top of page
Strip backgrouynd showing a desk with paper, pen and coffee cup


Hot Topic Highlight – Why can Chimney Breasts be Problematic?

Updated: Oct 28, 2023

Building a Better You

Property Elite’s sole aim is to build better property professionals - supporting your career every step of the way, whether you are an AssocRICS or RICS APC candidate or a MRICS or FRICS Chartered Surveyor simply seeking engaging CPD.

We provide a wide range of training and support, so why not find out more on our website about how we might be able to support you? We work with candidates across all RICS APC and AssocRICS pathways, routes to assessment and geographic regions.

Don’t forget to sign up online for your free 15 minute AssocRICS or RICS APC consultation, including a review of your referral report if you have been referred. You can also book your bespoke training or support services directly through our eShop.

Not sure about signing up? Make sure you read what our recent successful candidates have to say in our Testimonials.

What is today's blog about?

In this week’s blog, we look at the potential implications and risks relating to the removal of chimney breasts. This is essential reading for RICS APC and AssocRICS candidates pursuing the Building Pathology, and other related, technical competencies.

Why are chimney breasts removed?

Chimney breasts first became a feature in residential buildings in the late medieval period, when brick became available as a building material. They became common in the 17th and 18th centuries when the use of coal became widespread.

However, in many buildings, fireplaces have stopped being used and their chimneys have been blocked up. The exception to this is the modern trend of installing wood burning stoves in both old and new buildings.

Disused or blocked up chimneys can lead to a variety of issues, which we will discuss below.

Furthermore, as chimney breasts take up space in rooms and can create unused or unusable space, many homeowners seek to remove them altogether.

What issues do disused chimneys create?

Disused chimney breasts come with a variety of issues. Most commonly is damp, due to a variety of potential causes:

  • Water penetration down uncapped, open flues

  • Water penetration through the walls of the chimney, particularly in exposed locations, side stacks or chimneys with offsets. Poor pointing, cracks, lack of flaunching or the use of inappropriate materials (e.g., cement rather than lime mortar) can exacerbate the problem

  • Condensation within blocked flues due to a lack of ventilation

  • Hygroscopic salts, which form when fossil fuels are burnt. They attract moisture and can affect internal plasterwork

  • Carbon staining due to water reacting with carbon deposits in the chimney

There are several ways to deal with the above causes of damp, including:

  • Installing a ventilated cap to the top of the chimney stack. A competent roofer or chimney sweep should be able to do this at relatively low cost

  • Installing internal ventilation to the chimney breast, usually where the chimney stack has been removed. Internal to external ventilation could also be considered for internal chimneys

  • Installing a flue balloon or a damper (if the chimney may be occasionally used)

What issues does chimney breast removal lead to?

Many homeowners will decide to remove the chimneybreast completely, to open rooms up, add additional space or remove the maintenance liability if the chimney breast is in particularly poor condition.

However, removing a chimney breast can be expensive and time consuming. It will also require Building Control approval (see Part A of the Building Regulations) and the input of a structural engineer, as severe structural damage can be caused if the chimney breast is also a loadbearing wall.

The structural engineer will issue calculations and advise on how the building will be supported after the chimney breast is removed. This could include the use of gallows brackets or if these are not suitable, then installing fire-protected steel beams.

Inappropriate methods of supporting the structure, include corbelled brickwork and timber bearers fixed into the existing floor or ceiling joists.

Further considerations when removing a chimney breast include:

  • Checking if the property is in a conservation area or if it is a listed building, where additional constraints or approvals may be required

  • Checking if the chimney breast also forms a party wall and complying with the Party Wall etc. Act 1996

  • Isolating or removing any services contained in the chimney breast prior to works commencing

Planning consent is generally not required as removal of a chimney breast is generally classed as Permitted Development.

Why do I need to know this as a surveyor?

As a surveyor, it is important to know about the construction of buildings and to be able to identify key defects (and follow the trail to provide a diagnosis, if within your scope of competence.

In particular, if you are inspecting a property then it is important to identify if a chimney breast has been removed and if you need to refer the client to their solicitor for confirmation of Building Regulations approval and to check if there was a party wall agreement for the work. You should briefly advise your client about the implications if these have not been obtained, but leave the detailed advice to the solicitor.

More importantly, if only part of the chimney breast has been removed, you need to be able to determine if adequate support has been installed to support the floors. More than likely, you will need to recommend a further intrusive investigation.

Finally, do not forget to check in the roof space to ensure that any remaining chimney breast is adequately supported. This could be the case where the chimney is shared at roof level and could not be removed.

How can we help?

Stay tuned for our next blog post to help build a better you.

N.b. Nothing in this article constitutes legal, professional or financial advice.


Commenting has been turned off.
bottom of page