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Commercial and industrial flat roofs across Scotland

Commercial Flat Roofing Scotland

Survey-led repairs, refurbishment and replacement for commercial flat roofs.

Modern Roofing helps facilities managers, property teams and main contractors decide whether a flat roof needs a targeted repair, a planned refurbishment or complete replacement—based on the condition of the roof and the needs of the building below.

This page is for clients dealing with:

  • Active or recurring commercial flat-roof leaks
  • Ageing membranes, failed details or poor drainage
  • Repair, overlay, refurbishment or replacement decisions
  • Live buildings where access and disruption must be controlled
Established 2007 Modern systems, traditional values
2,000m² AG Barr Project Named factory refurbishment evidence
Survey-Led Decisions Repair, refurbish or replace on evidence
Scotland-Wide Delivery Central Belt and projects across Scotland

Commercial Flat Roofing Scotland from Modern Roofing

Commercial flat roofs need a different approach from domestic work. Roof areas are usually larger, access is more controlled, drainage and detailing carry greater consequences, and the building below may need to remain fully operational while works are carried out.

Modern Roofing carries out commercial flat-roof repairs, surveys, refurbishment and replacement work across Scotland, including Glasgow, Edinburgh, Lanarkshire and the wider Central Belt.

Before recommending a route, we consider the existing roof build-up, membrane condition, signs of moisture, drainage, rooflights, outlets, upstands, penetrations, access requirements and the operational needs of the client.

Solar-reflective white Sika membrane on a Glasgow commercial flat roof

Solar-reflective white Sika membrane on a Glasgow commercial roof, installed to support solar PV performance.

Direct answer

Modern Roofing provides commercial flat roofing in Scotland for industrial units, warehouses, offices, retail properties, public-sector buildings and commercial estates. The appropriate route may be a targeted repair, a compatible overlay, planned refurbishment or full replacement depending on the evidence found on the roof.

Commercial Flat-Roof Services

The right commercial flat-roof option depends on the existing build-up, the source and extent of any failure, the required service life, access constraints and how much disruption the building can tolerate.

Targeted flat-roof repairs

Investigation and compatible repairs for localised leaks, failed laps, damaged details, outlets, upstands, rooflights and penetrations.

Flat-roof surveys and investigation

Condition checks, leak investigation and practical evidence before deciding whether to repair, refurbish, overlay or replace.

Commercial roof refurbishment

Planned upgrade works for ageing roofs that need more than patch repairs but may remain suitable for an overlay or area-by-area refurbishment.

Full flat-roof replacement

Strip-off and replacement where the existing membrane, insulation, deck or wider roof condition is beyond a sensible repair or refurbishment route.

Single-ply membrane systems

Properly specified membrane build-ups for suitable new roofs, replacement projects and commercial refurbishment schemes.

Drainage, rooflights and details

Outlets, gutters, falls, parapets, rooflights, penetrations and perimeter details are considered as part of the whole-roof decision.

How We Select the Right Flat-Roof Route

The waterproofing product is only one part of the decision. The proposed route must suit the existing roof, the building, the details and the client’s operational requirements.

Existing build-up and condition

We consider the deck, vapour control, insulation, membrane, previous repairs and whether moisture or deterioration is isolated or widespread.

Drainage and difficult details

Outlets, falls, ponding, gutters, parapets, plant, rooflights and penetrations can determine whether a local repair, liquid detail or full membrane scheme is appropriate.

Access and live-site constraints

Safe access, internal protection, working hours, tenants, production, deliveries and weather exposure all affect how the work should be phased.

Why Commercial Flat Roofs Need a Survey-Led Approach

A commercial flat roof leak can affect stock, production, tenants, offices, plant rooms, electrics and customer areas. That is why Modern Roofing starts by looking for the cause instead of guessing from the internal stain.

Business disruption

Commercial roofs often sit above live operations, tenants, staff, machinery, offices or stock.

Drainage pressure

Flat roofs depend on outlets, falls and gutters. Small defects can become major issues during heavy rain.

Wrong-system risk

Putting the wrong material over a failing roof can hide the issue and cost more later.

Repair, Refurbish or Replace a Commercial Flat Roof?

The right decision depends on the roof condition, build-up, drainage, moisture, access, budget and the service life the client needs from the asset.

Commercial flat-roof repair, refurbishment and replacement decision guide
Option When it may make sense What Modern Roofing checks
Targeted flat-roof repair The defect is localised and the wider roof remains serviceable. Membrane type, failed details, laps, outlets, penetrations, surrounding condition and the likely route of water ingress.
Refurbishment or overlay The existing roof is suitable for a compatible upgrade and widespread strip-off may not be necessary. Build-up, moisture, deck condition, adhesion or fixing method, wind uplift, drainage, insulation, detailing and manufacturer suitability.
Full flat-roof replacement The membrane, insulation, deck or wider roof condition is beyond a sensible repair or overlay route. Strip-off risk, temporary weathering, internal protection, vapour control, insulation, drainage, programme and long-term cost.
Named project evidence

AG Barr Irn-Bru Factory — 2,000m² Flat-Roof Refurbishment

Modern Roofing acted as the main roofing contractor at the AG Barr Irn-Bru Factory, working across several commercial flat-roof areas that were not all in the same condition.

Roof appraisals and core samples were used to establish the build-up and select the appropriate route for each area rather than applying one generic specification across the whole site.

  • Failed areas stripped and rebuilt with a new vapour-control layer, insulation and waterproofing membrane.
  • Direct overlays where the existing felt roof was suitable to receive the new system.
  • Recovery-board refurbishment over suitable older membrane areas.
  • Approximately 2,000m² of completed commercial flat-roof refurbishment in 2026.

View the AG Barr project evidence

Why this matters to a commercial client

Some roof areas may need complete replacement while others can be refurbished or overlaid. A condition-led, area-by-area specification can avoid unnecessary strip-off without hiding defects that require a more substantial solution.

The decision should be based on the existing roof—not on selling the same system for every area.

“We would happily recommend Modern Roofing (Scotland) Ltd for any commercial or industrial roofing project.”

Robert, AG Barr

Discuss your commercial flat roof

Send the site location, approximate roof area, known roof system, leak history and any photographs or previous reports. Modern Roofing can then discuss the most appropriate next step.

AG Barr Irn-Bru Factory Flat-Roof Project Photos

These 12 approved project images show the roof investigation, core sampling, material loading, edge protection, installation progress and completed flat-roof areas at the AG Barr Irn-Bru Factory in Cumbernauld.

Core sample removed during the AG Barr factory flat-roof appraisal in Cumbernauld

Core sample taken to inspect the existing roof build-up before the refurbishment route was selected.

Second core sample measuring the existing AG Barr factory roof build-up

A second core sample helped confirm the roof construction and insulation condition across another area.

Roofing materials being loaded at the AG Barr Irn-Bru Factory in Cumbernauld

Material loading and logistics planned for the large operational factory site.

Temporary handrail coordinated with the AG Barr flat-roof refurbishment works

The handrail system was coordinated with recovery-board and membrane installation.

Waterproofing membrane refurbishment in progress at the AG Barr factory

Waterproofing membrane refurbishment in progress across one of the main roof areas.

Commercial flat-roof refurbishment during installation at the Cumbernauld factory

Installation work progressing across a separate commercial flat-roof area.

Progress across a large AG Barr factory flat-roof area

Progress across one of the larger roof areas during the phased refurbishment.

Completed waterproofing membrane roof area at the AG Barr Irn-Bru Factory

Completed waterproofing membrane across a large factory roof area.

Completed lower flat-roof area at the AG Barr factory in Cumbernauld

Completed lower roof area following the condition-led refurbishment works.

Finished lower roof waterproofing at the AG Barr Irn-Bru Factory

Finished waterproofing across another lower flat-roof area.

Completed AG Barr factory flat-roof refurbishment works in Cumbernauld

Completed flat-roof refurbishment works at the Cumbernauld factory.

Completed membrane roof on another AG Barr Irn-Bru Factory roof area

Completed membrane installation across another roof area at the AG Barr Irn-Bru Factory.

Other Commercial Flat-Roof Systems and Details

These Modern Roofing project images show different commercial flat-roof systems, including single-ply membrane, built-up felt and liquid-applied waterproofing, alongside repair and refurbishment details beyond the AG Barr factory project.

Commercial flat-roof refurbishment work in progress

Commercial flat-roof refurbishment work in progress.

Commercial flat-roof repair and waterproofing work

Commercial flat-roof repair and waterproofing work.

Single-ply membrane roofing work on a commercial building

Single-ply membrane work on a commercial roof.

Built-up felt roofing system on a commercial flat roof

Built-up felt roofing system on a commercial flat roof.

Sarnafil single-ply membrane roof with reinforced maintenance walkway

Sarnafil single-ply membrane with a reinforced maintenance walkway.

Liquid-applied waterproofing on a commercial roof detail

Liquid-applied waterproofing to a commercial roof detail.

What Happens After You Contact Modern Roofing?

The next step depends on the information available, the urgency of the problem and whether the roof needs a focused repair visit or a more detailed condition assessment.

1. Send the details

Provide the site address, building use, known roof type, leak history, approximate size and any useful photographs or reports.

2. Initial review

We review the information and discuss the problem, access, operational constraints and the most suitable form of inspection.

3. Compare the routes

Where evidence allows, the options are explained as repair, refurbishment, overlay or replacement rather than assuming one answer.

4. Scope the work

The proposed work can then be planned around roof condition, safety, weather, programme and the needs of the live building.

Need broader industrial roofing support?

Modern Roofing also provides industrial roof surveys, repairs, refurbishment, replacement, overcladding, gutter works and roof integrity testing across Scotland.

Explore Modern Roofing’s industrial roofing services

Commercial Flat Roofing Scotland FAQs

Do you carry out commercial flat-roof repairs?

Yes. Modern Roofing investigates and repairs suitable commercial flat-roof defects, including damaged membranes, failed details, outlets, rooflights, upstands and penetrations. The wider roof condition should also be considered where leaks are recurring.

Can a commercial flat roof be overlaid instead of replaced?

Sometimes. The existing build-up, moisture, deck condition, fixing or adhesion method, drainage, detailing and system compatibility must be checked before an overlay or refurbishment is recommended.

How do you decide between repair, refurbishment and replacement?

The decision is based on the location and extent of defects, the condition of the wider roof, moisture and insulation findings, drainage, expected service life, access, disruption and long-term cost.

Can work be planned around an occupied commercial building?

Yes, where the project conditions allow. Access, internal protection, working areas, deliveries, weather exposure, tenants and business operations should be considered when the programme and method are developed.

Which areas of Scotland do you cover?

Modern Roofing is based in Lanarkshire and carries out suitable commercial flat-roof work across Scotland, including Glasgow, Edinburgh, Lanarkshire and the wider Central Belt.

Send us your commercial flat-roof details

Tell us the building location, approximate roof size, known roof system and the problem you are experiencing. Photographs, previous reports and leak history can help us identify the most appropriate next step.