FAQ’s

Question: Why can I smell smoke upstairs when I light my fire?
Answer: If you can smell smoke in other rooms when your fire is lit, it is likely that your flue, which is the pipe running up inside the chimney, is leaking. It is important to remember that the inside of your chimney is liable to degrade with age and use in much the same way as the external structure does.
It is recommended that to protect the integrity of the internal structure of your chimney or flue and to ensure that it is safe to use that you have it professionally lined.

Question: Why do bits of brick and cement fall into my fireplace?
Answer: If your chimney is constructed from brick, the bricks may degrade and crumble over time and it is likely that the mortar in between the bricks will degenerate as well, causing them to come loose and fall into your fireplace. Any lumps and bumps caused by the uneven bricks on the way up through the flue will slow down the flow of the smoke. The smoke will cool and leave deposits on the side of the flue which can be dangerous as a build-up will quickly occur and increase the risk of a chimney fire.

Also, smoke will travel most efficiently through a smooth flue, so to get the best performance from your open fire or multi fuel stove or wood burner the smoke needs to exit via the flue as quickly and smoothly as possible. The disintegrating flue may also leak smoke into other rooms within your property. Any sign of degradation of the internal brickwork means that your chimney will have to be lined before it is safe to use.

Question: Do I need to line my chimney if I am installing a woodburner?
Answer: Yes, you do. Your woodburning stove will have been designed to work with a flue of a specific size. If the flue is too small your stove is likely to spill smoke and could cause carbon monoxide poisoning. If the flue is too big the smoke will cool rapidly in the flue causing tar and residue build-up which is a fire risk. An over large flue will also reduce the performance of the woodburning stove.

Question: What do I need to do to board up my chimney?
Answer: If you are planning on boarding up your chimney because you no longer wish to use it, make sure that the flue is swept and is as clean as possible before boarding it up. Any soot that is left in your chimney contains hygroscopic salts which attract moisture through osmosis from the atmosphere. These salts will make the chimney damp and smelly and can impregnate the masonry leaving you with a permanent problem. An unused chimney should also have a source of ventilation to prevent condensation.

Question: Is my chimney causing damp in my house?
Answer: Chimneys can suffer from damp for a number of reasons – rainwater getting in, condensation and the presence of hygroscopic salts.
Salts from the smoke that pass through the flue can be deposited in the internal masonry – this often happens in older properties where the fire would have been used regularly many years ago. As a result, the masonry builds up a level of salt which attracts moisture from the atmosphere through osmosis which causes damp to appear around the chimney.

The effect of hygroscopic salts can be experienced whether the chimney and flue are in use or not; they can also be worsened if a flue has been made redundant by being sealed off at one or both ends without effective ventilation.

Question: How do I find out what is causing the damp in my chimney?
Answer: There are various different causes of damp in a chimney stack including the following:

The Chimney stack – an open topped chimney stack can allow rainwater to trickle down into a flue. An unused flue can be capped to stop rainwater getting in – it does have to be well ventilated though to prevent a build-up of moisture.

Guttering – any guttering located near a chimney stack that gets blocked up with leaves and other debris could overflow and cause water to run down the adjacent wall and enter via any cracks in the mortar work.

Mortar – if the mortar used to seal the bricks of your chimney stack together is cracked or crumbling, water can enter the chimney.

Lead flashing – the seal where the roof joins your chimney stack is covered with lead flashing. If it is coming apart or there are any cracks, this is a possible entry point for water.

A blockage in the flue – anything in the flue that might prevent ventilation and also act as a sponge for water entering a flue such as a birds nest or rubble, can contribute to damp.

Condensation from a boiler or appliance – can also cause damp in a chimney

Shared chimneys – It is not unusual for a chimney to contain more than one flue and each flue will serve a different fireplace. If you share a chimney with your neighbour, it would be useful to find out if they have had any work done to their flue which may have impacted on your flue.

Identifying the cause of damp in chimney may not be straightforward. The signs of damp may only appear during certain prevailing weather conditions – e.g. a combination of wind and rain coming from a certain direction. Or it may be a combination of causes that are contributing to the damp – problems with lead flashing and condensation from a boiler for example. Read more about damp here.

Question: How do I get rid of damp in my chimney?
Answer: There are various things that can be done to reduce or eliminate the presence of damp in a chimney.
Clearing any blockages in a flue and ensuring a suitable level of ventilation are both critical to maintaining a flue. Regularly reviewing the condition of guttering, mortar and lead flashing around a chimney will all be beneficial.

Question: How often should my chimney be swept?
Answer: How often you have your chimney swept will depend on a number of factors which include the type of fuel used, appliance, duration of use, moisture content of wood fuel and the type of chimney you have. Your chimney sweep will be able to advise on the sweeping frequency during the appointment.

It is recommended that you have your chimney swept at the following intervals for the different fuel types shown:
Smokeless fuel: At least once a year
Wood – Quarterly when in use
Bituminous coal – Quarterly when in use
Oil – Once a year
Gas – Once a year

Question: Do I need to sweep my chimney if I have had the flue lined?
Answer: Yes, you do. A lined flue can accumulate cobwebs and other debris in the same way that an unlined flue can. Your chimney should be swept at different intervals depending on the type of fuel that you are burning, as shown below:
Smokeless fuel: At least once a year
Wood – Quarterly when in use
Bituminous coal – Quarterly when in use
Oil – Once a year
Gas – Once a year

Question: I have an open fire / woodburning stove – do I need to fit a carbon monoxide alarm?
Answer: If you have either a woodburning stove or open fire Document J of Building Regulations requires that a carbon monoxide alarm is installed within 3 metres of the appliance.

Question: Is a permanent air vent essential?
Answer: A fire will always need a source of air to burn. Properties that have been built after 2008 with air permeability reduced to certain levels will require an air vent to work properly. All open fires require ventilation equivalent to 50% of the cross-sectional area of the flue. Position of the ventilation within the room is critical to prevent the feeling of draughts.

These are just a selection of questions that we regularly get asked.  If we haven’t covered your specific problem here and you would like more information please contact Turner Baker on 01432 839123