Warehouse Roof Defects: What to Do After Receiving a Survey Report

Receiving a roof defect report can feel overwhelming, particularly when it arrives alongside a dilapidations schedule, a lease renewal, or an acquisition. The list of defects can be long, the technical language unfamiliar, and the cost implications significant.

But a defect report is useful information. And acting on it early, with the right specialist contractor, means you can address problems in a planned and cost-controlled way rather than reacting to failures as they occur.

This guide covers the most common warehouse roof defects, what they mean, and how to efficiently move from a survey report to remedial works.

Why Roof Defects Are Common in Key Lease Events

At lease end, roofs are among the highest-value items in dilapidations schedules. Tenants who have allowed defects to develop may face significant financial exposure. And landlords reletting the building may need remedial works before the property becomes marketable.

During pre-acquisition surveys, a warehouse roof in poor condition can affect valuation, create requirements for price reduction or retention, or generate conditions that must be satisfied before exchange.

As part of planned maintenance programs, periodic surveys establish baseline conditions, track deterioration over time, and allow work to be budgeted in advance rather than triggered by an emergency.

Common Warehouse Roof Defects and What They Mean

Warehouse roofs are predominantly metal sheet systems with skylights, gutters, flashings, and surface penetrations.

As a result, the defects identified in condition reports follow predictable patterns, such as:

Cut-Edge Corrosion

Cut-edge corrosion occurs along the cut edges of steel roof sheets, where the factory-applied protective coating doesn’t cover the raw steel exposed during manufacture.

Moisture then attacks this steel, forming rust that spreads beneath the coating and lifts it from the substrate. Left untreated, this progresses to full perforation and water ingress.

Treatment involves cleaning and preparing the affected edges and applying a specialist coating system. Our roof coatings and cut-edge corrosion treatment service addresses this directly with systems designed for the profile and condition of the affected sheets.

Failed Rooflights

GRP or polycarbonate rooflights deteriorate with age and UV exposure. Beyond weather-related risk, delaminated rooflights are a potential fall-through hazard for anyone accessing the roof.

However, ACS Coatings’ skylight and gutter installation service covers rooflight replacement as part of broader refurbishment work.

Leaking Gutters

Box section steel gutters fail through corrosion, sealant breakdown, blockages, and thermal deformation. Specialist lining systems, such as HD Sharman Plygene, restore deteriorating gutters to full performance without full replacement.

If replacement is necessary, our skylight and gutter installation service provides a complete solution to this problem.

Damaged Flashings

Flashings seal junctions between roof sheets and adjacent elements. Heat cracks sealant over time, and flashings can lift, deform, or corrode. This can leave gaps through which water tracks behind the facade.

Correct identification of the failure mechanism and appropriate material selection are essential, and patch repairs with inappropriate products fail quickly.

Failed Roof Coatings

When previously applied protective coatings crack, peel, or delaminate, they lose waterproofing performance and can trap moisture. However, despite sounding serious, this alone is not a reason to replace the roof.

In most cases, the failed coating can be prepared, and a new system applied over the top. At ACS Coatings, our roof coatings service includes condition assessment and system specification as part of the process.

Loose Fixings

Fixings loosen through thermal cycling, corrosion, and washer wear. They allow water to enter through the fixing hole and reduce the wind uplift resistance of the sheet. Oversized replacement fixings with new neoprene washers restore weathertightness and uplift performance.

IF corrosion around fixing points is extensive, on-site repair and replacement of affected sections may be required.

Roof Penetrations and Leaks

Every penetration through a roof sheet is a potential leak point. Cracked collars, failed mastic seals at ventilation bases, and gaps are all common failure modes.

Our reactive maintenance solutions can address urgent penetration leaks while a planned program is developed.

What Warehouse Tenants Should Do After Receiving a Defect Report

Not all defects in a survey report are automatically your liability. So, your priority is establishing which defects you are responsible for under your lease. The scope of your repairing covenant, any schedule of condition, and when the defects developed also affect your exposure. So, take legal and surveying advice before committing to work.

Once liability is established, commission a specialist contractor to assess the roof and provide a quote. This gives you accurate figures for settlement negotiations and confirms whether the surveyor’s indicative costs are reasonable.

What Landlords Should Do After Receiving a Defect Report

The first question is whether remedial works are required before the building can be occupied or sold, or whether they can be managed as a known liability. Obtain a specialist contractor’s quotation to give you accurate cost information for financial planning.

Prioritise weather tightness and safety first, including failed rooflights, active leaks, and loose fixings. Then, plan longer-term works, such as coating renewal, as part of a structured maintenance program.

Our commercial waterproofing and roof coating services can be incorporated into a planned program that reduces future maintenance costs.