South Carolina Glass and Glazing Contractor Examination

In architectural glazing, what does bite mean?

• AThe depth of the glass edge captured in the frame rabbet, gasket pocket, or structural se…
• BThe air space between the two lites of an insulating glass unit
• CThe gap between the glass edge and the bottom of the rabbet
• DThe thickness of the weatherseal bead on the exterior glass face

A Columbia storefront lite of fully tempered glass arrives 1/2 in too wide. What is the correct field action?

• AScore and snap the lite on a cutting table the same way annealed glass is cut
• BReject or reorder the lite; fully tempered glass cannot be cut after it is tempered
• CGrind the long edge with an abrasive blade until it fits the opening
• DHeat the edge with a torch and break off the extra 1/2 in

Per GANA-type glazing practice, where should the two setting blocks under a rectangular lite normally be placed?

• ATight against each vertical jamb to lock the corners
• BStacked at midspan so the transom sees one concentrated reaction
• CUnder the head member to keep the lite from dropping
• DAt the approximate quarter points of the sill, equally spaced from the glass centerline

Relative to annealed float glass of the same thickness, what are the typical design-strength multipliers used for heat-strengthened and fully tempered glass?

• AHeat-strengthened about 2 times annealed; fully tempered about 4 times annealed
• BHeat-strengthened about 4 times annealed; fully tempered about 8 times annealed
• CHeat-strengthened equal to annealed; fully tempered about 2 times annealed
• DBoth heat-strengthened and fully tempered are treated as equal to annealed

What is an insulating glass unit (IGU)?

• AA single lite with a factory-applied Low-E coating on surface 1
• BTwo or more lites separated by a spacer, hermetically sealed, with desiccant in the spacer
• CLaminated glass with a polyvinyl butyral interlayer
• DWired glass with an embedded welded mesh

How should crates of architectural flat glass typically be stored on a South Carolina jobsite before installation?

• AFlat-stacked on the slab in direct sun so dirt can be washed off
• BLeaning loose against a wall at a steep angle with no edge protection
• CNear vertical on A-frames or stillages, blocked off the ground, with separators between l…
• DOn edge in a water-filled trough to keep the glass cool

Why is laminated glass often selected where post-breakage retention is required?

• AThe polyvinyl butyral or ionoplast interlayer holds fragments together after the glass br…
• BLaminated glass cannot break under any wind load
• CThe interlayer makes the glass four times as strong as fully tempered glass
• DLaminated glass is the only product that can be labeled as safety glazing

Why are ceramic-enamel spandrel lites usually specified as heat-strengthened or fully tempered rather than annealed?

• AAnnealed glass cannot receive a ceramic frit
• BThe dark coating absorbs solar heat and creates thermal stress that annealed glass is mor…
• CSpandrel glass is always a hazardous location under IBC 2406.4.1
• DHeat treatment is required so the lite can be field-cut to the opening

Why must weep holes in a wet-glazed or insulating-glass pocket remain open after setting blocks and sealant are installed?

• ATo pressurize the IGU cavity and keep the desiccant dry
• BTo provide indoor ventilation for the occupied room
• CTo drain water that enters the glazing pocket to the exterior
• DTo lock the setting blocks so they cannot move to the quarter points

What is the primary purpose of a Low-E coating on architectural glass?

• ATo make annealed glass qualify as safety glazing without tempering
• BTo reflect a large share of long-wave infrared energy and improve the U-factor and solar…
• CTo replace the desiccant inside an insulating-glass spacer
• DTo increase the glass bite required by the GANA pocket chart

A superintendent wants to use wired glass in a swinging office door because the wire will hold the shards. Does wired glass automatically satisfy IBC safety-glazing rules?

• AYes; any wired glass is accepted as Category II safety glazing
• BNo; wired glass must still pass CPSC 16 CFR Part 1201 or the applicable ANSI Z97.1 class,…
• CYes, but only if the wire is exposed on the long edges
• DNo, because wired glass is banned in every IBC opening

What is face clearance in a captured glazing pocket?

• AThe gap between the glass face and the stop, gasket, or pressure plate
• BThe gap between the glass edge and the rabbet bottom
• CThe depth of glass captured by the frame
• DThe visible glass width between the indoor and outdoor sightlines

What is the main job of edge blocks (side blocks or anti-walk blocks) in a metal glazing system?

• ATo carry the full dead load of the lite in place of setting blocks
• BTo keep the lite from shifting sideways in the opening under vibration, racking, or repea…
• CTo seal the IGU spacer from ultraviolet light
• DTo replace the need for weep holes at the sill

How does the typical breakage pattern of fully tempered glass differ from that of heat-strengthened glass?

• AFully tempered glass dices into small relatively dull particles; heat-strengthened glass…
• BHeat-strengthened glass dices into small particles; fully tempered glass breaks into long…
• CBoth products break into long dagger-like shards
• DNeither product can break once it has been heat-treated

When installing a large silvered glass mirror on a commercial interior wall, which handling rule is most important?

• AAlways lean the mirror coating-side down on bare concrete so the silver can cure
• BSupport the mirror uniformly, protect the silvered back from scratches and moisture, and…
• CScore the silvered face in the field if the mirror is 1/4 in too tall
• DUse a steel-on-glass setting block at midspan only

A 60 in by 120 in lite is set on two setting blocks. Using the common metal-system rule of 0.1 in of block length per square foot of glass, but not less than 4 in, what length should each block be?

• A3 in
• B4 in
• C5 in
• D12 in

A Greenville storefront takeoff lists eight vision lites, each 48 in wide by 60 in high. What is the total glass area to order, in square feet?

• A160 sq ft
• B240 sq ft
• C320 sq ft
• D23,040 sq ft

A typical 1/4 in monolithic lite is detailed with 3/8 in bite and 1/4 in edge clearance. What minimum rabbet depth is required to provide both dimensions?

• A3/8 in
• B1/2 in
• C5/8 in
• D1 in

A captured storefront opening has a daylight opening (DLO) of 46 in wide. The specified bite is 3/8 in on each vertical edge. What glass width should be ordered, ignoring cutting tolerance?

• A45-1/4 in
• B46 in
• C46-3/4 in
• D47-1/2 in

What Shore A hardness is commonly specified for elastomeric setting blocks (neoprene, EPDM, or silicone) in metal glazing systems?

• A20 ± 5
• B40 ± 5
• C85 ± 5
• D100 on the Shore D scale

A 1 in insulating-glass unit sits in a 1-1/8 in-wide glazing rabbet. Which setting-block width is the most appropriate GANA-type choice?

• A1/4 in, so water can flood around both sides of the block
• BAbout 1-1/16 in, slightly narrower than the rabbet and wide enough to support both lites
• C1-1/2 in, so the block is driven into both gaskets
• DEqual to the glass thickness of only the inboard lite

What is the primary purpose of edge clearance around a lite?

• ATo hide the IGU spacer from outdoor view
• BTo increase the structural bite used for wind-load resistance
• CTo create a capillary path that holds water in the rabbet
• DTo provide space for thermal movement and keep the glass edge off the frame

Using the GANA Glazing Manual-type pocket chart, which set of minimums is typical for 1/4 in monolithic glass?

• AFace clearance 1/8 in, edge clearance 1/4 in, bite 3/8 in
• BFace clearance 1/2 in, edge clearance 1/2 in, bite 1/16 in
• CFace clearance 0 in, edge clearance 0 in, bite 1 in
• DFace clearance 1/4 in, edge clearance 3/4 in, bite 1/8 in

Why do GANA-type charts typically call for about 1/2 in minimum bite on common insulating-glass units?

• ASo the frame sightline completely covers the spacer and edge seal and still provides pull…
• BBecause IGU glass is always 1/2 in thick
• CSo the setting blocks can be omitted
• DBecause 1/2 in bite replaces the need for a secondary IG seal

What is the difference between two-sided and four-sided structural silicone glazing (SSG)?

• ATwo-sided SSG captures two opposite edges in metal and structurally glazes the other two;…
• BTwo-sided SSG uses two beads of weatherseal; four-sided SSG uses four coats of paint
• CFour-sided SSG is only used on interior mirrors
• DThere is no difference; the terms are interchangeable

What is the principal difference between wet glazing and dry glazing?

• AWet glazing uses gunnable sealant or tape plus sealant; dry glazing uses preformed gasket…
• BWet glazing can only be done in the rain; dry glazing can only be done indoors
• CDry glazing is limited to plastic sheet; wet glazing is limited to wired glass
• DWet glazing never needs weep holes; dry glazing always omits setting blocks

How does a unitized curtain wall differ from a stick-built curtain wall?

• AUnitized systems arrive as factory-assembled framed modules; stick-built systems are asse…
• BStick-built systems are always structurally glazed; unitized systems never use silicone
• CUnitized walls can only be used below 30 ft; stick-built walls are only for high-rise
• DThere is no difference except the finish color

What is the idea behind a pressure-equalized rainscreen curtain-wall cavity?

• ASeal the outdoor face so perfectly that no air or water can ever enter
• BLet the mullion cavity reach outdoor pressure so rain is not driven through the outer joi…
• CPressurize the occupied room above outdoor pressure using the HVAC system only
• DOmit weeps so the cavity stays full of water as a thermal mass

Why do some specifications require a heat-soak test on fully tempered glass?

• ATo permanently soften the glass so it can be field-cut
• BTo reduce the risk of spontaneous breakage from nickel-sulfide inclusions by breaking def…
• CTo convert fully tempered glass into heat-strengthened glass
• DTo apply the Low-E coating after tempering

Two annealed lites have the same area and thickness. Lite A is 48 in by 48 in. Lite B is 24 in by 96 in. Which statement about uniform wind-load resistance is most accurate?

• ABoth lites have identical load resistance because area and thickness match
• BLite B (higher aspect ratio) typically has lower load resistance because the short span a…
• CLite B is always twice as strong because one side is twice as long
• DAspect ratio is ignored by ASTM E1300

Using the IBC Chapter 24 glass dead-load relationship of about 13 psf per inch of glass thickness, what is the approximate weight of a 4 ft by 8 ft lite of 1/4 in glass?

• A26 lb
• B52 lb
• C104 lb
• D416 lb

A Charleston curtain-wall lite measures 5 ft by 8 ft. The components-and-cladding design wind pressure is 40 psf. What total uniform wind force acts on that lite?

• A200 lb
• B320 lb
• C1,600 lb
• D16,000 lb

Under IBC Chapter 24, when is exterior glass treated as sloped glazing rather than vertical glass?

• AWhen it is sloped more than 15 degrees from vertical
• BWhen it is sloped more than 45 degrees from vertical
• COnly when it is a plastic skylight
• DOnly when the slope faces north

What is the usual distinction between aluminum storefront and a glazed curtain wall?

• AStorefront is typically a floor-supported, single-span entrance and window wall; curtain…
• BStorefront is always steel; curtain wall is always wood
• CCurtain wall can only be used on one-story buildings
• DThe two systems are identical except for the anodize color

A designer proposes point-supported (spider-fitting) glass at a Charleston lobby. What support condition does IBC 2403.2 require the contractor to respect?

• AAny unframed edge is automatically acceptable if the glass is 1/4 in annealed
• BWhere one or more sides are not firmly supported, a registered design professional must p…
• CPoint-supported glass is prohibited in South Carolina
• DOnly the glazing laborer on site may size the fittings

Why must field-applied silicone weatherseals be checked for compatibility with an insulating-glass unit's edge seal?

• ABecause every silicone attacks aluminum frames
• BBecause incompatible sealants can stain, soften, or lose adhesion at the PIB primary seal…
• CBecause compatibility testing replaces the need for weeps
• DBecause GANA requires oil-based caulk against every IGU

When patterned glass is designed for wind load under IBC 2404.3.3, which thickness is used in ASTM E1300?

• AThe thickest part of the pattern
• BThe average of the thickest and thinnest parts
• CThe thinnest part of the glass
• DAlways 1/4 in, regardless of the actual glass

A designer wants a deep sandblasted design on a large exterior lite. What structural effect must the glazing contractor expect?

• ASandblasting increases glass strength by putting the surface in compression
• BSandblasting reduces glass strength; IBC 2404.3.5 requires a reduced ASTM E1300 nonfactor…
• CSandblasting converts annealed glass into fully tempered glass
• DSandblasted glass is exempt from wind-load design

Setting blocks must be placed so they do not dam the sill. Which detail best satisfies GANA water-management practice?

• AUse full-width rectangular blocks that fill the rabbet from stop to stop and seal both en…
• BUse blocks that are slightly narrower than the channel, or chamfered/notched, and keep th…
• CButter the entire sill with sealant so no water can reach the weeps
• DStack two blocks at midspan directly over the weep

Why do fabricators often require extra face clearance for large fully tempered lites?

• ATempered glass shrinks after installation and needs room to grow thicker
• BRoller-wave bow and edge warp from the tempering process can make the lite thicker in the…
• CFace clearance replaces the need for bite on tempered glass
• DOSHA requires 1 in of face clearance on every tempered lite

A 4 ft (short side) by 7 ft structurally glazed lite must resist 30 psf. Using 20 psi allowable structural-silicone stress and converting units so bite is in inches, what minimum structural bite is required along the long edges?

• A1/8 in
• B1/4 in
• C3/4 in
• D3 in

A 20 ft aluminum curtain-wall mullion sees an 80°F temperature change. Using α = 12.8 × 10⁻⁶ in/in/°F, about how much will that mullion change in length?

• A0.02 in
• B1/4 in
• C1 in
• D2 in

IBC 2404.1 requires the load resistance of vertical glass under uniform load to be determined by ASTM E1300. Which comparison must be satisfied?

• AThe glass short-duration load resistance Fga must be at least the design wind load on the…
• BAny 1/4 in annealed lite is accepted up to 100 psf regardless of size
• COnly the IGU air-space thickness is checked; glass thickness is ignored
• DASTM E1300 replaces the need for safety glazing in doors

A Hilton Head elevation has twelve 36 in by 72 in lites and four 24 in by 36 in transom lites. What is the total glass area?

• A198 sq ft
• B216 sq ft
• C240 sq ft
• D2,592 sq ft

Why do insulating-glass manufacturers often size the secondary silicone seal of an IGU used in structural glazing for only about half of the design wind load?

• ABecause the inboard and outboard lites are assumed to share wind load about equally, so e…
• BBecause structural silicone is only rated at 10 psi in every specification
• CBecause the metal pressure plate carries the other 90 percent
• DBecause IG secondary seals are never allowed in SSG