Please Note: This Article is 7 years old. This increases the likelihood that some or all of it's content is now outdated.

Whether you own a home or building with an existing flat roof or are considering an extension which will feature one, it’s useful to understand some of the unique aspects this sort of roofing presents.

Undoubtedly, the most notorious feature of poorly constructed flat roofs of the past has been their tendency to leak. Getting your flat roof drainage right is an important aspect of installing and maintaining one.

As a property owner, you may not want to become a roofing expert, that’s what you employ the professionals for! At the same time, having a little information and knowledge will help you when you’re assessing the competence of anyone you’re considering employing.

Everything You Need to Know in Non-Technical Language

The National Federation of Roofing Contractors (NFRC) has recently revised (2015) its publication ‘The Householder’s Guide to Flat Roofing’.

In this free guide you’ll find all the information required to understand the concepts behind flat roof construction and information about the regular checks and maintenance required to keep them in good condition. The guide has been written in plain English so that the information is accessible to anyone.

Topics covered in the guide:

Introduction: Bitumen membranes are still the most often used construction material. Modern roofing is of a much higher quality that past methods, you may hear the term reinforced bitumen membranes.

Basic design: The roof decking used to support waterproof layers is generally of timer instruction.

Most roofs will be insulated to comply with building regulations though flat roofing above garages does not need to be. Flat roofs must also be designed to meet the fire prevention aspects of UK building regulations.

Warm and cold roofs: In warm roofs the insulation is above the roof deck, in cold roofs it’s below.

‘Cold roofs’ are more prone to condensation, which can shorten their useful lifespan. Cold roofs are possible within UK building regulations but warm is preferred. The Scottish building regulations do not endorse cold roofs.

Essentials for a successful flat roof: Flat roofs must be be built to withstand rain, snow, sun, frost, condensation, wind and fire. Their construction should also take account of anticipated foot traffic.

‘Flat’ roofs are not flat!

They’re much less sloped than conventional roofs but in fact a design fall of 1 in 40 to 1 in 60 is advised in order to assist flat roof drainage. Generally speaking conventional gutters are preferred to internal outlets.

Maintenance: Inspection should be carried out twice a year, usually in March and November. At least one inspection should be conducted immediately after rain to assess how well the roof is draining. Some inspection can be completed by a householder, other work should be completed by a professional contractor.

In the event of problems the practicality of repairs needs to be assessed. If the roof is still under guarantee the original contractor should be consulted before repairs are attempted.

Factors to be taken into consideration include:

  • The age and overall condition of the roof
  • Desire to improve insulation

Factors that indicate that re­roofing is the preferred solution include:

  • Roof sagging between joists
  • Split or punctured membranes
  • Refurbishment of a flat roof is likely to be notifiable to the local authority building control department


Guidance on the options for the construction of the deck, vapour control and water proof layers.

Finding a contractor:

Roofing is a skilled job and when considering employing someone to complete it, home owners should ensure that competent professionals are selected. As with any construction work, it’s wise to obtain several quotes before making a commitment. The guide details what should be included within the quotation.

Other information: Health and safely considerations, guarantees and useful contacts.

Download the guide or read online

The guide runs to around 16 pages, not overly long but with enough detail to inform any householder when assessing the competence of potential contractors or evaluating quotations.

You’ll find a copy here

Article Courtesy of: Gutters London:

Please Note: This Article is 7 years old. This increases the likelihood that some or all of it's content is now outdated.


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