Walls & Ceilings - December 2009 - (Page 36)

the FINISH LINE BY ROBERT THOMAS Specifications for DAMAGE Foam shapes are often used at the perimeter of wall areas and are subjected to forces often not present in the fi eld of the wall. This includes leaning and standing on the shapes by maintenance people (such as window washers), as well as being leaned-against or bashed by ladders, swing stages or vehicles. Or sometimes foam shapes have items, such as banners, hung from them. Foam Shapes There’s hardly an EIFS job these days that doesn’t use foam shapes in some way. In fact, a lot of other nonEIFS claddings incorporate foam shapes as accents, such as shapes over stucco, block and concrete. Most foam shapes are made of EIFS, while others use non-EIFS materials to create hybrid EIFS-like shapes. Hybrid foam shapes are sometimes substituted for specified real EIFS foam shapes and sometimes this doesn’t work, as they do not perform the same or are incompatible in some way with adjacent materials. At times, the use of foam shapes is extensive on a given building, yet there are no standard guidelines as to what they are made of nor how they should be used. That’s about to change. an extrusion process, and attached to the wall at the job site. Basecoat is two to three times thicker than a normal basecoat. • Cast—very thick coating: Very thick cast stone shapes that are made off site that have a small foam core. Basecoat is 1/2 inch or more in thickness up to several inches. Essentially, cast stone in terms of weight. High strength and impact resistance. • Sprayed plastic basecoat: Contoured foam shapes that have a basecoat sprayed-on off site, and are attached to the wall and fi nished at the job site. MAXIMUM SIZE AND WEIGHT When the desired contoured foam shape is large, there’s a temptation to make the entire shape out of a gigantic block of foam. This eliminates the need to build up a complex matrix for framing and sheathing behind the outer foam layer, thus using a thin foam backing. Sometimes, these foam shapes are a foot or more in cross section. The code limits the maximum thickness to 4 inches for EIFS, yet sometimes these huge shapes do get installed. In the case of parapets, they hang off the top of the wall, and who is to know they are not safe to stand on? WHAT IS A FOAM SHAPE? This is a good question. There are many types, all of which tend to look the same from the outside. It’s sometimes difficult to tell what is the main wall on real EIFS, and what is a decorative add-on. In a sense, foam shapes are a separate industry from EIFS, yet they come together in the area of architectural decorative trim. The foam shape industry extends into nonarchitectural uses, such as decorations at theme parks and sculptures. For purposes of this article, here is an unofficial list of various foam shape-like materials, with comments: • “Real” EIFS: Made of the same materials as an EIFS wall cladding system, installed in layers at the job site. • Pre-basecoated foam: Made of contoured foam blocks that are covered with basecoat off site, and attached to the wall and finished at the site, using real EIFS materials. • Extruded—thick coating: Contoured foam shapes that have a thick basecoat (and perhaps the fi nish too), applied off-site using FIRE Interest in the fire performance of foam shapes was peaked last year when a major fire occurred on the top floor of the Monte Carlo casino in Las Vegas. The fire spread to lower floors and caused tens of millions of dollars in losses. An investigation was conducted and it appears that the affected areas, which caught fire due to nearby maintenance welding, behaved uncharacteristically for EIFS, perhaps as a result of the foam shape not being real EIFS. The rest of the building is real EIFS but the affected area had a hybrid EIFS-like foam shape system. This event has the potential for setting a precedent for further regulating the use of foam shapes, especially on large commercial buildings. ATTACHMENT Generally foam shapes are used as accents and account for a small percentage of the opaque façade. Occasionally, they are used for large wall areas and thus need to stand up to the wind forces of the main wall. This affects the way they are attached to the supporting wall. Some are attached with adhesives only, some with mechanical clips, and some with both. WARRANTY When combining multiple cladding systems on the same wall, the question arises for warranty purposes: “Whose wall system is it?” This applies even if the same contractor did all the work. With foam shapes, the shapes are vir- Note the thick coating, stone-like finish, and crisp edges. | Walls & Ceilings | December 2009

Table of Contents for the Digital Edition of Walls & Ceilings - December 2009

Walls & Ceilings - December 2009
Contents
Up Front
Trade News
Most Requested Products of 2009
Sixth Annual Excellence Awards
Move it on Up
City Central
The Finish Line
Smart Business
Trowel Talk
Straight Green
All in Agreement
Industry Voices
Toolbox
Information Showcase
Classified Marketplace
Advertiser Directory

Walls & Ceilings - December 2009

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