Commercial roof maintenance checklist: what to check, how often, and from where

HSE says roofs should be treated as fragile until a competent person confirms otherwise. Read HSE's fragile-surface guidance.

TJW Grab Hire's recorded metal roof was in good condition but ran with condensation. Read TJW Grab Hire.

The Midlands warehouse record identifies air leakage, condensation and drumming under rain as separate roof problems. Read the warehouse project.

01Start inside

First observations can start inside

Start inside, where you can see changes without stepping onto the roof. From safe accessible positions, look for water, stains, corrosion, new daylight through the roof, or a change in draughts and rain noise. Record where each one appears.

That gives the inspecting contractor a starting record. They still need to check the weathering details, hidden areas and material condition with appropriate access. Your observations help direct the inspection rather than replace it.

Add the date and conditions to each photograph. A wet-floor picture becomes much more useful when it shows the roof area above, the recent weather and what was happening inside. Give the contractor the details needed to trace the cause.

Project recordTJW Grab Hire, Bournemouth

02A starting schedule

A starting schedule to agree for the building

With a starting record in place, agree the routine checks. Spring and autumn, plus reviews after significant storms or a change in use, are a practical starting point. Adjust the frequency to your roof’s condition and system maintenance requirements.

03After a storm

After a storm

After a storm, record new water and visible changes from safe positions. Follow the site’s arrangements to keep people and operations clear of the affected area while you organise the appropriate inspection.

Tell the roofer when the water appeared and mark its location. If it arrived during rain, that helps them trace the path and find the weathering fault. Ask for the repair scope once the cause is established.

Keep the earlier records available. They can show whether the symptom is new or recurring and what work was previously completed. A repeated photograph with context can be more useful than an isolated statement that the roof still leaks.

04Rain entry or condensation

Drips: diagnose rain entry and condensation separately

Before calling every drip a leak, look at the pattern. Rain can enter through a fault, condensation can form underneath, and a roof can have both problems. Record the timing and spread so the assessment addresses each cause.

At TJW Grab Hire, Bournemouth, the recorded roof of about 505 m² box-profile steel roof was in good condition. The uninsulated roof ran with condensation onto vehicles and equipment; 50 mm of closed-cell was applied to its underside. The customer reported that the condensation was eliminated.

Correctly diagnosed and specified, closed-cell spray foam stops roof condensation. Zero call-backs for condensation. The depth is typically 25 mm or 50 mm closed-cell, depending on the roof make-up, confirmed before we spray, with risk analysis where needed.

Existing leaks go to a roofer first. HOLVEM is not a roofing contractor; spray foam is not waterproofing. Keep roofing repair and subsequent insulation separate in the maintenance plan. Read Roof leak or condensation.

05Fragile roofs and access

Fragile roofs and access

Before anyone goes above the roof, follow HSE’s approach: treat it as fragile until a competent person confirms otherwise. Fibre-cement sheets and rooflights need particular attention. Arrange the inspection and access around those risks.

Keep access planning separate from the checklist. Do not step onto the roof to inspect it or take photographs. Inspection, cleaning and repair need competent people, planned access and the controls for the actual work.

A treated fragile roof remains fragile. Keep the material information and access restrictions with your maintenance records so the next contractor plans the work from those facts, rather than the roof’s appearance.

Read HSE's guidance for the contractor and client responsibilities.

06Match the check to the roof

Match the check to the roof type

Metal roofs

For a metal roof, note corrosion, wetting and changes at laps or fixings you can see safely. Mark their locations. Existing rust needs assessment and, where required, repair; stopping condensation does not undo damage already present.

If water returns, ask for the diagnosis and proposed work in writing. A weathering repair and an underside condensation treatment do different jobs, so their objectives should be clear. Read Metal roof corrosion for that distinction.

Fibre-cement and asbestos-cement roofs

For asbestos or suspected asbestos, start with the building’s material records and competent advice. The dutyholder’s management arrangements guide how the inspection and work are planned.

Report changes from a safe position and arrange the appropriate contractor’s assessment. HOLVEM does not test for asbestos or replace roof sheets, and never removes asbestos sheets. If the roof is safe to keep, we encapsulate it; if not, removal is a job for asbestos removal professionals, licensed where HSE requires it. Read Fibre-cement and asbestos-cement roofs.

Flat roofs

For other roof systems, agree the inspection and maintenance requirements for that construction. Ground-level and interior observations can flag wetting and changes, but the inspector still needs to examine weather-facing details you cannot safely see.

If the same faults keep returning, use the maintenance history to review the bigger job. Have the condition and remaining work assessed before choosing a treatment. The project team needs to know what has already been tried.

07When it becomes refurbishment

When maintenance becomes refurbishment

That is when maintenance becomes a refurbishment decision. Recurring wetting, several unresolved faults or a change to the premises call for a wider assessment. Compare the finished results each proposal delivers, rather than keep treating separate symptoms.

The findings can point to local roofing repairs, an external system, underside insulation or another route. Ask what each proposal fixes and what remains to be done. HOLVEM is a building-performance specialist, not a roofing contractor.

Global House, Surbiton, records external work from above on about 1575 m² of pitched asbestos-cement roofs and an office roof: biocidal wash, 25 mm closed-cell roofing foam and an airless silicone finish as one continuous system.

Read Ageing commercial roofs: refurbish or replace to work through the wider decision. Then check the proposed programme and scope against the assessment of your own building.

08Keep a useful record

Keep a useful maintenance record

To make the record useful, give each observation a date, location and short description. Add weather, building use and photographs taken safely. Say whether the cause has been established or is still being investigated.

Follow that with the contractor’s findings, completed work, exclusions and follow-up actions. Keep separate problems open until each has been resolved. Finishing one leaking detail does not close a moisture problem elsewhere.

At the Midlands distribution warehouse, the corrugated metal roof leaked air, collected condensation and drummed under rain. Its specified 75 mm closed-cell treatment addressed those recorded problems. Keep the same link between symptom, objective and completed work in your own record.

If insulation or refurbishment is the next step, send us that history with your enquiry. It helps us understand the building before assessing the treatment. Start a project brief or Send photographs.

09Where to start

Three questions point to the first step.

Answer the three questions to identify the first step to discuss. The appropriate inspection or assessment then confirms what the roof needs.

11Questions, answered

Questions about commercial roof maintenance

How often should a commercial roof be inspected?

Start with spring and autumn checks, plus a review after significant storms. Adjust the routine to the roof’s condition, use and system maintenance requirements. Arrange a competent inspection for the areas you cannot see safely from inside.

What should be checked after a storm?

From safe positions, record new water, visible damage or debris and the affected area. Follow the site’s arrangements to keep people clear and organise the roofing inspection. Do not walk onto a fragile roof for photographs.

How can I tell condensation from a leak?

Note where and when the water appears, with the rain and internal conditions. That helps the assessment establish the cause. Repair existing leaks first; specify condensation treatment separately for the roof construction.

Who can go onto a fragile roof?

Access and work need competent planning and the controls required by HSE's guidance. Treat a roof as fragile until a competent person confirms otherwise. This checklist is for safe initial observations, not a roof-access method.

When should a roof be refurbished rather than maintained?

Arrange a wider condition assessment when faults recur, several areas are unresolved or the intended building use changes. Compare complete proposals against the problem and future use. A refurbishment system should not be chosen without the necessary repair, material and access information.