If you have a deteriorating chimney stack in March and cannot get a roofer out immediately, knowing what you can safely monitor and what you should leave well alone can prevent a manageable problem from becoming a serious one.
A chimney take-down is the safe, permanent removal of a redundant brick stack from the roofline down. The roofer dismantles the brickwork from the top, lowers or removes the rubble safely, then makes good the surrounding roof covering - cutting and fitting replacement tiles or slates to fill the gap cleanly. The flue void below is sealed at the top and capped internally at the fireplace, leaving no open flue and no exposed masonry above the roofline.
This is not a DIY job and it is not a minor repair. It involves working at height, handling heavy masonry, cutting and fitting roof coverings, and sealing a void that runs through the structure of the house. It requires scaffold on most properties and a roofer who understands both masonry and roof coverings. For a straightforward single-flue stack on a standard two-storey house, the typical cost is in the region of £800 to £1,500, including making good the roof and sealing the flue. Scaffold should be included in any quote.
A chimney stack that is visibly cracking, leaning or shedding mortar is not a stable structure. The brickwork is exposed to rain, wind and frost, and the deterioration is usually progressive - what appears to be a surface problem at the mortar joints can indicate deeper water penetration that is undermining the bond between courses. A pot that is loose can fall. A section of brickwork that is leaning can become detached in high winds.
At the same time, not every deteriorating chimney is an immediate emergency. Understanding what you are looking at helps you decide whether you need urgent attention or whether the situation is stable enough to wait for a booked appointment.
Some situations should be treated as urgent and reported to a roofer as soon as possible:
In these cases, the right course of action is to keep people away from the area directly below and to contact a roofer as a priority. If the stack is actively shedding material, consider whether any part of the property below - including neighbouring property - needs to be kept clear.
For a chimney that is deteriorating but not in immediate danger of shedding masonry, there are useful things you can observe without going onto the roof or taking any action yourself.
From the ground, using binoculars if the stack is high, check the overall alignment of the stack. A stack that is plumb - standing vertically with no visible lean - is less immediately concerning than one that has started to tilt. Look at the mortar joints around the pots at the top. Mortar that has crumbled away from the joint entirely, leaving the pot sitting loose, is a concern. Mortar that is cracked but still present in the joint is a problem, but a slower-moving one.
Inside the loft, after any significant rainfall, check the area of felt and timber directly below the chimney stack. Any drips or staining suggest the flashing has failed or that water is tracking in through the brickwork. Take a photograph of anything you find and note the date - this information is useful for the roofer when they come to assess the job.
There are several things homeowners sometimes attempt while waiting for a roofer that can make matters worse or create new hazards.
It is tempting to get up there and have a look, or to try to push a wobbling pot back into position. Walking on a pitched roof without the right footwear, training and fall arrest equipment is dangerous. Tile roofs are slippery when wet and can be fragile underfoot, particularly around an already-weakened chimney area. A loose stack also makes the immediate roof surface around it less predictable - tiles may have been disturbed by water penetration into the structure below. Leave the roof itself to the roofer.
Blocking a flue opening with expanding foam, rags, or quick-set sealant is not a safe interim measure. If there is any residual combustion risk - even in a fireplace you have not used for years - blocking the flue without proper assessment can cause problems. Expanding foam in a flue void also makes the proper sealing work more difficult and expensive when the roofer arrives.
Applying fresh mortar to the joints of a chimney from a ladder might seem like a sensible short-term measure. In practice, working on a chimney stack from a ladder is unstable and dangerous. You cannot apply mortar properly, or assess what is underneath it, from that position. A temporary repair that looks as though something has been done can also delay a proper assessment, because it obscures how far the deterioration has progressed.
Putting a tarpaulin over a chimney stack might seem to protect it from rain while you wait. In most cases it does not seal effectively around the stack, it can create wind loading on an already unstable structure, and it can trap moisture against the brickwork. If the chimney has failed flashing, a tarpaulin will not prevent water from tracking in at the base of the stack. Leave it uncovered and instead note the weather and check the loft after rain.
When you have a site visit booked, there are practical things you can do to make it go smoothly. If there is access through the loft to the area above the old chimney, make sure there is a clear path to it. If the fireplace below is in a room with furniture directly in front of it, move anything that would make it difficult to work in that area. Have a note of when you last used the chimney, if ever, and whether there have been any previous repair visits and what was done.
If you have already noticed damp patches inside, photographs with dates help the roofer understand how the problem has progressed. This is particularly useful in distinguishing between a very recent failure and one that has been developing over a longer period.
Scaffold is usually erected the day before or the morning the job starts. The take-down and make-good on a standard single-stack property typically takes a full working day. Once the scaffold is up, the roofer will carry out a closer inspection before starting work - this is when any additional findings, such as damage to the surrounding tile work, will be reported to you. All rubble and waste should be removed from site by the contractor.
Inside the house, the final stage is sealing the flue void at the fireplace. This creates a brief period of dust in the room concerned. It is sensible to protect furniture and flooring in that room before the work begins.
Ely Roofers carry out chimney take-downs in March and the surrounding area. If you have an urgent concern about a chimney stack, call us to arrange a site visit so we can assess the condition and advise on the right course of action.
No obligation · We usually respond within 2 hours
Storm damage, active leak, damaged ridge - we aim to be on-site within 24 hours.
