Engineered Siding

DEFINITION

CONSIDERATIONS

COMMERCIAL STATUS

IMPLEMENTATION ISSUES

GUIDELINES

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CSI NUMBER

074 600
062 200
077 104

DEFINITION:

Engineered materials refer to the more efficient (less wasteful) process of using wood or other cellulose fibers bonded together to make a material shape. Reconstituted materials are more dense and offer increased longevity. Some products have wood fibers mixed with cement to form extremely durable exterior (fiber-cement) materials.

Fingerjointed material consists of using shorter pieces of wood glued together to make a longer piece. This technology makes use of wood that could previously be considered waste.

Recycled-content materials include substances that are salvaged from the waste stream such as sawdust and paper.

Tropical hardwood refers to wood harvested from the tropical forests that are being harvested in a destructive manner.

Recycled trim refers to the reuse of trim salvaged from building demolition.

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CONSIDERATIONS:

Reconstituted and recycled-content (engineered) siding materials offer superior longevity over wood siding. The increased density of the materials resists cracking and other deterioration. Fiber-cement materials, for example, offer very long warranties and have zero flamespread.

Steel and aluminum siding materials are predominantly fabricated from recycled material. Although the embodied energy is high when the materials are originally made, they require much less energy in a recycled form. They can also be recycled again after use in a building.

The use of domestic hardwoods for moldings and trim is noted since domestic hardwood trees are maturing at a faster rate than they are being removed (positive growth-removal rate).

Using recycled trim reuses trim in its same form, achieving the most resourceful recycling. Since trim is not structural, it is acceptable to use it in new construction. It will require going to different sources for material such as salvage businesses, and finding a large enough quantity of the same style can be challenging.

A very small percentage of tropical wood is sustainably managed and most of that is being used in furniture. The Resources section will note tropical species that are being sustainably managed.

There is not a problem with weak points in quality fingerjointed materials. For aesthetic reasons, fingerjointed material would go best where it will be painted.

	Commercial Status				Implementation Issues
	T E C H N O L O G Y	S U P P L I E R S	C O S T		F I N A N C I N G	A C C E P T A N C E	R E G U L A T O R Y
Siding
Trim
No Tropical Hardwood
Fingerjointed Trim
Domestic Hardwood
Recycled Trim
Reconstituted Trim

	Satisfactory
	Satisfactory in most conditions
	Satisfactory in Limited Conditions
	Unsatisfactory or Difficult

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COMMERCIAL STATUS

TECHNOLOGY:

The technology involved with these items is well-developed. There will be more reconstituted/recycled content materials entering the market.

SUPPLIERS:

Recycled-content materials are available primarily in aluminum. Reconstituted materials are available primarily in hardboards. All trim options are available including recycled trim. Fiber-cement siding is available.

COST:

Competitive.

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IMPLEMENTATION ISSUES

FINANCING:

There is not a financing issue.

PUBLIC ACCEPTANCE:

Highly durable engineered siding products are desirable.

REGULATORY:

Exterior wall coverings code regulations are presented in the 1992 CABO code Section R-503. Products purchased for siding must be installed according to the manufacturers instructions.

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GUIDELINES

Fiber-cement materials can be worked with woodworking tools.

Fiber-cement materials need an alkali resistant paint when painted. Some fiber-cement materials can be used unpainted if handled carefully to avoid scratching.

Fiber-cement materials are not brittle like earlier asbestos products.

Comments on products are included in the Resources Section.