Roofing
A commercial roof is a complete system—not simply the visible membrane. Its performance depends on the membrane, insulation, drainage, perimeter metal, penetrations, flashings, expansion joints, and connections to adjacent walls and rooftop equipment.
GD Osman provides commercial roofing services for new construction, replacement, restoration, maintenance, and repair projects. Our team works with building owners and project partners to assess roof conditions, identify active and potential failure points, and develop a practical scope based on the building's needs, operating requirements, and long-term plans.
Capabilities include:
- Membrane roofing systems
- Roof replacement and restoration
- Roof repairs and leak investigation
- Preventive maintenance programs
- Roof insulation and thermal upgrades
- Roof panels and metal roofing components
- Flashing, coping, edge metal, and penetration details
- Drainage improvements involving drains, scuppers, and related details
- Coordination around rooftop mechanical equipment and occupied spaces
We focus on accurate diagnosis and careful detailing because many roof leaks originate at transitions, penetrations, perimeters, or adjoining wall systems—not in the open field of the roof. By looking at the roof as part of the larger building envelope, GD Osman can recommend solutions that address both immediate problems and long-term performance.
Siding
Commercial siding and wall cladding have to shed water, accommodate movement, and meet the building at every opening. Failed joints, open transitions, and mismatched replacements are common paths for moisture and air leakage.
GD Osman repairs and replaces commercial siding as part of a coordinated envelope scope. We look at how the wall meets the roof, windows, and waterproofing so the new or restored cladding does not leave the same gaps behind.
Typical siding work may include:
- Commercial wall cladding repair and replacement
- Panel, metal, and composite siding systems
- Substrate repair at deteriorated wall areas
- Transitions at roofs, parapets, and grade
- Window, door, and penetration closures
- Sealant, flashing, and joint detailing
- Coordination with masonry and sheet-metal work
The goal is a continuous exterior wall — not a patch that looks finished from the street and still leaks at the edges.
Windows
Windows are openings in the envelope. Their performance depends as much on the perimeter — flashing, sealant, sills, and adjacent cladding — as on the unit itself.
GD Osman provides commercial window replacement and related envelope detailing. We coordinate new or restored windows with siding, masonry, and waterproofing so the opening stays weathertight and the surrounding wall remains intact.
Services may include:
- Commercial window replacement
- Perimeter flashing and sealant replacement
- Sill, head, and jamb detailing
- Coordination with siding and masonry restorations
- Air- and water-leak investigation at openings
- Repairs at storefront and punched-opening conditions
Replacing a window without rebuilding the details around it often repeats the same leak. We treat the opening as part of the whole building.
Waterproofing
Water intrusion can damage structural components, interior finishes, equipment, inventory, and tenant spaces. It can also create recurring operational problems when the true entry point is not correctly identified. Because water often travels within an assembly before becoming visible, effective waterproofing begins with understanding how the entire building manages water.
GD Osman provides waterproofing solutions for commercial structures above and below grade. We evaluate joints, penetrations, transitions, cracks, walls, decks, foundations, and adjoining assemblies to determine where moisture is entering and how the condition should be addressed.
Services may include:
- Below-grade foundation waterproofing
- Exterior wall and building-envelope waterproofing
- Plaza, terrace, balcony, and deck systems
- Joint, crack, and penetration treatment
- Sealant removal and replacement
- Flashing and transition repairs
- Water-intrusion investigation and corrective work
- Sheet-applied and fluid-applied waterproofing systems
- Repairs at roof-to-wall and wall-to-foundation transitions
- Traffic-bearing coatings on parking decks and ramps
Our objective is to create continuity across the waterproofing system. Even high-performing materials can fail when terminations, transitions, penetrations, or connections to adjacent systems are overlooked. GD Osman emphasizes these critical details to help keep commercial buildings dry and operational.
Sheet Metal
Architectural sheet metal protects some of the most vulnerable areas of a building. Copings, counterflashings, edge metal, gutters, downspouts, panels, and custom transitions must direct water away from the structure while accommodating movement and weather exposure.
GD Osman provides commercial sheet-metal fabrication, installation, repair, and replacement as part of roofing and building-envelope projects. Our team develops practical details for conditions that standard components cannot adequately address and coordinates sheet-metal work with adjacent roofing, masonry, waterproofing, and wall systems.
Services may include:
- Copings and wall caps
- Counterflashing and through-wall flashing
- Roof-edge and perimeter metal
- Gutters, leaders, and downspouts
- Scuppers, conductor heads, and drainage components
- Metal roof and wall panels
- Equipment curbs, penetration flashings, and transitions
- Custom-fabricated metal details
- Repair and replacement of deteriorated or improperly installed components
Well-executed sheet-metal work improves both performance and appearance. More importantly, it closes gaps between building systems and helps water move safely away from the structure.
Stone and Masonry
Stone, brick, block, mortar, and related façade components are durable, but they are not maintenance-free. Exposure, building movement, freeze-thaw cycles, moisture, corrosion, and aging sealants can create cracks, open joints, displaced units, staining, and water-entry paths.
GD Osman performs commercial stone and masonry repair and restoration with attention to both structural function and finished appearance. We assess the visible damage as well as the conditions that may be causing it, including failed flashing, open joints, poor drainage, movement, and corrosion of embedded metal components.
Services may include:
- Brick, block, and stone repair
- Repointing and mortar-joint restoration
- Removal and replacement of damaged masonry units
- Crack repair and localized reconstruction
- Parapet, coping, and façade repairs
- Through-wall flashing and related waterproofing details
- Sealant replacement at masonry joints and transitions
- Coordination with lintels, shelf angles, and adjacent components
- Cleaning and restoration associated with repair work
Our approach is to preserve serviceable materials whenever practical while repairing failed areas with compatible systems and sound construction details. This helps restore the enclosure, improve appearance, and reduce future water-related deterioration.
