Posted by & filed under Customer advice, Hodgson's.

Hi all and welcome to todays blog, I am Danny Hodgson a Master Chimney Sweep.

Just what nests in chimneys in the UK? why are they bad for the system? how do we get rid of them? and how do we prevent them from entering the chimney system again?

Birds Nests

Birds are the most likely culprits to nest in your chimney/flue system, rooks and jackdaws are the most likely birds to nest in your chimneys.

Jackdaw and rook nesting season generally starts in april and finishes in july but it can start sooner and finish later from mid march to mid august.

The nest is made with twigs and is often lined with hair, rags, hay, bark soil and many other materials. Jackaws nest in close proximity to rooks.

This makes the nests very difficult to remove as they often compact on the bends of the chimney. You will see the jackdaw and rooks enter the chimney system dropping twigs, barks and other objects to build there nests.

A huge nests removed by hodgsons chimney sweeps in devon

Image courtesy of waltham black chimney sweeps

Why are birds nests an issue?

  • Birds nests often completely stop the airflow in the chimney system.
  • They are “live” and carry bugs and bacteria.
  • They absorb moisture, this means due to lack of flow moisture ends up passing through the chimney into the brickwork usually in the bedroom area of the flue.
  • Birds and young can die in the system leaving the chimney full of dying flesh, this causes maggots and bluebottles to fill the chimney and property.
  • Birds fecal matter carries a nasty lung disease called histoplasmosis.
  • The nests are flammable and cause major chimney fires.
  • Due to the blockage the nests can cause carbon monoxide poisoning.
A 1 tonnes bag filled with a birds nest

Image courtesy of waltham black chimney sweeps

How can we get rid of birds nests?

Your professional chimney sweep can remove the nest when the younglings have fledged, if a nest is removed where young and eggs are still present unless the fire is a primary heating source you can be liable for a £5000 fine. A permit can also be purchased by the chimney sweep to remove and destroy live young if the nest is causing a health risk to the occupier.

We use state of the art equipment to make removing your birds nests as efficient and as quick as possible. Using a nest buster and rotary powersweeping equipment to break through the nest, breaking it down and removing it layer by layer checking with a cctv camera that the nest is completely clear of the system.

Hodgsons chimney sweeps using Poly sheeting to make removing birds nests from chimneys as mess free as possible

Mr craig forster set up for removing birds nests

Hodgsons chimney sweeps use the nestbuster to remove birds nests from chimneys across devon

The “nestbuster” courtesy of mark hart RPS

How can we prevent them?

Once the nest is removed a suitable chimney cowling must be installed to prevent further nesting.

A hightop birdguard preventing seagulls entering the chimney system installed by hodgsons chimney sweeps devon

Hightop birdguard preventing seagulls

Wasps and bees nests

Wasps and bees nest in chimneys and flues too. They create a honeycombe type nest which is rock hard and sometimes full of honey. This nest causes a complete blockage in the system and must be removed. Due to the structure, the bees and wasps nests are extremely flammable. Do not light the fire if you see bees or wasps a chimney fire is likely and so is carbon monoxide poisoning.

Large bees nest blocking the chimney system

Large bees nest in chimney

Due to the nature of bees and wasps pest control must be called first to kill the bees or wasps, it is very unlikely that the bees can be relocated due to where they nest in the chimney.

Once the bees nest is fumigated the chimney sweep can remove the remainder of the nest, the best way to do this is with an old set of rods and brushes as they will become very sticky.

The flue must then be heated with a heater to dry the remainder of the honey filled nest and you repeat the process. The flue must then be cctv inspected to ensure the nest is removed.

A wasps nest is a similar process but there is no honey.

There is no prevention method for wasps and bees nests but a hightop birdguard is a good starting point.

Squirrels nests

Squirrels nest in chimneys too! They are also very territorial and carry some nasty diseases;

  • Salmonellosis – Salmonella bacteria found in their droppings causes diarrhea, abdominal cramps, and fever.
  • Lyme disease – spread by the ticks squirrels carry and symptoms include nerve pain, stiffness, and inflammation of the brain or spinal cord.
  • Tularemia – an unpleasant condition that brings about swollen lymph nodes and ulcers.
  • Leptospirosis – symptoms include fever, headache, vomiting, jaundice, and rash.
  • Rabies – though rare, sometimes squirrels pass this virus onto humans via biting or scratching.

A squirrels nest is built similarly to a birds nest and is removed and prevented in the same way. If squirrels reside in the chimney flue, then pest control need to remove the squirrels before the nest can be removed.

So, in conclusion nests cause damp, carbon monoxide poisoning, chimney fire, disease and infestation the only sensible and reasonable option is to remove the nests and prevent them. If you hear scratching or fluttering inside your chimney then it is time to call on you professional chimney sweep.

Thank you for reading Danny Hodgson Master Chimney Sweep Hodgsons Chimney Sweeps

10 Responses to “Critters and birds in chimneys, why evict them?”

  1. Glen cox

    Cheers mate good read
    In relation to birds nest up hear any way we cannot remov a nest unless it’s a primary source of heat or you incur a £5000 fine
    You do say after fledgling have left

    • Daniel Hodgson

      Thats correct but if they are causing a nuisance and a health risk then you can get a permit to remove them. We as a rule wait until the birds have fully fledged before we remove a nest.

  2. Dave Cole

    Many thanks Daniel and also also allowing fellow sweeps to use such educational material and spread what we are all passionate about Chimney Sweeping and more importantly safety. Brilliant article easy to read and digest.

  3. Russell Peace

    Fantastic Blog. I still can’t pronounce some of those disease names. All very unpleasant. Good stuff.

  4. Paul Bates

    I have a slightly different problem. I have Rooks living in my chimney stack. They enter through a hole in the side where part of a brick is missing. I presume there is a void space between the brickwork and the chimney itself. I want the hole in the brickwork filled and the pointing repaired. It is now the middle of September, but it think the birds live there all year round. How do I stand with filling that hole? Can the birds be smoked out with a smoke pellet?


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