Chimney stack removal costs: What you can expect to pay and what's involved

If you're renovating your property and have inherited a home with chimneys and the stacks aren't needed, or you're adding an extension and need to remove one for practical or aesthetic reasons, you may be considering adding chimney removal costs to your budget.

Or, perhaps it's turning into an area of concern as various parts of it start to break down leading to bigger issues such as damp. Either way, getting rid of it may seem a more sensible option.

But, if you don't already have scaffolding in place and it's a stand-alone job, just what might your chimney stack removal costs stack up to?

Chimney stack vs chimney breast

The good news is your chimney stack removal costs, unlike chimney breast removal costs, are unlikely to require the professional services of a structural engineer or extra structural work to make your chimney stack safe.

A chimney stack is comprised of the visible part of the larger chimney stack that rises above the roofline," explains Charlie Avara, founder and director of BUILD by Charlie.

"These are usually made from brick, flashed with lead to stop water ingress and topped with a chimney pot, which in turn may feature a cowl. Internally a flue will run through the structure to enable smoke to leave the property.

"A chimney stack is sometimes confused with a chimney breast," she adds, "which is the structure that rises up through the floors of the building and can often take up a good deal of living space."

And, while removing a chimney stack means there will be a gap in the roof that needs covering, it doesn't mean you also have to remove the internal parts of the chimney too.

Therefore, when it comes to chimney stack removal costs above roofline, you will simply be paying to cover up the remaining hole that's left, rather than having to support any elements remaining below.

However, if the stack forms a buttress, the whole wall must be checked for stability by a structural engineer before removing the stack above the roofline. This is a much bigger job and may require bigger pockets to pay for the work.

Charlie Avara

After a very successful career as MD of a design and build company Charlie has recently launched her own domestic contracting business, BUILD by Charlie. With over 15 years in the industry Charlie has built up a wealth of knowledge on all things renovating and remodelling with a proven track record of delivering on projects ranging from the ultra modern, through to period properties, working with architects or directly with the homeowners.

Chimney stack types and parts

While the most common type of chimney stack on older houses is one constructed of masonry, there are also a number of other types of chimney stack.

Masonry stacks are made from brick, and contain the following parts, all of which have to be removed:

• Flue - found inside the chimney stack and it's the aperture which vents smoke and gases from the fire or wood burner to the outside
• Chimney pot - found at the top of the flue. It extends the length of the chimney stack and facilitates the creation of a draught to aid combustion in the fire below. The chimney pot may have a cowl which further aids air flow, prevents downdraughts and stops birds from nesting in the chimney pot
• Flaunching - a strong mortar which holds the chimney pot in place and acts as a rainwater barrier from preventing moisture entering the stack
• Flashing - a band of metal, typically lead, which acts as a water-tight seal between the roof and the stack. Occasionally, this flashing may be constructed from mortar

Prefabricated chimney stacks are also available. These are made from glass reinforced plastic and commonly clad with brick slips to make them look more authentic.

Usually supplied with fixing kits, they are easier to install and therefore remove. However, as they are normally used in new builds, it's unlikely you would be investigating the costs to remove one of these types of chimney stack.

If you have a wood burning stove, you may find there is a metal chimney inside your masonry chimney, or as a stand-alone flue. Once again, this will leave a hole in your roof that needs remedial work once you remove the flue.

Costs and factors affecting chimney stack removal costs

"In general, I would recommend budgeting upwards of £6000 for chimney stack removal costs, as a full package cost including scaffolding and retiling the roof," says Charlie Avara.

But there are a number of different costs that can influence this, most of which are similar to many building projects.

1. Permission

"Permission is always the starting point," says Charlie. "As with any large changes to a property you will need to ensure that the works are compliant with the relevant rules and regulations. It's often allowed under permitted development, but not always.

"In the case of a listed property or conservation area it will involve seeking planning permission," she advises. Likewise if the stack is shared, party wall agreement costs will need to come into play and this could add upwards of £700 to your budget.

2. Building regulations

For the purpose of removing your chimney stack above the roofline, you will be required to ensure that the work falls in line with Part A of Building Regulations which relates to structure. It sets the standards to ensure you cover up the hole in the roof caused by removing the stack, with the same materials used to form the current roof structure.

You will need to inform your building control department about the work and ensure it is signed off by the council or an approved inspector. This could cost around £200 & VAT.

3. Difficulty levels

It's then about what you are removing. "Generally speaking, the harder that the chimney stack is to break down and remove the higher your labour costs will be for this," notes Charlie. Plus, labour prices vary across the UK meaning your location will play a part too.

4. Fireplaces

"If you are removing the stack you must ensure that the fireplaces are no longer working, failure to do so is a safety risk," explains Charlie, so if you are also decommissioning the fireplaces this will inflate the cost of the works.

5. Stack condition

"The condition of the chimney stack will also influence the price," she adds. "If the stack has deteriorated to the point that you have problems with water ingress and damp you may need to include additional budget to have these rectified."

6. Access

Throw into the mix access, and costs start to rise. Scaffolding will be required and this may increase depending on how many sides of the building you need to scaffold. If for example it needs to be wrapped around two sides of your home, or you discover damage that takes longer to repair than anticipated, this will increase the cost.

7. Materials

Basic maths dictates that the cost of materials to fill in the gap left in your roof will naturally depend on how large a hole is left and the type of materials required. As well as tiles, you may need battens and roof membrane, slates or tiles. All of which can vary in price.

"You may wish to remove the chimney stack and simply cap it off for example," says Charlie, "or you might need to hunt around for reclaimed peg tiles that are in-keeping with the rest of the roof and have the area retiled.

8. Skip hire

As with materials, the amount of waste generated from removing a chimney stack will dictate the size of the skip required. As will the possible need to keep it on site for longer if you have to do remedial repair work. You may also need a skip permit too Check with your local authority to confirm costs.

Reasons for removal

Before you decide if you want to budget for chimney stack removal costs, it's worth considering the reasons why you may want to remove one.

"As with all elements of a building, what one person considers a carefully chosen design feature, another might think of as an eyesore. In addition to this, chimney stacks are one of the most exposed parts of any building and require ongoing upkeep," explains Charlie Avara. "Removing the chimney stack is a simple way to overcome both of these factors.

"However, a chimney stack should only be removed if the fires connecting to it are no longer in use," says Charlie. "For example, if the original wood or coal burning fireplace has been replaced with an imitation fireplace, in this instance it is possible to remove just the chimney stack and make the roof good afterwards.

"It does get slightly more complicated if you are planning to remove a chimney stack that you share with a neighbour," she adds. "If you intend to remove half of a stack that you share with a neighbour, this is notifiable under the Party Wall Act as you will be leaving the previously internal party wall exposed - something that was not intended at the time of building.

"If you are concerned a good rule of thumb is to consult a party wall surveyor who will be able to help you navigate the legalities and complexities of this process.

In general, the main reasons for considering chimney stack removal costs are as follows:

• The chimney stack is in poor condition and poses a danger
• Leaks are occurring as a result of the condition of the chimney stack causing issues with damp
• To reduce maintenance costs - even if not used it will still need to be kept in good condition
• You want to remove the chimney breast inside your home to create more space and the chimney stack is supported by the chimney breast. Removing it may be simpler than the structural work needed to support the stack once the breast is removed
• For aesthetic reasons - you prefer a cleaner roof line
• You're considering a two storey extension or loft conversion and it has to be removed

Removing a chimney stack: What's involved

Removing a chimney stack involves the following process.

"It goes without saying that removing a chimney stack involves working at height, so hiring a cherry picker or putting us scaffolding is an essential first step," says Charlie Avara. "Not only as a means of working safely but also to help you get the materials back to the ground safely."

"With access in place the chimney cowl and pot will need to be removed, then the brickwork, cement and flashing, before making the roof good again," she explains.

"To do this new roofing felt or breathable membrane will need to be installed, followed by battens and roof tiles," says Charlie. "It is always worth putting time into sourcing reclaimed roof tiles," she adds, "after all a patch of perfectly new tiles will be a bit of an eyesore on a weathered roof.

"The final phase of the project is getting rid of the materials and before you put everything into skip it might be worth considering selling the bricks and the pot," suggests Charlie, "after all if your chimney stack were made of London Yellow Stock bricks for example people are always on the lookout for these for building projects."

FAQs

Are chimney stack removal costs cheaper than repair or maintenance?

"Re-pointing and maintaining the chimney at intervals is the more cost effective option," says Charlie Avara, but this naturally depends on its condition. If it requires a lot of work to get it to a maintainable state, and you have no fireplaces or stoves that require it to be in good-working order, you may find yourself weighing up removal as the better option.

Likewise, if you're renovating a property and don't plan on using any open fireplaces, unless you have capped them off or fitted a chimney balloon, they will also be creating a draught and costing you more money in energy bills.

Can I remove a chimney stack myself?

"I would strongly recommend using a professional if you are looking to remove a chimney stack," says Charlie Avara. "The combination of working at height, ensuring that the roof is watertight and that the finished project is compliant with building regulations mean that the job is best left to the professionals."

Add to this the safety risk of dropping materials and potentially damaging your roof or an individual if you do, it's simply not worth exploring the job as a DIY project

Even if you don't use your chimney with a working fireplace, it's worth remembering that it will still require on-going maintenance like the rest of your home.

However, if you think any current damage isn't enough to incur the risk of debris falling onto the ground, or you're keen to keep it as an architectural feature, find out all you need to know about restoring chimneys and read our step-by-step guide to repointing a chimney to find out just what's involved.