What Type of Window Screen Keeps Out the Most Bugs?

Window screens exist for one primary purpose: keep the fresh air in and the bugs out. But not all screens do this equally well. Mesh size, material, and installation quality all affect how effective your window screens are at blocking insects — from mosquitoes to gnats to larger pests.

Understanding Screen Mesh Size

Mesh size is measured in "count" — the number of openings per inch. Standard window screens use an 18 x 16 mesh (18 threads per inch horizontally, 16 vertically). This is fine enough to stop flies, moths, and most larger insects.

For smaller pests like no-see-ums, gnats, and tiny midges, you need a finer mesh:

• 20 x 20 mesh: Blocks standard insects plus smaller pests
• No-see-um screen (20 x 20 or finer): Specifically designed to stop tiny gnats and biting midges

Best Screen Types for Keeping Out Bugs

1. Fiberglass with Fine Mesh (Best All-Around)

Standard fiberglass at 18 x 16 or upgraded to 20 x 20 is the most common and reliable choice for everyday insect prevention. It’s flexible, affordable, and effective against most household bugs.

2. No-See-Um Screen

If you live near water, in wooded areas, or deal with tiny biting insects, no-see-um screens offer a finer mesh that stops even the smallest pests. The tradeoff is slightly reduced airflow.

3. Aluminum Screen

Aluminum mesh at 18 x 16 performs similarly to fiberglass for bug blocking. Its rigidity can help maintain the mesh structure better over time, which means fewer gaps for insects to sneak through.

4. Solar Screens

Solar screens have a tighter weave than standard screens, which does provide some additional bug barrier. However, they’re primarily designed for heat and UV control, not insect prevention specifically.

What Doesn’t Affect Bug Blocking

Contrary to what some might assume, screen color doesn’t affect insect-blocking ability. Charcoal and black screens are popular because they offer better outward visibility, but they perform the same as gray or aluminum screens when it comes to bugs.

Installation Quality Matters

Even the best screen won’t keep bugs out if it’s not properly installed. Gaps around the edges, loose spline, or a poorly fitting frame all create entry points. Professional installation ensures a tight fit with no gaps.

Frequently Asked Questions

What mesh keeps out mosquitoes?

Standard 18 x 16 fiberglass or aluminum mesh effectively blocks mosquitoes. For extra protection, a 20 x 20 mesh provides added security.

What screen keeps out the smallest bugs?

No-see-um screens (also called fine mesh or ultra-fine screens) are designed to block even the tiniest gnats and biting insects.

Do window screens keep out all bugs?

Well-maintained, properly installed screens with an appropriate mesh size block the vast majority of insects. No screen is 100% bug-proof, but fine mesh screens come close.

Window Screen Guys — The Right Screen for Every Bug Problem

Not sure what mesh you need? Window Screen Guys helps homeowners throughout Southern California choose and install the right screen for their specific insect concerns. Contact us for a free consultation.