Wi-Fi & routers

Wi-Fi signal is weak through walls

Thick walls, brick, concrete, and metal all block Wi-Fi signal significantly more than drywall, so weak signal in certain rooms is often about building materials, and the fix is usually router placement or additional access points.

Difficulty
Moderate
Time
30–60 minutes
DIY cost
$0–$150
Pro cost
$150–$400

Symptoms

  • Signal is strong in the room with the router but drops sharply one room away
  • Older homes or homes with plaster/brick walls have worse coverage than expected
  • Basements and rooms behind bathrooms (tile/plumbing) are especially weak
  • Signal improves noticeably with doors open

Likely causes

  • CommonDense building materials blocking signal (brick, concrete, plaster, tile)These materials absorb and reflect Wi-Fi signals far more than wood or drywall.
  • CommonRouter placed low, in a corner, or in a closetA router's antennas radiate signal outward and downward less effectively when boxed in or near the floor.
  • PossibleMetal objects or large mirrors near the routerMetal reflects Wi-Fi signals and can create dead spots.
  • PossibleSingle router trying to cover too large or oddly shaped a spaceOne access point has a practical coverage limit regardless of walls.

What to do

  1. Move the router to a central, elevated location, like a shelf in a hallway, rather than a corner or closet.
  2. Angle external antennas (if present) vertically for horizontal coverage, or in a mix of positions if coverage is needed on multiple floors.
  3. Identify which walls are the thickest or made of brick/concrete/tile, and consider whether the router can be placed on the more open side of the home relative to those walls.
  4. For persistent dead zones caused by construction materials, add a mesh node or access point on the far side of the problem wall rather than trying to push signal through it.
  5. Consider a wired connection (Ethernet over existing cabling, or powerline adapters) to place an access point in a hard-to-reach room instead of relying on Wi-Fi to reach it.
  6. Test coverage at different times, since some interference sources (like microwaves) are intermittent.
  7. If coverage remains poor despite repositioning, a whole-home mesh system is usually more effective than trying to boost a single router's range.

Tools and parts

  • Smartphone to check signal strength
Mesh wifi system or powerline adapter kitSearch: “mesh wifi system powerline adapter”

When to call a pro

For older homes with dense walls, a low-voltage technician can run Ethernet cable to key rooms for the most reliable fix.

Safety

Generally low risk

Generally low risk for a careful person. Stop if anything looks different from what this guide describes.

Related guides

Operator provides AI-generated troubleshooting information. It can be wrong. For safety-critical, electrical, gas, structural, medical, automotive safety, or other high-risk problems, consult a qualified professional.