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LA Roofing Contractor practice questions

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Question 1Roofing Materials, Systems and Installation Practices

What is the primary purpose of installing underlayment beneath asphalt roof shingles?

  1. To bond the shingles to the sheathing
  2. Acts as a secondary water barrier Correct answer.
  3. To provide the finished walking surface
  4. To stiffen the roof deck between rafters

Explanation

Shingles are the primary roof covering, and the underlayment beneath them is a secondary barrier that sheds water that gets past the shingles. Underlayment is also required as a separation layer over the sheathing. It has no structural or adhesive role.

Question 2Roofing Materials, Systems and Installation Practices

When fastening asphalt shingles by hand, the nail head should be:

  1. Flush with the surface, not cutting the mat Correct answer.
  2. Driven at a 45-degree angle through the tab
  3. Left protruding about 1/8 inch above the surface
  4. Driven until the head crushes the mat

Explanation

Fasteners must be driven straight and flush with the shingle surface so the head bears on the mat without cutting into it. Overdriving tears the mat and underdriving leaves the head high, and both conditions reduce wind resistance and can create leak paths.

Question 3Roofing Materials, Systems and Installation Practices

On roof slopes of 4:12 or steeper, side laps of asphalt-saturated felt underlayment should be at least:

  1. 12 inches
  2. 6 inches
  3. 2 inches Correct answer.
  4. 4 inches

Explanation

Felt underlayment on slopes of 4:12 and steeper is lapped 2 inches on side laps, with end laps increased to about 4 inches. All laps must face downslope so water runs over, not into, the lap. On slopes between 2:12 and 4:12 double coverage with much wider laps is required.

Question 4Roofing Materials, Systems and Installation Practices

Attic ventilation primarily serves to:

  1. Eliminate the need for underlayment
  2. Support the roof sheathing panels
  3. Warm the attic in winter to prevent condensation
  4. Remove heat and moisture from the attic Correct answer.

Explanation

Ventilation moves outside air through the attic to carry away heat that degrades shingles and moisture that can condense on cold framing and sheathing. Balanced intake at the eaves and exhaust high on the roof are both required for it to work. Venting does not replace any roofing component.

Question 5Roofing Materials, Systems and Installation Practices

Roof flashing is installed primarily to:

  1. Replace the need for underlayment at the eaves
  2. Provide a decorative transition between planes
  3. Increase the wind uplift rating of the roof covering
  4. Direct water away from joints, penetrations, and walls Correct answer.

Explanation

Flashing is the water-shedding material at intersections and penetrations where the field covering cannot be continuous, such as walls, chimneys, valleys, and pipes. It must be layered with the shingles so each course laps over the one below. Flashing is a waterproofing detail, not an aesthetic or structural one.

Question 6Roofing Materials, Systems and Installation Practices

The two recognized methods of constructing an asphalt shingle valley are:

  1. Woven and rolled
  2. Laced and soldered
  3. Woven and cut Correct answer.
  4. Standing and blind

Explanation

Shingle valleys are built either woven, where courses from both roof planes are interwoven across the valley, or cut, where shingles are run through the valley and trimmed along a chalk line to form an open channel. Both rely on a valley lining beneath the shingles. The choice depends on slope, shingle type, and local practice.

Question 7Roofing Materials, Systems and Installation Practices

Vertical joints between shingle courses must be offset because staggering:

  1. Allows the shingles to expand freely in the summer
  2. Reduces the total number of nails required
  3. Stops water from tracking down a continuous seam Correct answer.
  4. Matches the direction of the prevailing wind

Explanation

Offsetting the joints keeps cutouts and end joints from aligning into a continuous vertical line that water could follow down to the deck. It also spreads fasteners so no two courses share the same nailing line. Staggering does not change the required number of fasteners.

Question 8Roofing Materials, Systems and Installation Practices

Metal drip edge along the eave is installed to:

  1. Stop water wicking under the shingles Correct answer.
  2. Replace the starter strip on the rake edge
  3. Support the weight of the gutter
  4. Cover the ridge vent opening

Explanation

Eave drip edge projects over the fascia and gutter so runoff leaves the roof edge instead of curling back along the deck. It also protects the wood edge and gives the starter course a straight line. At the eaves it goes under the underlayment; at the rakes it goes over it.

Question 9Roofing Materials, Systems and Installation Practices

In an area where the design wind speed requires enhanced fastening, asphalt shingles are typically attached with:

  1. Staples placed at each cutout
  2. Two nails per shingle in the tab centers
  3. Six nails placed in the nailing zone Correct answer.
  4. Adhesive only, with no fasteners

Explanation

The standard schedule is four fasteners per shingle, but high-wind zones call for six fasteners per shingle placed within the manufacturer's nailing zone above the exposure line. The extra fasteners at the ends of each shingle resist tab uplift and peel. Fastener type must also meet the manufacturer's specification, usually galvanized roofing nails.

Question 10Roofing Materials, Systems and Installation Practices

The starter course at the eave is installed to:

  1. Hold the underlayment in place
  2. Seal the cutouts at the eave Correct answer.
  3. Increase the fire rating of the roof
  4. Provide a bonding surface for the gutter

Explanation

The first shingle course sits with its cutouts over the eave, and a starter strip fills those openings so water and wind cannot enter under the tabs. Starter also gives a straight, sealed edge along the eave and rake. It is installed over the underlayment and beneath the first full course.

Question 11Roofing Materials, Systems and Installation Practices

Asphalt shingles should not be installed on roof slopes below:

  1. 1:12
  2. 3:12
  3. 2:12 Correct answer.
  4. 4:12

Explanation

Shingles are a steep-slope covering limited to slopes of 2:12 and greater, and between 2:12 and 4:12 a double underlayment is required. Below 2:12 the roof is treated as low slope and needs a membrane or other watertight system. The steeper the slope, the faster water drains and the more reliably the shingles shed it.

Question 12Roofing Materials, Systems and Installation Practices

Thermoplastic polyolefin (TPO) single-ply membrane seams are normally joined by:

  1. Hot-air welding Correct answer.
  2. Mechanical compression bars
  3. Contact adhesive
  4. Solvent welding

Explanation

TPO is a thermoplastic, so seams are fused with hot air and pressure to form a homogenous bond. The finished seam is normally probed or peeled to confirm the weld. Solvent welding and contact adhesives are used with other membrane chemistries, not TPO.

Question 13Roofing Materials, Systems and Installation Practices

SBS-modified bitumen cap sheets are typically applied:

  1. Stapled at 6 inches on center
  2. Only with solvent-welded seams
  3. Dry-laid over felt without adhesion
  4. By hot mopping or cold adhesive Correct answer.

Explanation

Modified bitumen sheets are set in hot asphalt, torched, or adhered with cold adhesive, depending on the product and specification. The method must follow the manufacturer's published instructions to keep the warranty valid. Fastening is limited to base sheet attachment where the system calls for it.

Question 14Roofing Materials, Systems and Installation Practices

Counterflashing at a masonry chimney is installed to:

  1. Embed its top edge in a reglet in the masonry Correct answer.
  2. Take the place of base flashing at the chimney
  3. Support the chimney cap and flue tile
  4. Seal the chimney flue against rain

Explanation

Counterflashing laps over the base flashing and its upper edge is set into a reglet cut in the masonry and sealed, so water cannot get behind the flashing. Base flashing still turns up against the chimney below it. Together they form a shingle-lapped, two-piece detail that can be maintained.

Question 15Roofing Materials, Systems and Installation Practices

A ridge vent works with soffit vents because:

  1. Air enters at the ridge and exits at the soffit
  2. No intake openings are needed with a ridge vent
  3. Air enters at the soffit and exits at the ridge Correct answer.
  4. The attic air is mechanically dehumidified

Explanation

Ventilation depends on a balanced flow: cooler air enters low at the soffit, warms in the attic, and rises out at the ridge. Without adequate intake area the ridge vent cannot move air, and it may even draw air down the vents. Net free vent area must be balanced between intake and exhaust.

Question 16Roofing Materials, Systems and Installation Practices

When installing through-fastened metal roof panels, the screws should be driven:

  1. Through the high rib with a plain screw
  2. Loosely, so panels can expand and contract
  3. Only at the pan, with no washer
  4. With a sealing washer snug against the panel Correct answer.

Explanation

Each fastener carries a neoprene or EPDM washer that must be compressed snugly against the panel, not crushed, to seal the hole. Fastener location follows the panel manufacturer, usually on the rib or at a specified flat. Over-driving deforms the washer and under-driving leaves the hole open, and either causes leaks.

Question 17Roofing Materials, Systems and Installation Practices

Where wood structural panel roof sheathing is used as a base for asphalt shingles, the minimum nominal thickness is generally:

  1. 3/8 inch Correct answer.
  2. 1/4 inch
  3. 5/16 inch
  4. 1/2 inch

Explanation

Model codes set the minimum roof sheathing thickness at 3/8 inch nominal with an adequate span rating, and the panel span rating must match rafter spacing. A 3/8-inch panel rated for 24-inch spacing can be used where the rating permits. Thinner panels deflect and will not hold fasteners reliably under shingle loading.

Question 18Roofing Materials, Systems and Installation Practices

In an open metal valley, the valley lining is placed:

  1. Beneath the shingles, centered on the valley Correct answer.
  2. Only across the bottom third of the valley
  3. Under the sheathing, between deck and rafter
  4. Over the finished shingles, sealed at the edges

Explanation

Valley lining goes over the underlayment and under the shingles, centered on the valley line and extending up each roof plane. Shingles from both planes are then cut back to leave the metal exposed as the drainage channel. The lining must lap over the underlayment so any water that bypasses the shingles is directed into the valley.

Question 19Roofing Materials, Systems and Installation Practices

Under clay or concrete roof tiles on a steep slope, the underlayment acts as:

  1. A substitute for battens
  2. A vapor barrier only
  3. A bonding surface for mortar
  4. The main waterproofing layer Correct answer.

Explanation

Tile is a water-shedding but not watertight covering, so the underlayment must provide the actual waterproofing beneath it. Any wind-driven or capillary water that passes the tile is carried down the underlayment to the eave. This is why underlayment grade and fastening are critical on tile roofs.

Question 20Roofing Materials, Systems and Installation Practices

A cricket (saddle) is required on the upslope side of a chimney when the chimney is wider than:

  1. 48 inches
  2. 12 inches
  3. 24 inches
  4. 30 inches Correct answer.

Explanation

When the roof slope runs into a chimney that is more than 30 inches wide, a cricket is built to divert water around the chimney instead of letting it pond against the back face. Narrower chimneys can be handled with backer flashing alone. The cricket must be flashed into the chimney like a small roof.

Question 21Roofing Materials, Systems and Installation Practices

A Class A roof covering rating indicates that the assembly:

  1. Has passed a two-inch hail impact test
  2. Resists wind uplift up to 110 mph
  3. Best resists external fire Correct answer.
  4. Applies only to commercial roof systems

Explanation

Class A, B, and C ratings come from external fire exposure testing of the complete roof assembly, with Class A being the most severe. The rating reflects the covering plus underlying materials, not just the surface product. Wind and hail performance are rated separately.

Question 22Roofing Materials, Systems and Installation Practices

In shingle installation, a "high nail" is a fastener that is:

  1. Driven above the nailing zone Correct answer.
  2. Driven below the exposure line
  3. Placed anywhere in the nailing strip
  4. Driven through the cutouts between tabs

Explanation

A high nail misses the nailing area of the shingle beneath it, so it does not lock the courses together and the head is not covered by the next course. The result is reduced uplift resistance and an exposed penetration that can leak. Nails must fall within the manufacturer's nailing zone on every shingle.

Question 23Roofing Materials, Systems and Installation Practices

Which practice most reduces the risk of condensation on the underside of roof sheathing in a vented attic?

  1. Sealing air leaks and venting fans outside Correct answer.
  2. Adding a second layer of shingles
  3. Closing soffit vents to keep the attic warmer
  4. Installing carpet over the attic floor

Explanation

Most attic moisture comes from household air leaking through ceiling penetrations, so air sealing plus ducting bath and kitchen exhaust outdoors removes the source. Balanced ventilation then keeps the deck dry. Warming the attic or trapping more moisture only shifts the problem.

Question 24Roofing Materials, Systems and Installation Practices

The self-sealing strip on an asphalt shingle is intended to:

  1. Waterproof the nail penetrations
  2. Provide a Class A fire rating
  3. Bond the shingle to the course below Correct answer.
  4. Replace nails on steep slopes

Explanation

Heat from the sun softens the adhesive strip so each shingle bonds to the course beneath it, which is what resists wind uplift and tab flutter. Mechanical fasteners remain the primary attachment. In cold weather the strips may not seal without time or hand sealing where the manufacturer permits.

Question 25Roofing Materials, Systems and Installation Practices

In a built-up roof, the number of plies refers to:

  1. The number of insulation boards
  2. The deck thickness in eighths of an inch
  3. The number of gravel layers applied
  4. The felt sheets embedded in bitumen Correct answer.

Explanation

A built-up roof is made of alternating layers of bitumen and reinforcing felt; a 4-ply roof has four felt plies fully embedded in bitumen. The plies plus surfacing produce the finished membrane's waterproofing and durability. Gravel or coating is the surfacing, not a ply.

Question 26Roofing Materials, Systems and Installation Practices

What is the minimum headlap for asphalt strip shingles installed on a steep-slope roof?

  1. 4 inches
  2. 1-1/2 inches
  3. 1 inch
  4. 2 inches Correct answer.

Explanation

Headlap is the amount by which a shingle course is covered by the second course above it, and for standard strip shingles it works out to the shingle length minus twice the exposure. Model codes and shingle manufacturers require at least 2 inches of headlap so the vertical joints between shingles are shielded from water running down the roof.

Question 27Roofing Materials, Systems and Installation Practices

An ice dam protection membrane at the eave of a roof must extend from the roof edge up the roof to a point that is:

  1. 6 inches upslope of the eave edge
  2. At the ridge line
  3. At least 12 inches upslope of the eave edge
  4. At least 24 inches measured horizontally inside the exterior wall line of the building Correct answer.

Explanation

The ice barrier is intended to back up the roof covering where snow melt can refreeze at the cold eave. Codes require it to run from the eave edge to a point at least 24 inches measured horizontally inside the exterior wall line, which places the membrane over the heated portion of the building.

Question 28Roofing Materials, Systems and Installation Practices

EPDM single-ply roof membrane seams are normally joined by:

  1. Bonding with a splice tape or contact adhesive Correct answer.
  2. Stapling the lap and coating it with roofing cement
  3. Hot-air welding of the overlapping edges
  4. Soldering the seam with a metal-filled rod

Explanation

EPDM is a thermoset rubber, so its seams cannot be fused by heat; they are joined with a cleaned and primed lap using a butyl splice tape or a contact adhesive. Only thermoplastic membranes such as TPO and PVC are joined by hot-air welding.

Question 29Roofing Materials, Systems and Installation Practices

Steep-slope underlayment beneath asphalt shingles is installed:

  1. Vertically, running from rake to rake
  2. Starting at the ridge and working down to the eave
  3. Parallel to the eave, starting at the eave, with each upper course lapping over the lower course Correct answer.
  4. Only in valleys and around penetrations

Explanation

Underlayment is applied shingle-fashion, beginning at the eave and working upward so that each course overlaps the one below. This orientation makes water that gets past the shingles flow over the laps rather than being driven into them.

Question 30Roofing Materials, Systems and Installation Practices

In a balanced attic ventilation system, the net free vent area is distributed so that:

  1. All of the venting is located at the soffits
  2. Roughly half is intake at the soffits and half is exhaust at or near the ridge Correct answer.
  3. All of the venting is located at the ridge
  4. Roughly 75 percent is intake at the soffits and 25 percent is exhaust

Explanation

A balanced system provides a continuous path from low intake vents to high exhaust vents. Splitting the net free area roughly 50/50 between soffit intake and ridge exhaust keeps air moving across the underside of the sheathing without pressurizing or depressurizing the attic.

Question 31Roofing Materials, Systems and Installation Practices

The general code rule for attic ventilation requires a minimum net free vent area of 1 square foot for each:

  1. 600 square feet of ceiling area
  2. 300 square feet of ceiling area
  3. 150 square feet of ceiling area Correct answer.
  4. 50 square feet of ceiling area

Explanation

The baseline ratio is 1 square foot of net free vent area per 150 square feet of ceiling area. A ratio of 1 to 300 is permitted only where a vapor retarder is installed on the warm side or the vents are balanced and located as the code allows.

Question 32Roofing Materials, Systems and Installation Practices

The minimum nail used to apply asphalt shingles to a new wood roof deck is:

  1. A 2-inch drywall screw
  2. A 1-inch, 12-gauge roofing nail
  3. A 3/4-inch-long, 11-gauge roofing nail with a 3/8-inch head Correct answer.
  4. A 1-1/4-inch common wire nail

Explanation

Roofing nails for asphalt shingles must have a large flat head to hold the shingle without tearing and enough shank to penetrate the deck. The code minimum for a new wood deck is an 11-gauge nail at least 3/4 inch long with a head not less than 3/8 inch in diameter.

Question 33Roofing Materials, Systems and Installation Practices

At the eave, the roof underlayment should be installed:

  1. Butted to the drip edge with no overlap
  2. Only on the rakes, not at the eaves
  3. Over the flange of the metal drip edge Correct answer.
  4. Under the flange of the metal drip edge

Explanation

The standard detail places the underlayment over the drip edge at the eave and under the drip edge at the rakes. This lets any water that reaches the underlayment drain out over the eave edge rather than being trapped behind the metal.

Question 34Roofing Materials, Systems and Installation Practices

Asphalt shingles are to be installed on a roof with a slope of 3:12. What is required for the underlayment?

  1. No underlayment, because the shingles are self-sealing
  2. A single layer of rosin-sized building paper
  3. A single layer of No. 15 felt
  4. Two layers applied shingle-fashion, or a single layer of self-adhering membrane Correct answer.

Explanation

Between 2:12 and 4:12 the shingles are more vulnerable to wind-driven rain and capillary movement, so the code requires a double layer of underlayment lapped shingle-fashion or one layer of self-adhering membrane. A single layer is adequate only on slopes of 4:12 and steeper.

Question 35Roofing Materials, Systems and Installation Practices

Standing-seam metal roof panels are held with concealed clips instead of fasteners driven through the panel face primarily because the clips:

  1. Permit the panels to expand and contract with temperature changes Correct answer.
  2. Reduce the total material cost of the roof
  3. Eliminate the need for underlayment beneath the panels
  4. Raise the fire-resistance classification of the assembly

Explanation

Metal panels move significantly as they heat and cool, and a fixed fastener through the panel face would restrain that movement and elongate or tear the fastener hole. Concealed clips hold the seam while allowing the panel to slide, keeping the roof watertight over many thermal cycles.

Question 36Roofing Materials, Systems and Installation Practices

When wood shakes are installed on a roof, adjacent shakes in a course should be:

  1. Spaced roughly 1/4 inch to 3/8 inch apart Correct answer.
  2. Installed with the thin edge at the butt
  3. Butted tightly against one another
  4. Spaced roughly 1 inch apart

Explanation

Shakes swell when wet, so a small gap of about 1/4 to 3/8 inch is left between adjacent units to allow for that movement. Butting them tightly causes buckling and cupping, while wide gaps expose the underlayment excessively.

Question 37Roofing Materials, Systems and Installation Practices

A valley lining of roll roofing or sheet metal used under asphalt shingles is typically:

  1. 24 inches wide, centered on the valley line
  2. 18 inches wide, centered on the valley line
  3. 12 inches wide, centered on the valley line
  4. 36 inches wide, centered on the valley line Correct answer.

Explanation

Valley lining must extend well beyond the centerline of the valley on both sides so that water converging from two roof planes stays on the lining. The customary minimum is a 36-inch-wide strip centered on the valley, giving 18 inches of protection on each slope.

Question 38Roofing Materials, Systems and Installation Practices

Wood structural panel roof sheathing should be installed with:

  1. A 1/2-inch gap between panel edges
  2. Gaps provided only at the ridge line
  3. A 1/8-inch gap between panel edges Correct answer.
  4. Panels tightly butted at all edges

Explanation

Panels need a small expansion allowance, and a 1/8-inch gap at the edges is the standard detail. Tight butting can cause the panels to buckle or ridge at the joints as they absorb moisture, and oversize gaps weaken the diaphragm.

Question 39Roofing Materials, Systems and Installation Practices

Base flashing where a roof meets a vertical wall must extend up the wall not less than:

  1. 10 inches above the roof surface
  2. 2 inches above the roof surface
  3. 4 inches above the roof surface Correct answer.
  4. 1 inch above the roof surface

Explanation

Base flashing is turned up the vertical surface at least 4 inches above the roof so that water standing or backing up at the juncture cannot overtop it. Counterflashing then laps over the top of the base flashing to shed water away from the wall.

Question 40Roofing Materials, Systems and Installation Practices

A ballasted single-ply EPDM roof assembly is normally designed with ballast weight of about:

  1. 2 pounds per square foot
  2. 30 pounds per square foot
  3. 5 pounds per square foot
  4. 10 pounds per square foot Correct answer.

Explanation

Ballast holds the loose-laid membrane down against wind uplift, and about 10 pounds per square foot is the typical design load for standard ballasted systems. The required weight is increased in high-wind zones or reduced where the membrane is also adhered or mechanically attached.

Question 41Roofing Materials, Systems and Installation Practices

Hip and ridge cap shingles are applied:

  1. Before the field shingles are installed
  2. Starting at the bottom of the hip and working upward, with laps turned away from the prevailing wind Correct answer.
  3. From both ends toward the center of the ridge
  4. From the ridge down toward the eave

Explanation

Hip and ridge caps are laid shingle-fashion from the low end upward so each piece overlaps the one below it. The laps are oriented away from the prevailing wind so wind-driven rain is not forced into the joints.

Question 42Roofing Materials, Systems and Installation Practices

In a coastal environment, fasteners used for metal roof panels should be:

  1. Plain steel coated with roofing cement
  2. Electroplated galvanized steel
  3. Aluminum fasteners in contact with preservative-treated wood
  4. Hot-dip galvanized or stainless steel Correct answer.

Explanation

Salt-laden air rapidly corrodes thin zinc coatings, so coastal roofs require heavier protection such as hot-dip galvanizing or stainless steel. Dissimilar metals must also be kept apart to avoid galvanic corrosion at the fastener.

Question 43Roofing Materials, Systems and Installation Practices

The minimum roof slope normally permitted for through-fastened, exposed-fastener metal roof panels is:

  1. 6:12
  2. 3:12 Correct answer.
  3. 1:12
  4. 1/4:12

Explanation

Exposed-fastener panels rely on laps and washered screws rather than raised seams, so they need enough slope to shed water quickly. Three inches per foot is the usual minimum, while standing-seam panels with raised seams can go down to about 1/4:12.

Question 44Roofing Materials, Systems and Installation Practices

Step flashing where a roof meets a sidewall is installed:

  1. As one continuous strip running the length of the wall
  2. Above the siding and beneath the shingles
  3. In individual pieces, one for each shingle course, woven with the roof shingles Correct answer.
  4. Only at the eave end of the wall

Explanation

Step flashing is made up of small L-shaped pieces, one per shingle course, each lapped by the shingle above and by the next piece upslope. This stepped arrangement lets water drain down the wall line without a continuous seam that could admit water.

Question 45Roofing Materials, Systems and Installation Practices

Fasteners used to attach concrete roof tiles to the roof structure should be:

  1. Staples driven through the headlap only
  2. Corrosion-resistant nails or screws driven snug but not overdriven Correct answer.
  3. Electroplated common nails driven flush with the tile surface
  4. Reliance on roofing cement alone, without fasteners

Explanation

Tiles are fastened with corrosion-resistant nails or screws, and the fastener head must bear on the tile without being driven so far that it cracks or breaks the tile. Overdriving is a common cause of cracked tiles and broken fastening.

Question 46Roofing Materials, Systems and Installation Practices

Standard slate roofing is laid with a headlap of not less than:

  1. 3 inches Correct answer.
  2. 2 inches
  3. 6 inches
  4. 1 inch

Explanation

Slate is a rigid, impervious material that relies on lap rather than on a continuous membrane to shed water. The recognized minimum headlap is 3 inches, and the required lap increases as the roof slope decreases.

Question 47Roofing Materials, Systems and Installation Practices

Under clay or concrete roof tiles on a slope of 4:12 or greater, the minimum underlayment is generally:

  1. A single layer of rosin-sized building paper
  2. One layer of No. 30 felt or an approved equivalent Correct answer.
  3. No underlayment, provided the tiles are mechanically fastened
  4. One layer of No. 15 felt

Explanation

Tiles shed most water but are not themselves watertight at the laps and at broken units, so a heavy underlayment is required. On slopes of 4:12 and greater the standard minimum is one layer of No. 30 felt or an approved equivalent, with heavier protection required on lower slopes.

Question 48Roofing Materials, Systems and Installation Practices

Gravel or slag surfacing on a built-up roof is applied at approximately:

  1. 300 pounds per square
  2. 400 pounds per square Correct answer.
  3. 100 pounds per square
  4. 200 pounds per square

Explanation

Loose gravel or slag is embedded in a flood coat of bitumen at about 400 pounds per square, which gives a dense, continuous protective layer. The surfacing shields the bitumen from ultraviolet light and adds fire resistance and some wind resistance.

Question 49Roofing Materials, Systems and Installation Practices

Where a low-slope membrane is turned up a wall, the top edge of the flashing is secured by:

  1. Roofing nails driven through the membrane only, spaced 12 inches on center
  2. A bead of roofing cement alone
  3. A termination bar or reglet with fasteners, sealed with an approved sealant Correct answer.
  4. Folding the membrane into the counterflashing without any fastening

Explanation

The top of a membrane flashing needs continuous, mechanical compression to prevent water from creeping down behind it. A termination bar or a recessed reglet with regularly spaced fasteners, sealed with an approved sealant, provides that continuous clamping action.

Question 50Roofing Materials, Systems and Installation Practices

A cant strip at the base of a built-up roof flashing is used to:

  1. Hold the gravel surfacing back from the wall
  2. Serve as a nailer to which the counterflashing is fastened
  3. Increase the thermal resistance of the roof assembly
  4. Provide a beveled transition so the base flashing plies are not bent sharply Correct answer.

Explanation

A cant strip is a triangular or beveled wood or rigid insulation piece that creates a 45-degree angle at the roof-to-wall juncture. The base flashing plies can then be turned up smoothly instead of being creased at a sharp corner, where they would crack and admit water.