403A roofing, siding, windows and doors practice questions.

Five free practice questions on roofing, siding, windows and doors: block E of the Red Seal 403A Carpenter exam, about 14 of its 100 questions. They are in the exam's format: four options, one correct answer. Answer each one before opening the explanation. No account, no email.

01The questions

1. Procedural · Installs exterior doors

   You are installing a pre-hung exterior door unit. The opening is prepared and the sill pan is in place. Which jamb do you plumb and fasten first?

   1. The hinge-side jamb, checked plumb in both directions
   2. Either side; the order does not matter on a pre-hung unit
   3. The head jamb, so the top reveal is even
   4. The latch-side jamb, so the strike is located correctly
   Show the answer

   A. Correct. The hinge jamb carries the door, so it is plumbed and shimmed first, in the plane of the wall and across it. The door is then closed and the latch jamb is shimmed to give an even 3 mm (1/8 in.) reveal all round. The head is checked level last.

   Why not the others

   B. The order matters. A pre-hung door still has a hinge jamb that sets the door's position; plumbing it first is the only way to get an even reveal without repeated adjustment.

   C. The head has no load and is checked last. Fixing it first can lock in a racked frame if the sill is not level.

   D. The latch jamb is positioned relative to the hung door, not the other way round. Fixing it first means the hinge jamb is forced to fit whatever reveal is left.

2. Procedural · Installs exterior wall components

   Western red cedar bevel siding is being installed and will be left to weather naturally. Which fastener is the right choice?

   1. Bright common nails
   2. Stainless steel or hot-dip galvanized ring-shank siding nails
   3. Electro-galvanized siding nails
   4. Coated deck screws driven below the surface and filled
   Show the answer

   B. Correct. Cedar and redwood contain tannins that react with iron. Stainless steel (the best choice on wood that will weather unfinished) or heavy hot-dip galvanized nails resist it. Ring shanks hold in the strapping and the slim head sits flush without crushing the wood.

   Why not the others

   A. Bright steel rusts at once in an exterior wall and streaks the cedar. It is never used for siding.

   C. Electro-galvanizing is a thin coating. Cedar's natural extractives attack it and it leaves black streaks and rust spots on unfinished wood within a few years.

   D. Screws are harder to drive flush without splitting thin bevel siding, most coatings also react with cedar, and countersinking and filling a siding job is not trade practice.

3. Procedural · Installs roofing components

   An open (exposed metal) valley is being formed on an asphalt-shingle roof. What is the minimum width of the sheet-metal valley flashing, and how is it fastened?

   1. 600 mm (24 in.) wide, fastened at the outer edges only
   2. 450 mm (18 in.) wide, face-nailed along both edges
   3. 300 mm (12 in.) wide, nailed through the centre
   4. 900 mm (36 in.) wide, fully adhered with roofing cement
   Show the answer

   A. Correct. NBC 9.26 requires sheet-metal valley flashing to be at least 600 mm wide, centred in the valley, with head laps of at least 150 mm. It is held with clips or nails at the extreme edges only, so there are no fasteners in the water path, and the shingles are cut back to leave the centre exposed.

   Why not the others

   B. 450 mm is the width of a narrow valley liner in some manufacturer details, but the NBC minimum for sheet-metal valley flashing is 600 mm, and face nails along the edges are avoided.

   C. 300 mm is too narrow for the water volume a valley carries, and nails down the centre put holes in the wettest part of the roof.

   D. 900 mm is wider than required and fully bedding metal in cement prevents it moving with temperature, causing it to buckle.

4. Procedural · Installs exterior windows

   A 1 800 mm (6 ft) wide mulled window unit (two windows joined with a vertical mullion) is being shimmed in its opening. Where should shims be placed under the sill?

   1. Under each side jamb and directly under the mullion
   2. Continuously along the full width of the sill
   3. Only at the head, so the unit hangs straight from the header
   4. One shim pack in the centre only, under the mullion
   Show the answer

   A. Correct. Shims go under the sill at every vertical load line: both jambs and the mullion joining the two units. This keeps the sill straight so the sashes operate. No shims go between the head and the header, which would transfer building load onto the frame.

   Why not the others

   B. A continuous shim is impossible to adjust for level and blocks drainage across the sill pan. Shims are placed at the load points only.

   C. Windows are supported from below, never hung from the header. Shims at the head can load the frame if the header deflects and will bind the sash.

   D. A single central shim lets the unit rock and the ends droop. Each jamb line needs support as well as the mullion.

5. Procedural · Installs exterior wall coverings

   Fibre-cement lap siding is being installed with butt joints between boards. How are the butt joints treated?

   1. Boards are mitred at every joint to hide the end grain
   2. Boards are lapped end over end by 50 mm (2 in.)
   3. Boards butted tight and the joint caulked on the face with paintable sealant
   4. Boards in moderate contact with a flashing tab behind each joint, joints staggered
   Show the answer

   D. Correct. The manufacturer's standard detail is a 150 mm (6 in.) wide piece of flashing (metal, membrane, or a joint tab) behind every butt joint so water entering the joint is carried out onto the course below. Joints are staggered so they do not line up vertically. Boards are blind-nailed about 25 mm (1 in.) from the top edge into framing or strapping, with a minimum 32 mm (1-1/4 in.) headlap.

   Why not the others

   A. Fibre cement is not mitred at butt joints; the material is too brittle for thin mitres and the joint still needs flashing behind it.

   B. Lapping the ends makes a bump and a water trap. Butt joints with flashing behind are the correct detail.

   C. Face caulking fibre cement joints is unreliable: the joint moves slightly, the caulk fails and the wall relies on a single, failed seal.

02Answer key

03What block E covers

This block covers the building envelope and the openings in it. It includes setting exterior door and window frames, flashing rough openings, door handing, hinges and hardware, eave protection, underlayment, drip edge, step and valley flashing, attic ventilation, asphalt, wood and metal roofing, rain-screen walls, housewrap, and vinyl, wood, fibre-cement, stucco and brick veneer cladding.

The Red Seal Occupational Standard names this block “Performs exterior finishing”. It carries 14% of the exam, about 14 of the 100 questions, split across three tasks. The share column is each task's weight within the block, as the standard publishes it.

04What the questions turn on

Flash from the bottom up

Window flashing starts with the sill pan, then the jambs, then the head, with the housewrap above folded down over the head flashing. Leave the sill flange unsealed so water that reaches the pan can drain out.

Plumb the hinge jamb first

The hinge jamb carries the door, so plumb it both ways and shim it first, then shim the latch jamb for an even reveal. Shims and fasteners go at the hinges and strike. A door that swings on its own has a leaning hinge jamb.

Eave protection and attic vents

Eave protection runs at least 900 mm up the slope and to 300 mm inside the inner wall face, whichever is farther. On roofs steeper than 1:6, attic vents total 1/300 of the insulated ceiling, at least a quarter high and a quarter low.

Let vinyl siding move

Nail vinyl siding in the centre of the slot with the head about 1 mm off the panel. Leave about 6 mm at panel ends in warm weather and about 10 mm below 0 °C, or the panels buckle in summer heat.

05The other blocks

The 403A exam has seven blocks. Each has its own page of free questions:

The 403A Carpenter practice exam page describes the full question bank. How these questions are written and checked: how our questions are made. Found a mistake? Tell us and we will fix it.