GAF Roof System Design & Inspection 5

Question 1

In a GAF roofing system warranty context, what is the significance of 'wind speed rating' on shingle products?

Accepted Answer

It specifies the maximum sustained wind speed the shingle is warranted to resist when properly installed

Answer

It indicates the maximum installation temperature for the shingles

Answer

It measures the wind-driven rain resistance of the underlayment beneath the shingles

Answer

It determines the required nail length for the application

Question 2

What is 'decking deflection' and why is it a concern during a roof inspection?

Accepted Answer

The flex or sagging of roof sheathing between rafters, which can indicate structural problems or cause shingle cracking

Answer

The downward slope angle of the deck panels toward the eave

Answer

The thermal expansion of OSB sheathing in summer heat

Answer

The measurement of deck boards that are not perfectly level

Question 3

Which of the following best describes the 'exposure' of a roof shingle?

Accepted Answer

The portion of the shingle visible after the next course is installed above it

Answer

The total length of the shingle from top to bottom

Answer

The amount of overlap between adjacent shingle courses

Answer

The width of the nailing zone on the shingle

Question 4

During a post-storm roof inspection, you find lifted shingle tabs that have resealed. What is the primary concern with this scenario?

Accepted Answer

Lifted and resealed tabs may hide cracking, tearing, or broken sealant that reduces future wind resistance

Answer

The shingles are permanently weakened and the seals will fail again in future storms

Answer

Resealed shingles are stronger than before because the sealant has been redistributed

Answer

There is no concern — if the shingles resealed, the roof is performing as designed

Question 5

What is the purpose of providing a 1/8-inch gap between OSB or plywood roof deck panels during installation?

Accepted Answer

To accommodate thermal and moisture expansion of the panels and prevent buckling

Answer

To allow for drainage of any moisture that gets beneath the shingles

Answer

To create a ventilation channel between the deck and the shingles

Answer

To reduce the overall dead load of the roof deck assembly

Question 6

When designing a roof system over an open-plan interior with no attic space, which ventilation strategy is most appropriate?

Accepted Answer

An unvented (hot roof) assembly with continuous rigid insulation meeting code R-value requirements

Answer

Standard ridge and soffit ventilation is still required

Answer

Installing power attic fans to compensate for the lack of attic space

Answer

Reducing the insulation thickness to allow some heat to escape through the deck

Question 7

What does the term 'counterflashing' refer to in roof system design?

Accepted Answer

Flashing embedded in a mortar joint or reglet that overlaps base flashing to complete the seal at a wall junction

Answer

A second layer of felt underlayment installed over the first layer

Answer

The flashing installed on the opposite side of a valley from the primary flashing

Answer

Reflective coating applied over metal flashing to reduce heat absorption