Section I. - Importance of Siding

Siding is to a house as skin is to the human body. Siding protects the house against the elements and pests. It helps prevent moisture penetration and the growth of biological contaminants such as mold, dust mites and bacteria. These 3 types of biological contaminants have been known to cause allergic, respiratory, and other health problems in humans.

Choosing siding deserves careful consideration. Some sidings are good in dry climates, others in wetter climates. Some siding is better in windy conditions. And still others, like vinyl, are good in all types of weather conditions.

Rain, snow and frost are the moisture concerns. If rain, snow or frost get behind the siding, the moisture makes the wall sheathing soft, degrading the strength of the entire house frame.

Some of the common pests that may reside behind poor or inappropriate siding are dust mites, carpenter ants, and termites. Dust mites are a common allergy concern. Carpenter ants and termites, as they eat away at the home, undermine the strength of a wooden frame.

A carefully chosen siding, appropriate for your climate and the amount of care you are willing to devote to its maintenance, will not only give your house a new look, but protect your family's health and safety.

Section II. — Types of Siding

Seamless Siding Seamless siding is a unique product that produces a long lasting protective finish to your house in "seamless" sections. Made of steel, the sections of siding are produced right on-site from roll stock in a special machine that cuts the finished product to the exact measurements and contours of your house. Traditional vinyl siding comes in standard sized sections that are attached to the house and then cut to measurement to cover the longitudal sections. With Seamless siding the stock is produced to the exact length of the house wall or section.
Aluminum Aluminum is one of the metal sidings. It is more popular than steel because exposed areas of steel tend to rust. Aluminum siding comes in long panels with baked-on enamel finish that can be smooth or textured. Aluminum may dent and depending on how high or low the damaged panel is replacing it may be difficult. Aluminum is a good heat insulator and is very waterproof. Aluminum is composed of the same 3 basic parts as vinyl.
Rectangular Plank Perfectly rectangular wood planks are applied vertically with their ends butted together for a smooth look. The vertical joints of the planks are covered by long, narrow strips of wood called battens to help keep out moisture. The battens help give a vertical "rise and fall" look to the siding.
Clapboard Clapboard is rectangular planking applied horizontally and overlapped. Clapboard will not look as smooth as rectangular planking applied vertically. However, it can be given a smoother look if the edges of the plank are beveled or tapered.
Composition Board or Hardboard Planks or sheets of compressed wood fiber and weather resistant adhesive. Hardboard is a good choice in drier areas. The panels can be as long as 16 feet without any gaps. It can be made to look like clapboard if it is cut and applied horizontally.
Shingles Shingles are usually redwood, cedar or cypress. They are smooth sawn and of uniform size and shape. They are applied from the bottom up and overlap each other a bit as the next highest row is applied. Some people prefer to have their shingles overlap in various amounts to give a different look or texture. Shingles can be applied in a single course, where all shingles are exposed to the elements or a double course in which only the top layer of shingles is exposed. Shingles are prone to cupping, a rolling of the shingle toward the center, and checking, which is a cracking or splitting.
Shakes Shakes are a rough type of wooden shingle, usually redwood, cedar or cypress. They can be either: handsplit, handsplit and sawn on one side, or handsplit and sawn on both sides. They are non-uniform in size and shape and give a rustic look to the exterior of the home. Shakes can be applied in a single course, where all of them are exposed to the elements or a double course in which only the top layer is exposed. Shakes are prone to cupping, a rolling of the shake toward the center, and checking, which is cracking or splitting.
Stucco Stucco is very similar to plaster on an interior wall. Stucco, like vinyl, is a durable siding. It is composed of sand, water and cement. Today some stucco has an acrylic finish. In a traditional stucco application, wire mesh is attached to the sheathing and studs of the house. Two or three coats of various stucco mixtures are then applied over the wire mesh. Finally, the top coat of a stucco siding is applied with a smooth or textured finish.
Veneers Veneers are usually brick or stone. Veneers are applied one ply thick either as a whole house veneer or as an accent veneer. Veneers are applied from the ground up and are attached to the wall sheathing with brick ties. The brick ties expand and contract as the frame does to help keep the veneer from cracking. There is also an L-shaped metal flashing that runs underneath the brick and up the wall to keep water from the foundation. Veneers allow moisture to escape through their weep holes underneath the bottom course of the siding. Mortarless brick veneers are made of high strength tongue and groove concrete. Mortarless brick can be installed about 35% faster than conventional masonry. This type of siding is an excellent example of rain screening because water cannot penetrate the veneer.
Vinyl Vinyl panels are made of polyvinyl chloride and resemble wood. They act much the same way as aluminum but don't dent. If vinyl is scratched it doesn't need to be painted because vinyl doesn't rust and the color of the vinyl permeates the entire thickness of the panels. Vinyl siding comes in various lengths and widths. The average width of panes is between 6 ½ inches to 10 inches. Standard vinyl siding has 3 components: a nail hem at the top of the panel where the slots are located, the face which is the exposed area of the panel visible when installation is complete, and the buttlock, which is located on the bottom of the panel and locks into the previously installed panel. J-Channels and other accessories can be functional or aesthetic or both. These accents can cover seams, enclose eaves or overhangs, and provide an accent to the siding. Today's vinyl sidings come with lifetime warranties. Often these warranties are transferable if you sell your home.
Wood Plank Siding Planks for this type of siding can be cut perfectly rectangular, tapered or with special milled cuts. The special milled cuts are: V-Groove, channel, rabbeted bevel, shiplap, and drop. In addition to providing somewhat of a texture, special milled cuts also fit together in such a way as to protect joints from water infiltration.
Plywood Siding Plywood consists of 2 materials glued and veneered. The veneer is a slice or cut of wood of constant thickness. Plywood siding is more water resistant that indoor plywood.

Section III. — Types of Materials Used in Siding

Vinyl is made of polyvinyl chloride. It is widely used in construction today. It resembles wood and comes in various styles and colors. One of the advantages of vinyl is that the color of the vinyl permeates the thickness of panel making scratches almost unnoticeable. Vinyl responds well in a wide variety of temperatures and climates. Unlike aluminum, damaged panels can be replaced quite quickly. Unlike woods, vinyl has a relatively high ignition temperature of 736 F. Cedar will burn 2 ½ times faster and hardboard will burn 3 times faster than vinyl. This slower burn rate can give occupants more time to escape, in case of fire.

Stucco is a combination of sand, cement and water. It is waterproof and weatherproof. Though it is waterproof and weatherproof, it is also permeable to water vapor. It lets moisture escape from the walls.

Woods such as cedar, redwood and cypress are most often used as siding. Some woods are very attractive to animals or birds, like woodpeckers, whose pecking will make holes or otherwise damage siding. It is important to know about the area you live in before choosing a particular type of wood. Cedar is a large coniferous tree, its surface is soft and its grain is intricate. Cedar produces a natural tannin that is thought to be a natural insect repellent. These tannins can cause spots, especially after rain storms. The spotting will stop after about 3 years, once the wood is used to the weather conditions. Redwood is similar to cedar except in its color.

Aluminum is similar to vinyl but is very susceptible to dents, for example, when hit by a ball or leaned on. It is relatively low maintenance in the earlier years. It will need repainting when you touch it and a chalky residue appears on your finger. When it does need repainting it must be carefully prepared using a primer specifically selected for that aluminum. Once in a while a manufacturer will discontinue a pattern. It's a good idea to purchase several replacement panels when you make the initial siding purchase.

Brick is now more affordable due to the newer mortarless applications available. Mortarless brick is made of concrete.

Plywood. Common plywood veneers include southern yellow pine, Douglas fir and western red cedar. Plywood siding can be either smooth or roughhewn. One preferred plywood siding is T1-11, which is grooved to resemble lumber. Plywood siding applied horizontally is susceptible to water penetration. Two possible remedies for this are flashing behind the plywood or creating scarfed joints.

Section IV. — Siding Maintenance

Wood shakes and shingles
These should not be installed close to the ground where moisture might wick up behind them. If there is soil build up around the bottom of the wood siding it should be removed. Shakes and shingles will fade over time. And may fade unevenly depending on landscaping or nearness to other homes that might cause partial shade. Shakes and shingles can be painted or stained to help preserve them. Depending on the climate, painting may have to be done every 5-7 years and staining may have to be done every 3 years.

Wood planking will have to be painted. Again, it depends on the climate how long between paintings.

Composition board or hardboard must have a good deal of TLC, especially in wet climates. Composition board must be repainted more often than other wood sidings because it doesn't hold paint as well. If left exposed too long, the board will absorb moisture, expand and bow out. Unlike solid wood, which will shrink after it has expanded, hardboard will not. It may actually disintegrate. Make sure sprinklers and leaky downspouts don't wet the hardboard. You should always maintain 6-8 inches of clearance between the ground and the lowest board. Inspect the joints, the nails and the ends of planks. Caulk around cracked joints. Make sure nails haven't broken the surface finish or water will seep in.

Choosing a wood that is appropriate to your area is important to consider before you make your purchase. Some birds, like woodpeckers, have been known to punch away at the sides of homes. Should birds make holes in the wood they must be filled or replaced.

Brick and stone veneers may develop spalling. That means that the brick or stone or mortar may fall out or crumble. This is especially likely to occur where wall meets wall or at the bottom of the wall. One way to slow spalling is to clear any debris from underneath the lowest course of the veneer. Under this bottom course are weep holes that allow moisture to escape from behind the veneer. Another way to help prevent spalling is keeping vines off siding. As vines grow and spread on siding they actually do 2 things…they hold on to the mortar making it weak and they trap moisture next to the house. If cracks or spalling occurs it should be patched or replaced as soon as possible.

Mortarless brick will not have the problems that a brick and mortar siding does.

Stucco should be watched for cracks. All loose materials should be scraped from the cracks before caulking. Only use a paintable caulk.

Vinyl is easy to maintain. From time to time vinyl will have to be washed to eliminate dirt, dust, grass stains, mold or mildew. For heavier stains, vinyl siding can be cleaned with a soft cloth, or soft bristled toothbrush (if the surface is textured). Some of the more common cleaners that can be used on vinyl include: Fantastic®, Murphy's Oil Soap®, Lestoil®, Windex® and Soft Scrub®. Since vinyl and its accessories will melt when exposed to significant fire or flame, owners of vinyl siding should take care to keep grills and combustible materials, such as mulch and dry leaves, away from the siding.

Aluminum is easily maintained in the first few years. After that the color may fade or paint may peel, blister or crack. Aluminum should be watched for dents, which should either be repainted or the panel replaced. Aluminum may need to be cleaned to remove dirt, grass, or mildew. Pressure washing aluminum is possible but should first be done with plain water on low pressure. If low pressure doesn't seem to be making the area clean do a higher power test wash on an area that is less visible. The test wash is important because some pressure washers create enough pressure to break a 2 x 4. It is best to use a biodegradable detergent and hose it off with a light spray.

Plywood siding can expand and contract at different rates than the framing it is attached to. This expanding and contracting at different rates can cause nails to pull out, joints to pull apart and siding may fall off. Keep the surface finishes fresh or plywood siding will deteriorate, absorb moisture and warp. Once the warping starts, the grooves in the plywood will split allowing even more water to penetrate until the siding actually pushes away from the under ply.

Section V. — Siding Rating Systems/Specs

Vinyl Siding

HardBoard

Cedar Shakes and Shingles

Brick

Aluminum