Last updated: February 2026
Guide Summary
- The correct hole size (also known as aperture) for your insect mesh depends on the type of insects you are looking to keep out.
- Most UK insects will be kept out using a 2mm x 2mm hole size or less
- You will need a finer mesh with a smaller hole size less than 0.5mm x 0.5mm to keep out tiny insects such as midges and fruit flies.
- Visibility through the insect mesh will depend on the open area of the material. The higher the open area, the more transparent the mesh will be.
- Consider the right material for your insect mesh to ensure that it is tough enough for high-traffic areas such as windows and doors. You may need to use a thicker material.
- Choosing the correct material is a balance between the right hole size to keep insects out, the right thickness to ensure robust and hardwearing protection, and sufficient open area to allow ventilation and light through.
Choosing the right insect mesh for your windows and doors
Windows and doors are key entry points for insects, particularly in the warmer months when you want to leave them open. Choosing the right insect mesh can be daunting, as there is a wide variety of options available in different hole sizes, thicknesses and finishes. We regularly advise our customers on the best option to suit their insect proofing requirements.
A particular concern for our customers is to keep insects out while not compromising the light and air that is able to pass through the insect mesh, allowing them to still enjoy a good level of visibility and ventilation through their windows and doors.
This guide explains the best options available for the type of insects you are looking to keep out, and how to tell if the insect mesh will still allow light and air through.
Who is this guide for?
This guide is for anyone looking to keep insects out of key entry points such as windows and doors, whether in your home, office or commercial premises such as a professional kitchen. The guide provides expert advice based on the solutions we provide for our customers every day.
In this article...
- Guide Summary
- Choosing the right insect mesh for your windows and doors
- Who is this guide for?
- Why are windows and doors a common entry point for insects?
- What size hole do I need to keep insects out?
- Open area is important when choosing insect mesh for windows and doors
- Common mistakes when choosing insect mesh for windows and doors
- What to take away...
- Insect Mesh Aperture Size FAQs
It is especially useful if you:
- Have noticed a large number of insects inside your premises.
- Are fitting insect mesh to a window or door.
- Want to ensure that airflow and visibility through the insect mesh isn't compromised.
- Want to leave your windows and doors open in the warmer months.
- Want to know how strong insect mesh should be for windows and doors.
Why are windows and doors a common entry point for insects?
Insects are attracted to the inside of buildings as they have regulated temperature and weather conditions, are often a source of food, and they are attracted to the light inside your home particularly at night. Windows and doors offer the path of least resistance as they are often left open in the warmer months for ventilation. Even doors and windows that look closed can have gaps large enough for insects to find their way in. You may even have insect proofing in place for your windows and doors, but this has degraded or become damaged over time and may need replacing.
What size hole do I need to keep insects out?
Choosing the correct hole size is important, as having too large a hole size in your insect mesh or fly screen will allow unwanted insects to gain entry. For most UK insects we recommend a hole size of 2mm x 2mm or less which will be sufficient to keep out most unwanted guests such as common house flies, horse flies, moths, ladybirds, bees and wasps. For smaller insects such as midges, fruit flies and gnats we recommend using an extra fine insect mesh with a smaller hole size less than 0.5mm x 0.5mm.
How strong is insect mesh for windows and doors?
Hole size isn't the only consideration when looking at insect proofing your windows and doors. As high-traffic entry points, windows and doors are subject to frequent use, making any installed insect mesh or fly screens more susceptible to accidental damage and general wear. Therefore, you may want to consider using a thicker material to ensure that the insect screen is robust enough.
If you use an insect mesh which is too light-weight then there is a risk that this will be easily damaged. We are regularly contacted by customers looking to replace existing insect screens which have been damaged.
For stronger options we recommend stainless steel insect mesh, in particular a heavy-duty stainless steel insect mesh which has a thicker 0.3mm wire. The thicker wire provides a tougher material which is less susceptible to damage.
If you have pets, then we would suggest using a pet-proof insect mesh which has been specifically designed to be more resistant to scratching and tearing by cats and dogs. For more information on the different types of insect mesh material, and their different properties, see our Fly screen comparison table.
Open area is important when choosing insect mesh for windows and doors
Open area is the proportion of the mesh which is not obstructed by material. Essentially it is the empty space that allows air and light to pass through. The higher the percentage of open area an insect mesh has, the more light and air will pass though. For example, most of our standard-weight insect meshes have an open area above 70%. This means that more than 70% of light and air will pass through the mesh.
Why is the open area important? A high open area is particularly important for windows and doors, as you want more air to pass through the mesh for ventilation. You also don't want to obstruct the light passing through, as this will increase the visibility through the material allowing you to see through the window.
How is open area calculated? Open area is determined by the relationship between the hole size and thickness of the material. An insect mesh with a thicker material will usually have a lower open area allowing less airflow and will be less transparent.
Common mistakes when choosing insect mesh for windows and doors
- Selecting a hole size that is too big to keep insects out. Choose 2mm or less for most UK insects, or less than 0.5mm for very small insects.
- Choosing a material that isn't strong enough for high-traffic areas such as windows and doors.
- Using an insect mesh with too low an open area, which reduces airflow and visibility through the material.
What to take away...
Choosing the correct insect mesh is always a balance between the hole size, the material thickness and the open area. Sometimes, we would recommend going with a thicker material and lower open area as it's more important to have a stronger insect mesh for your windows and doors. For other areas, a higher open area may be required for better ventilation. We advise our customers every day on the best option for their specific requirements. For more information on insect proofing see our Keeping flies and insects out of your home guide.
Insect Mesh Aperture Size FAQs
What insect mesh hole size do I need for windows and doors?
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What insect mesh hole size do I need for smaller insects?
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How strong does insect mesh need to be for windows and doors?
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Will I be able to see through insect mesh on my window?
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Does insect mesh restrict airflow?
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Why trust Mesh Direct?
Mesh Direct is a family-run UK specialist established in 1952, with decades of hands-on experience supplying wire mesh, wire netting, and fencing solutions. Our guidance is shaped by real-world use across domestic, trade, and industrial projects, helping customers choose materials that are fit for purpose and correctly specified.
As members of the British Stainless Steel Association and recipients of the Feefo Platinum Trusted Service Award, we provide transparent, expert guidance you can rely on. If you are unsure which mesh is right for your project, our team can offer practical, application-led advice. Contact us for guidance.
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About the author...
Dan is the owner and Managing Director at Mesh Direct, and has extensive knowledge of the mesh industry having advised on mesh and fencing products for over 15 years.
After graduating from Cambridge University in 2003, Dan went on to become a corporate lawyer specialising in commercial litigation at an international law firm. In 2010, Dan joined Mesh Direct, the e-commerce division of his family business originally established in 1952 as a corn, seed and animal housing supplier. Dan’s key areas of expertise include product technical advice, product sourcing, logistics, and B2B / B2C e-commerce.
Dan Hancock, Managing Director
Mesh Direct | LinkedIn
About the author...
Dan is the owner and Managing Director at Mesh Direct, and has extensive knowledge of the mesh industry having advised on mesh and fencing products for over 15 years.
After graduating from Cambridge University in 2003, Dan went on to become a corporate lawyer specialising in commercial litigation at an international law firm. In 2010, Dan joined Mesh Direct, the e-commerce division of his family business originally established in 1952 as a corn, seed and animal housing supplier. Dan’s key areas of expertise include product technical advice, product sourcing, logistics, and B2B / B2C e-commerce.
