Modified Bitumen Roofing

What This Service Involves

Modified bitumen takes the proven waterproofing of asphalt and enhances it with SBS or APP polymers that keep the membrane flexible in our cool, damp winters. We apply it in reinforced rolls, either torch-applied, cold-adhered, or with self-adhering sheets depending on the building and surrounding fire exposure. The granulated cap sheet resists UV and provides a walkable, durable surface for the rooftop equipment servicing common on Northwest commercial buildings. Multiple layers and heat-fused or bonded seams give this system the redundancy and reliability that steady regional rainfall requires.

Benefits

Polymer modifiers keep the membrane flexible in cool weather; Multi-ply construction adds redundant leak protection; Granulated cap resists UV and handles foot traffic; Multiple application methods suit different buildings safely; Strong seams stand up to sustained Northwest rainfall

Our Process

1) Prepare the deck and set insulation with proper drainage; 2) Install the base ply and bond it to the substrate; 3) Apply the modified bitumen cap sheet by torch, cold adhesive, or self-adhesion; 4) Seal all seams, flashings, and penetrations for a watertight finish

What Affects the Cost

Number of plies and the reinforcement grade chosen; Application method, whether torch, cold-applied, or self-adhered; Roof size and the complexity of edges and penetrations; Granule color and any reflective surfacing upgrade; Existing roof removal and deck repairs required

Best Time of Year

Dry summer conditions allow adhesives and torch-applied laps to bond cleanly, so we schedule mod-bit work between June and September.