Roof Sailing Roof Flashing and Waterproofing 2

Question 1

What sealant should NOT be used as the sole waterproofing for roof pipe boot flashings?

Accepted Answer

Roofing cement caulk only

Answer

Roofing cement or caulk alone will crack and fail within a few years when used as the sole seal around pipe penetrations; proper pipe boots with flexible collars are required for long-term waterproofing.

Question 2

What is the recommended minimum distance that base flashing should extend up a chimney face?

Accepted Answer

6 inches

Answer

Base flashing at chimney faces should extend at least 6 inches up the face of the chimney to provide adequate protection against wind-driven rain, per most building code requirements.

Question 3

When must a two-piece (two-part) pipe boot be used instead of a one-piece boot?

Accepted Answer

When the pipe is already installed and cannot be removed

Answer

A two-piece (split) pipe boot is used when the pipe or stack is already permanently installed and cannot have a one-piece boot slid over it; the split boot wraps around the existing pipe.

Question 4

What is the correct overlap for W-metal valley flashing sections when multiple pieces are needed?

Accepted Answer

6 inches

Answer

W-metal valley sections must overlap by a minimum of 6 inches, with the upper piece lapping over the lower piece to ensure water is directed outward rather than into the joint.

Question 5

What material is NOT compatible with copper flashing and can cause rapid corrosion?

Accepted Answer

Pressure-treated lumber with ACQ (copper-based preservative)

Answer

ACQ (Alkaline Copper Quaternary) pressure-treated lumber contains high levels of copper, which creates a galvanic reaction with additional copper flashing — zinc or stainless fasteners and separating barriers must be used.

Roof Sailing Practice Test

Roof Sailing Practice Test

Roof Sailing Roof Flashing and Waterproofing 2