Draught proofing can help keep your home warmer and reduce wasted heat. It can also make rooms feel more comfortable.
However, not every flow of air is a draught.
Your home needs some ventilation to remove moisture, smells and stale air. So, the aim is to stop unwanted draughts without blocking the ventilation your home needs.
What Is a Draught?
A draught is unwanted air moving through a gap in your home.
Common places include:
- windows
- outside doors
- floorboards
- loft hatches
- letterboxes
- gaps around pipes and cables
- unused chimneys
Warm air can escape through these gaps while colder air enters.
As a result, rooms can feel colder and your heating may need to work harder.
Finding and sealing unwanted gaps can therefore be a simple way to reduce heat loss.
Draughts and Ventilation Are Different
It is important to know the difference.
Draughts are unwanted gaps that let air move in or out.
Ventilation is planned airflow that helps keep your home healthy.
Good ventilation helps remove:
- moisture
- cooking fumes
- smells
- stale air
- indoor pollutants
Without enough ventilation, moisture can build up. This can increase condensation and the risk of damp and mould.
So, don’t try to make your home completely airtight by blocking every source of airflow.
Instead, seal unwanted gaps and keep proper ventilation working.
Check Your Windows
Windows are a good place to start.
Check around opening parts of the window for gaps. If you can feel cold air coming through when the window is closed, suitable draught-proofing strips may help.
However, don’t block anything designed to provide ventilation.
For example, many windows have trickle vents. These small vents allow fresh air into the room even when the window is closed.
They are there for a reason, so don’t seal them because you can feel cooler air nearby.
Learn more: Windows, Doors and Floors →
Check Outside Doors
Next, check your outside doors.
Look for unwanted gaps around:
- the sides
- the top
- the bottom
- the letterbox
- the keyhole
Suitable seals, brushes or covers may help reduce draughts.
However, make sure the door can still open, close and lock properly.
Also, never cover a ventilation opening simply to stop cold air.
Check the Loft Hatch
Warm air rises, so gaps around a loft hatch can allow heat to escape into the loft.
Check that the hatch fits and closes properly.
Draught-proofing strips around its edges may help create a better seal.
The hatch itself may also benefit from insulation.
Learn more: Insulation and Heat Loss →
Check Floors and Skirting Boards
Older homes with suspended timber floors can sometimes have draughts through gaps in floorboards or around skirting boards.
Suitable fillers or sealants may help with some of these gaps.
However, there is an important difference between draughts inside the room and ventilation under the floor.
Suspended timber floors often need airflow underneath them to help prevent moisture building up.
So, never block outside air bricks or other vents that ventilate the space below the floor.
Check Unused Chimneys
An open chimney can allow a lot of air to move in and out of a room.
If you no longer use the chimney, it may be possible to reduce this airflow.
However, don’t simply seal it completely.
Unused chimneys can still need ventilation to help prevent moisture problems.
Most importantly, never block a chimney or flue used by a working fire, stove, boiler or other fuel-burning appliance.
If you are unsure whether a chimney or flue can be safely draught-proofed, get professional advice.
Check Around Pipes and Cables
You may also find small gaps where pipes or cables pass through walls, floors or cupboards.
Some of these gaps can be sealed.
However, you need to use a suitable material for the location.
Take particular care around:
- boilers
- fires and stoves
- flues
- hot pipes
- electrical cables
If you are unsure whether a gap should be sealed or what material to use, get suitable advice.
Why Does Ventilation Matter?
Everyday activities add moisture to the air inside your home.
These include:
- cooking
- showering
- bathing
- drying clothes indoors
- breathing
That moisture needs somewhere to go.
If it stays inside, the air can become more humid. When warm, moist air reaches a cold surface, condensation can form.
Over time, regular condensation can increase the risk of damp and mould.
Good ventilation helps remove this moisture before it becomes a problem.
Use Extractor Fans
Kitchens and bathrooms can produce a lot of moisture in a short time.
Extractor fans help remove that moisture at its source.
Use them when:
- cooking
- showering
- bathing
You may also need to leave the fan running afterwards while the room is still damp.
If your extractor fan comes on automatically or continues running for a while after you leave the room, let it do its job.
Don’t switch it off simply to stop the noise or save a small amount of electricity.
Keep Trickle Vents Open
Trickle vents provide a small amount of background ventilation.
They are usually found at the top of windows or window frames.
Because they let outside air enter, you may sometimes notice cooler air around them. However, that does not necessarily mean something is wrong.
They are designed to provide ventilation.
So, don’t block or seal trickle vents as part of your draught proofing.
Open Windows When You Need Extra Ventilation
Opening a window can quickly bring fresh air into a room and let moist air escape.
This can be particularly useful after:
- cooking
- showering
- bathing
- drying clothes indoors
- activities that create a lot of moisture
However, leaving windows slightly open for long periods during cold weather can waste heat.
When extra ventilation is needed, opening windows more fully for a shorter period can sometimes be more practical.
Your home’s ventilation needs will depend on its design, how many people live there and how you use it.
Watch for Condensation
Condensation happens when moist air reaches a surface cold enough for the water vapour to turn into liquid.
You may notice it on:
- windows
- outside walls
- cold corners
- around window frames
- behind large furniture
A small amount of condensation from time to time does not always mean there is a serious problem.
However, regular or heavy condensation is worth investigating.
It can be caused by:
- too much moisture in the air
- not enough ventilation
- cold surfaces
- poor insulation
- inadequate heating
- a combination of several factors
So, don’t assume that simply opening a window will always solve the problem. It is better to look at what is causing the condensation.
Don’t Make Cold Walls Worse
Large furniture placed tightly against a cold outside wall can reduce airflow behind it.
Wardrobes, cupboards, sofas and beds can trap cool, damp air between the furniture and the wall.
Because very little air moves through this space, the wall can stay colder and moisture can collect on its surface. This can make mould more likely.
The problem may go unnoticed because it is hidden behind the furniture.
Where possible, leave a small gap between large furniture and cold outside walls. This allows air to move behind it.
If you have a choice, placing large furniture against a warmer inside wall may also help.
Check behind furniture from time to time, especially during colder months.
Look for:
- condensation
- damp patches
- musty smells
- black spots
- other signs of mould
Finding a problem early can make it much easier to deal with.
Key Points
- Draught proofing can reduce heat loss and make your home feel warmer.
- Don’t block all airflow. Your home still needs ventilation.
- Seal unwanted gaps, rather than vents designed to let fresh air in.
- Check windows, doors, loft hatches, floors and gaps around pipes and cables for unwanted draughts.
- Keep trickle vents and other necessary ventilation open.
- Never block air bricks that ventilate the space beneath a suspended timber floor.
- Never block a working chimney or flue.
- Use extractor fans when cooking, showering and bathing.
- Watch for regular condensation, as it can be a sign of excess moisture, poor ventilation, cold surfaces or other problems.
- Leave some space behind large furniture on cold outside walls to help air circulate and reduce the risk of mould.
- The goal is simple: keep unwanted cold air out while allowing your home to breathe.
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