Flat Roofs – Should Defects Put You Off Buying a Property?

A flat roof often comes hand in hand with an extension – a popular solution for creating a larger living space in Victorian terraced properties – as well as porches and garages.

There is a wide range of flat roofs and roofing materials on the market, from the ubiquitous felt roofing to EPDM, a synthetic rubber membrane that is growing in popularity. They all have their pros and cons, but most need to be replaced after 10-15 years due to general wear and tear, depending on how well they’ve been installed and/or maintained over time.

Flat roof

If the property you are planning to buy features a flat roof area, special attention should be paid to its condition since any problems could impact on the condition of the corresponding interior area. Common problems include:

Flat roofs – Inferior workmanship and materials

A good roofer will take care to do a good job. However, all roofers are not equal and some will cut corners. Unfortunately, flat roofs can also be considered a DIY job and, as a result, the quality of the roof will be largely dependent on the skill of the enthusiastic amateur who installed it.

It’s worth noting, as well, that materials available to the DIY market are not necessarily the same quality available to professional roofers – that in itself can mean the roof may not be fit for purpose and will require replacing.

Flat roofs – Ponding

A flat roof properly constructed will never be completely flat, it should have a gradient of between 1:60 and 1:80. In the absence of an appropriate fall, or if it has been affected through structural movement, ponding may well occur. This is where water collects on the surface – either directly because of rainfall or through another water source e.g. a leaking pipe.

Staining and moss growth are tell-tale signs of ponding and long-term ponding will have a detrimental effect on the roofing material

Flat roof problems

Flat roof problems

Thermal movement stress

Whilst newer materials are far more durable, older flat-roofing materials are susceptible to degradation over time due to solar radiation. If the surface has not been sufficiently protected – by solar reflective paint or a layer of chippings, for instance – the material will suffer splitting and cracking at joints and corners.

Damage may be accelerated if the covering has been installed without adequate allowance for the anticipated movement of the underlying structure.

Flat Roofs – Blistering

This is caused when moisture is trapped between waterproofing layers. Needless to say, blistering left untreated can result in damage to the roof structure itself.

Condition of flashing

Flashing prevents water penetrating a junction between materials. Poor installation or damage over time can contribute with problems of leaking, which can then impact on the condition of the structure below the roof covering.

These problems aren’t necessarily astronomical to resolve – patch repairs may be sufficient. That said, whatever issue may be identified during inspection, a home-approved© building survey will provide clear information, determining how serious (or not) it is and an estimation of what the remedial costs will be.

Use our quick quote request form or simply call us today on 0800 980 3113 to arrange your home-approved© building survey.