Pharos adds Wallboards to Building Product Library

James Vallette | March 09, 2010 | Newsletter

This blog post, originally shared in the Pharos Signal, includes information about parts of Pharos that are no longer available. Please use it for historical reference and for the other useful information it contains.

Wallboards, our newest addition to the Pharos Building Product Library, are now ready for users to explore. The first batch of products focuses on products from three leading manufacturers, Georgia-Pacific,National Gypsum, and Temple-Inland. Over the coming weeks, we will add many more companies and products.

Wallboard is any flat board used to cover walls and partitions. These building materials also are called drywall, gypsum board, or plasterboard.

Drywall is most commonly comprised of a gypsum core, with Kraft paper facings and additives. There are several types of modifications. The most common is Type-X, which is fire-resistant board. Other variations include moisture-resistant (MR, or "green") board, acoustical board, insulating board, and fiberboard, which can include recycled newsprint fibers and perlite filler. Gypsum board is occasionally backed not with paper, but with vinyl or foil.

These are ubiquitous materials. Everyone specifies them. Over 95% of the walls used in the US and Canada are finished with gypsum board. This includes residential, commercial, and institutional buildings.

As this category is unveiled, Pharos users will encounter a surprisingly diverse range of content and scores. We will explain the significances of these variations in the product records and in Signal articles in the coming weeks.

Among the issues:


  • Recycled content: There are great variations in recycled content, ranging from none to as high as 99% post-industrial material. Natural (mined) gypsum remains the predominant material used, but synthetic gypsum is capturing an increasing share of the market. Synthetic gypsum is primarily obtained from Flue Gas Desulfurization (FGD) units of recently retrofitted coal-fired power plants. We will explore some of the costs and benefits of using FGD-derived waste in building materials.
  • Additives: Wallboard manufacturing uses additives, such as dispersants, accelerators, and set retarders. The most hazardous additive in gypsum board manufacturing is a naphthalene sulfonic acid / formaldehyde copolymer used as a dispersant. Lignosulfonates offer less hazardous, more bio-based, alternatives. These additives raise both manufacturing and indoor air quality concerns.
  • IAQ: Some brands of gypsum board have been certified for Indoor Air Quality attributes, including passing California Section 01350 testing, but there are considerable indoor air quality issues. Testing by the state of California and the U.S. EPA has identified formaldehyde emissions from many new wallboard products.
  • Made in China: Regulatory scrutiny of the wallboard industry has increased since homeowners began complaining of sickness and other effects from recently installed wallboard that was made in China. We will attempt to characterize what is known about China-made wallboard, and where it is in the U.S. marketplace.


Pharos' ever-expanding library of building material evaluations now includes five product categories and over 200 products. We will be adding more categories later this month. Thank you for subscribing and supporting our non-profit efforts to shed light on the building material marketplace.