Why Roofing Manufacturers Inspect Commercial Roof Installations

On many commercial roofing projects, the roofing manufacturer can play a greater role than simply supplying the materials.

Depending on the manufacturer, roofing system and warranty arrangements, this can include technical input during the specification stage and inspections while the roofing system is being installed.

For building owners, managing agents, housing providers and public-sector organisations, manufacturer involvement can provide an additional level of oversight on projects where a complete manufacturer-backed roofing system is being installed.

However, manufacturer inspection processes vary, so it is important to understand what they involve - and what they don't.

Why Are Roofing Manufacturers Involved in Commercial Projects?

Commercial roofing manufacturers develop systems rather than simply individual waterproofing products.

A complete roof build-up may include:

• Vapour control layers

• Insulation

• Adhesives and primers

• Waterproofing membranes

• Reinforcement

• Detailing products

• Accessories

These components are designed to work together as part of the overall roof construction.

Where a manufacturer-backed system is specified, the manufacturer may provide technical support to help ensure the proposed construction is appropriate for the project.

PRC works with a range of established roofing manufacturers across commercial, public-sector and multi-residential roofing projects.

Why Might a Manufacturer Inspect the Installation?

Where manufacturer inspections form part of a project, one purpose is to review the installation of the specified roofing system.

This can include looking at whether relevant elements of the works are being installed in accordance with the manufacturer's specification and requirements.

The exact inspection process varies considerably between manufacturers and roofing systems.

It should therefore not be assumed that every commercial roof receives the same number or type of manufacturer inspections.

When Do Manufacturer Inspections Take Place?

There isn't one standard inspection programme that applies to every roofing project.

Depending on the manufacturer and project, inspections may take place at different stages of the works.

This could include visits while the installation is progressing and/or towards completion.

Larger projects may also be completed in phases, which can influence how manufacturer involvement is organised.

The inspection requirements should be established for the particular roofing system and warranty arrangement being proposed.

What Might a Manufacturer Look At?

The exact scope varies, but inspections may consider aspects of the installed roofing system in relation to the manufacturer's requirements.

This can include areas such as:

• General installation of the waterproofing system

• Insulation and roof build-up where applicable

• Upstands

• Roof edges

• Outlets

• Rooflights

• Penetrations

• Detailing around plant and services

• Interfaces between different parts of the roof

These details can be particularly important because commercial roofs rarely consist of one uninterrupted waterproofed area.

A roof may contain dozens of penetrations, outlets, rooflights and changes in level that all need to integrate with the specified system.

Why Is Detailing So Important?

Large open areas of a commercial roof can often be relatively straightforward compared with the junctions around them.

Waterproofing may need to transition around pipes, ducts, plant bases, parapets, rooflights and drainage outlets.

Each creates an interruption in the main roof area.

Correct detailing is therefore an important part of the complete installation rather than something that should be considered separately at the end.

This is also why manufacturer specifications can contain particular details for common roof interfaces.

Does a Manufacturer Inspection Replace the Roofing Contractor's Quality Control?

No.

Manufacturer involvement doesn't remove the roofing contractor's responsibility for managing and installing the works appropriately.

The contractor still needs to manage the installation, workmanship and site activities throughout the project.

Manufacturer inspections can form an additional part of the process where applicable, but they shouldn't be treated as a substitute for the contractor's own quality-control procedures.

What Happens if an Issue Is Identified?

If something is identified during an inspection that doesn't meet the relevant manufacturer's requirements, it may need to be addressed.

Exactly how this is managed depends on the issue, manufacturer and stage of the project.

Identifying something while works are still progressing can be particularly useful because the relevant area may be more accessible than it would be once the entire roof build-up has been completed.

It also reinforces why communication between the roofing contractor, manufacturer and project team can be important on larger refurbishment schemes.

How Do Inspections Relate to Roofing Warranties?

Manufacturer inspections and warranties can be connected, depending on the system and warranty arrangement.

Certain manufacturer-backed warranties may have specific requirements regarding specification, installation, inspections and completion.

However, an inspection itself should not simply be interpreted as an automatic guarantee that every aspect of the roof is covered.

Clients need to understand the actual warranty documentation and applicable conditions.

As we explain in our guide to commercial roofing warranties, different warranties can relate to different elements of a roofing project.

Why Does the Original Specification Matter?

Manufacturer involvement can begin before anyone starts installing the roof.

On some projects, the manufacturer may provide technical input into the proposed system or specification.

Once that system has been agreed, the installation needs to reflect the relevant project requirements.

Substituting components or changing details during construction without considering the wider roofing system can potentially create problems.

This is particularly important where waterproofing, insulation, vapour control layers and accessories have been designed to operate together.

What Happens if the Roof Changes Once Work Begins?

Roof refurbishment can reveal conditions that weren't fully visible beforehand.

Once existing coverings are removed, contractors may discover wet insulation, deterioration or differences between the assumed and actual roof construction.

We have previously looked at why roofing projects often uncover additional problems once work begins.

Where discoveries affect the proposed roofing system, the contractor, project team and manufacturer may need to consider whether the original detail or specification remains appropriate.

The important point is not to assume that an agreed specification should simply be installed regardless of what is discovered underneath the existing roof.

Why Are Approved Contractor Schemes Relevant?

Some roofing manufacturers operate approved, registered or authorised contractor schemes.

The terminology and requirements differ between manufacturers.

These schemes can help manufacturers control who installs particular systems and may form part of the arrangements for certain manufacturer-backed projects or warranties.

For clients, this is another reason to look beyond simply selecting a roofing product.

The proposed manufacturer, system, specification and contractor can all form part of the overall roofing solution.

Manufacturer Involvement Can Be Particularly Useful on Complex Roofs

Commercial roofs can become technically complicated.

A large roof may contain:

• Numerous rooflights

• Plant and equipment

• Multiple drainage outlets

• Different roof levels

• Large numbers of penetrations

• Changes in substrate

• Existing waterproofing systems

• Complicated perimeter details

The appropriate solution may therefore involve much more than choosing a waterproofing membrane.

Manufacturer technical support can be useful where the proposed system needs to accommodate complicated existing conditions.

Our existing article on why rooftop plant equipment creates roofing challenges looks at one common source of complexity on commercial roofs.

What About Large or Phased Roofing Projects?

Large commercial roofing schemes may be completed over an extended period.

This can include housing estates, schools, commercial buildings and other properties containing substantial roof areas.

The roofing works may need to be divided into phases to maintain access, manage weather exposure or allow parts of the building to remain operational.

Where manufacturer inspections form part of the project, the inspection arrangements may need to work alongside that programme.

This is particularly relevant where sections of roofing are completed at different stages.

Are Manufacturer Inspections Only for New Roofs?

Manufacturer involvement isn't necessarily limited to completely new buildings.

Many manufacturer-backed commercial roofing systems are installed as part of refurbishment projects.

In these situations, the new roofing system needs to interact with an existing building and potentially an existing roof construction.

This can make technical assessment particularly important because the new system needs to be appropriate for the conditions found on the project.

Why Building Owners Should Understand the Inspection Process

Where manufacturer involvement forms part of a proposed commercial roofing project, clients should understand what that actually means.

Useful questions can include:

• Will the manufacturer provide technical input?

• Does the project include manufacturer inspections?

• At what stages might inspections take place?

• Are inspections required for the proposed warranty?

• What happens if an issue is identified?

• What documentation is provided at completion?

The answers will vary depending on the manufacturer and system.

Understanding the process at the beginning of the project can prevent assumptions later.

Manufacturer Inspections Are One Part of the Wider Roofing Project

A manufacturer inspection shouldn't be viewed in isolation.

Successful commercial roofing projects still depend on appropriate specification, competent installation, good project management and suitable detailing.

Manufacturer involvement can support that process where applicable.

This is particularly valuable when the waterproofing system forms part of a complete manufacturer-backed roof build-up rather than being treated as an individual product.

Commercial Roofing Manufacturer Systems

Premier Roofing & Construction installs commercial roofing systems from established manufacturers including Bauder, Garland, Langley, Alumasc, Soprema, Proteus, Polyroof, Nimbus, Triflex and WestWood.

We undertake commercial roof refurbishment and replacement projects across London, Essex, Kent and the wider South East.

Depending on the roofing system and project requirements, manufacturer technical support, inspections and warranty arrangements may form part of the proposed works.