The Many Faces of Siding

by Kim Kinrade

The way a house is sided has an effect on many ways the home functions. Like the roof it protects the home from the elements but there other important ways why good siding is needed. For one it is a thermo-regulator, acting as barrier against wind and sun and protecting the insulation in the walls. Another job of siding is to prevent moisture vapor from entering the home and changing the relative humidity of the interior.

Settlers Perfected Siding

In the days of the pioneers logs provided some of the first building materials. Having thermal mass capabilities, which meant that they could regulate heat inside a structure, logs with mud sealing between them prevented the sun and wind from changing the inside temperature by deflection. Sod did the same thing for early prairie settlers. This was not the case with stone which, although blocked the elements, drew heat from the inside and allowed moisture to build up.

The early Dutch settlers began using a plank split from logs to put over a wooden frame. The way these pieces were split from a round log which made one edge thicker than the other. Using the thin edge to nail to the frame the thick side rested on the plank below angling out and deflecting water away from then structure. This was the beginning of clapboard siding which is still in high demand today.

In the American southwest the adobe structures used a clay coating to seal their rock structures. The Spanish influence embellished on this form of siding which had been in existence in other parts of the year for over three thousand years. Stucco, as it is now known, deflects heat and provides a seamless seal for the home.

Siding Materials

1.Stucco: Using a time-honored mix of limestone, sand and water stucco has survived through the ages as one of the most successful siding materials of all time. In the course of history straw and other fibers have been added for strength but it remained unchanged until modern times when Portland cement was substituted for pure lime. Properly adhered, stucco lasts a lifetime and never needs to be painted. For coloring the pigments can be added to the mixture.

The only downside to stucco is that it is porous and in wet areas it will attract mold and mildew, especially in the shady areas of the home. In addition, in northern areas the freeze-thaw cycle can cause cracks in the stucco.

2. Wood Clapboard: The original wood clapboard was pine and cedar, the latter of which could last as many as 50 years. Untreated, the other types of wood tended to rot or crack after dozen years or so which meant that the product had to be painted or oiled. Still there are a few historic homes dating back to the 1700's with the original clapboard siding.

Today, wood clapboard is pressure-treated and even pressure-painted. In addition, there are baffles on the backside to allow water to escape and prevent “wicking” which traps water in wood clapboards and causes rotting. Cedar is still popular and can be installed unfinished where it wioll weather to a fine silver color. Another wod product, vertical, tongue-and-groove siding is also popular for cottages.

3. Cement Fiber Clapboard: Using fiberglass fibers for reinforcing a Portland cement clapboard is becoming popular all over the country and in all weather regions. Because insects and water will not affect it cement fiber sidingt can be installed in areas of heavy moisture and in the southwest it acts like stucco in repelling the sun's heat to help the air conditioning systems. Cement fiber siding is shaped like traditional wood clapboard and even cuts and is installed the same. As well, it is completely fireproof.

4. Metal Siding: Both aluminum and steel are making inroads into the siding areas. Both products can be cut on site by the installers for a seamless length. Aluminum is powder-coated with an ultra-violet protective paint so the product will not fade like the previous generation of aluminum siding did. Steel by itself is corrosive but coated with a colored polyvinyl chloride compound it will last the life of the home. Both products are recyclable.

5. Vinyl Siding: Polyvinyl chloride (PVC) siding has pretty well taken over the market in many areas because it is cheap and comes in a wide variety of colors. The earlier versions faded and could be damaged by hail and heavy frost but new advances have led to a two-layered product which has an expensive anti-ultra violet coating on a strong PVC base. This means that the product is still inexpensive and low maintenance. The downside with PVC is that it must be put on loosely because the expansion and contraction would cause a tightly fastened system to buckle and warp. New foam-backed PVC siding offers heft and prevents warping. In addition, there are PVC shakes which mimic cedar and other wood shakes.