Flat roofs are common on many types of commercial premises. They can be a cost-effective construction method and, when designed, installed and maintained correctly, the coverings can give 10-20 years of reliable service.
However, flat roof coverings suffer from weathering and UV degradation over time which lead them to become perished and brittle, and they gradually deteriorate. They sometimes get damaged, and if they’re neglected due to blocked drainage routes or uncleared vegetation their condition will deteriorate more rapidly – perhaps catastrophically.
They key to avoiding premature, and often disruptive failure, is regular inspection and assessment to identify any potential issues and then instigate preventative repairs in order to maintain their lifespan.
Risks
Whether freeholder or lessee, an old or poorly maintained flat roof can represent a significant financial risk. It’s not just the cost of repairing the roof; the secondary damage from water ingress to the building fabric and your business equipment can run to tens of thousands of pounds and may interrupt trading.
The nature and location of many flat roofs means that signs of deterioration aren’t always obvious – and certainly not from the ground, and out-of-sight often means out-of-mind.
When conducting building surveys when there’s no easy, safe or cost-effective access to the roof, we commonly use a drone to capture a high-definition photographic record of the condition, and an interrogation of the data will highlight whether there are any signs of water pooling, poor drainage, deteriorating roofing materials or flashings, or any gaps that might be developing between joints and seams – it’s usually pretty clear when the landlord or previous tenant hasn’t looked after a flat roof diligently.
Options
Calculating whether it’s best to carry out isolated repairs to areas of the roof or go for a complete replacement needs experience and careful judgement.
The answer will depend on the age, size, material and overall condition of the roof. It might also depend on your cashflow and current finances.
In some instances a modern overlay system might be appropriate, as opposed to complete replacement, particularly as replacement of over 25% of the roofs area will require Building Regulations approval which often requires improvements to both insulation and ventilation to ensure compliance. More extensive building work is often required as result in order to raise parapets or alter drainage.
Whatever the circumstances it helps to have a detailed condition report which often includes a degree of intrusive investigation (a core sample) and an expert opinion on options, costs and risks. This knowledge can also be helpful when you negotiate a purchase or perhaps lease terms.
If you opt for replacement, there are a number choices from traditional built-up roofing with bituminous felt, modern PVC single ply systems, EDPM rubber, glass reinforced plastic (GRP – or fiberglass) – among others.
Thermal Performance
Energy efficiency is another consideration in weighing up what to do about a deteriorating flat roof. An old roof is unlikely to meet modern energy efficiency standards and replacing it with a modern thermally insulated system will help cut your energy bills and CO2 emissions.
If you are considering purchasing or leasing a commercial premises with a flat roof, it always pays to consult an expert commercial building surveyor. Hicks Baker can also give you an independent opinion on your options for flat roofs that may be nearing end-of-life on premises you already occupy.
Contact Lloyd Rockall l.rockall@hicksbaker.co.uk, 0118 467 1712