The common difference measurement is used to determine the _____.

The common difference measurement is used to determine the _____.
 
  a. spacing between common rafters
  b. lengths of lookouts
  c. lengths of gable studs
  d. spacing of collar ties

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[Ques. 2] When erecting a gable roof, which portion of the rafter is nailed to the ridgeboard?
 
  a. the birds mouth
  b. the plumb cut
  c. the tail cut
  d. the seat cut

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[Ques. 3] When collar ties are needed to brace rafters, they are installed on _____.
 
  a. every rafter
  b. every other rafter
  c. every third rafter
  d. every fourth rafter

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[Ques. 4] Local fire codes must be consulted when framing an opening around a chimney to establish _____.
 
  a. correct pitch
  b. rafter spacing
  c. proper clearance
  d. insulation requirements

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[Ques. 5] When making the birds mouth cut, its depth should not exceed _____.
 
  a. one-third the rafters width
  b. the rafters thickness
  c. one-fourth the rafters thickness
  d. the depth of the top plate