Summary: How much does it cost to repair a chimney, average chimney repair costs and average cost of chimney materials.
Damaged chimneys can be dangerous as parts can fall down into the road causing injury. Chimneys need to be inspected regularly on very old properties, particularly if they are high chimneys. Flues and chimneys are subjected to intense heat followed by cooling. Hot gases cause chemical reactions and condensation so the chimney over its lifetime will be subject to a lot of wear and tear. The actual stack itself is exposed to all weathers and consequently repairs and maintenance need to be of a high standard. As well as this, design elements of significance need to be properly conserved.
Average Cost
| Job | Average Cost | Updated | Quote |
| Replace chimney pot | £60 – £100 | 2019 | n/a |
| Repair chimney stack | £500 – £2,500 | 2019 | n/a |
| Rebuilt chimney | £5,000 – £7,000 | 2019 | n/a |
Factors to consider
One question to ask yourself is do you need a chimney? If the property has been modernised and central heating installed and if there is no possibility of a fire being reinstated then it can be a good idea to have the chimney dismantled and taken down altogether. You will need to get advice from a reputable builder as to how this should be done. Also if your building is listed or in a conservation area the chimney may have to remain. Again, your local authority will be pleased to advise.
If the chimney is to stay it is advisable to ask the opinion of a competent builder as to what repairs need to be effected. Get several quotes for the repair job and ask for recommendations. You can attempt this type of job yourself if you feel competent but you will need the various tools required plus a long ladder. Also remember that a builder will be insured against injury or damage to the property and you may not be.
If a chimney is leaning this can present immense problems and the advice of a Building Inspector is recommended. Defective mortar will have to be replaced and the stack stabilised. It is advisable to carry out periodic checks after the work has been done to prevent further leaning occurring.
In some instances, in order to create more living space, chimneys have been removed from inside a house but the stack above has been left. If done correctly this does not present a problem. However, if the remaining chimney stack has not been properly secured it needs to be stabilised. The easiest solution is to use supporting beams on suitable walls or to use brackets.
If you intend to repair a chimney yourself you will need to climb on top of the roof to have a look at the outside of the chimney. To properly see inside you will need to remove the cap and remove any debris and creosote. This is a messy job so wear your oldest clothes, gloves and ideally a face mask.
After cleaning the flue you will need to use a chimney brush to go up and down the flue. The fireplace opening inside the house needs to be sealed with plastic sheeting to prevent debris going into the room.
The lining of the chimney needs to be inspected for cracks so you will need a strong light to check for deterioration. Water that freezes in winter and then thaws out can cause damage. These areas need to be repaired in order to stop moisture seeping into brickwork. There are various types of lining available should this need to be replaced. Cast linings are normally the least expensive and easiest to put in. Other liners are made of metal or concrete. It is advisable to ask the advice of an expert as to what you require as this will normally be determined by the size and age of the chimney.
The flashing round the chimney needs to be examined and replaced if it is damaged as this is where water can seep in. It is beneficial to brush roofing tar around the flashing to protect from moisture damage. The chimney cap keeps out birds and rain so repair this if it is damaged. Alternatively consider installing a cap if your chimney does not already have one.
Costs to consider
If your chimney is totally broken it is possible to get a facsimile replacement. There are some excellent designs on the market. Ask at a builders’ merchant or local DIY store. Another alternative would be to look in an architectural salvage yard where you may find the exact style you require, particularly if the yard in question happens to be near where you live as chimney styles are often the same in a particular area.
All work needs to be done to Building Regulations and you can get advice from your local authority. Legislation regarding building work of all kinds has increased over the last few years and you need to be certain that the work you intend carrying out meets the latest requirements. The Solid Fuel Association will be able to give advice too.