Inspection, Defects, Repairs, and Code Compliance
Inspection, Defects, Repairs, and Code Compliance
This domain tests how to inspect a modified bitumen roof, classify defects, make durable repairs, and verify code requirements. Expect field-practical questions on laps, blisters, wrinkles, ponding, and repair sequencing.
Core rules
- Inspect substrate, attachment, lap width, bleed-out, seam adhesion, flashing heights, counterflashing, drains, and terminations. Record defects with location and extent.
- Common defects: fishmouths and voids at laps from insufficient heat or contamination; blisters from trapped moisture or air; wrinkles from poor rolling; ridging; ponding from inadequate slope; open seams from cold adhesive or dirty laps.
- Moisture surveys and core cuts may be needed before repairs. Do not cap a wet blister; cut, dry, and patch.
- Repairs use compatible membrane and adhesive. Cut back to sound material, clean and prime, extend patches beyond the defect, stagger laps, and roll or heat according to the system.
- Code compliance includes positive drainage, fire classification of the assembly, wind-uplift approval, flashing height, and energy-code requirements where applicable.
Worked example
A blister is 12 in across and feels soft. Do not apply a patch over it. Cut an opening, dry the area, remove trapped moisture, and install a patch that extends well beyond the cut with proper laps. If moisture is widespread, replace the affected area; a surface patch will trap water and the blister will return.
Traps
Patching wet insulation; trimming a blister without drying; extending a patch less than the required lap; using incompatible adhesive; ignoring ponding; assuming a fire-rated label covers the whole assembly.