well as where to put them to ensure that your wall can breathe.
Types of Cladding: (image via napco.plygem.com)
Masonry cladding, as seen in diagram above, is not very permeable, which must be accounted for in the design of the interior wall assembly.
Siding Materials are inherently "breathable" because there are gaps between the panels.
Vinyl siding has become one of the most widely used siding materials because it is affordable, easy to install, and comes in various thicknesses to suit the demands of different climates. They also come in a variety of colors and styles. Vinyl siding repels and directs water away from the building, while still allowing walls to "breathe" because air can escape between the siding joints.
Insulated Siding is a vinyl cladding that contains a pre-installed rigid foam plastic insulation.The most common type of insulation is expanded polystyrene (EPS).Insulated siding is designed to direct water away from and shield the walls, but it is not watertight, rather; it is designed to allow the materials beneath it to breathe.
Moisture does not have a significant effect on the thermal performance or dimensional stability of EPS, which enables the rain guard to exist on the inside of the insulation. The adhesives used to attach the insulation to the siding are flexible to allow for expansion and contraction in the siding caused by temperature changes.
Aluminum siding is able to resist changes in temperature, and it is durable. It comes in different patterns and can be painted, so it offers a lot of style options.
Wood siding is a nice looking finish and can be stained or painted pretty much any color, but it requires a fair bit of maintenance, it must be treated to avoid rot, and it can be costly.
Polyurethane/Polymer is sort of like 'man made' stone or brick, but it is lighter and easier to install. Its potential to expand and contract should be considered when designing and installing.
Wood Fiber Panels are 'man made' wood. They composed of wood fibers, wax, and resin that have been fused together. It looks like wood, but it requires less maintenance, costs less, and can tolerate humidity and temperature changes better than wood, even treated wood.
Fiber cement panels are composed off cement, sand, and cellulose fibers.
They resemble wood, but are low cost, low maintenance, weather resistant, and not vulnerable to damage from insects. They come in the form of shingles, boards, or panels and with many options for finishes and colors.
CertainTeed is a leading manufactoror of siding materials. Their guide can help you decide which material is right for you, or take a look at some siding projects completed by Fiderio & Sons.
Fiderio specializes in fiber cement, vinyl, and insulated vinyl siding installation. With more than 30 years of experience, we can answer any of your questions about siding and teach you about options that are suitable for Connecticut.