Can mirrors block my wifi signal?

8

Due to various constraints, I can not easily relocate my wireless router, and it is currently situated such that there are three walls and two mirrors between the router and my bed, where I frequently lose my wireless signal. Are the mirrors blocking or reflecting the wireless signal, or is it the walls? And what can I do about it?

Ryan C. Thompson

Posted 2010-08-04T20:48:14.697

Reputation: 10 085

1I've seen a similar issue a while ago... Is it double-sided mirrors or single sided? – r0ca – 2010-08-04T21:01:59.477

1Yes, everyone, there is a bathroom between the mirrors. – Ryan C. Thompson – 2010-08-05T04:05:34.547

7Definitly, we need to send this to MYTHBUSTERS! – r0ca – 2010-08-05T12:51:14.847

Apart from amoured concrete mentioned below, there are other reasons to get a bad signal too: 1. another router sending on the same channel (if the other router uses channel 1, use 6) 2. water in pipes 3. bluetooth, microwave ovens, a phone using 2.4 GHz band. Try to move the router 1 meter left, right, up, down and check the signal. – ott-- – 2011-12-26T17:38:47.523

Answers

7

A (fairly modern) mirror shouldn't block your signal.

If there are two mirrors between your bedroom and the router: is there a bathroom, too? If that's the case then i would suspect that the tiles on the bathroom walls are one of the factors leading to your signal loss.

Is the building you live in build from armored concrete (like it's usual in Germany, for example)? Then you'll have another big factor.

lajuette

Posted 2010-08-04T20:48:14.697

Reputation: 4 364

@Ryan: You said there's a bathroom between your bedroom and the router. I'm pretty sure that's the problem. Tiled and/or thick walls with pipes and maybe other metal in the way are most likely the problem.

Setting up a repeater/signal booster in there is probably not a good idea (it's wet and steamy). But maybe somewhere else? Otherwise you should think about relocating your router, using a wire (if possible) or pushing the signal strength. – lajuette – 2010-08-05T13:01:17.527

There's a closet to the side of the bathroom that has a clear shot to both the router and the bedroom. I could conceivably set up a repeater there. – Ryan C. Thompson – 2010-08-05T16:22:26.530

But don't forget: A bathroom is a wet environment. Your repeater should be able to handle a long and steamy shower/bath without short-circuiting. – lajuette – 2010-08-05T20:51:07.800

Everything except a vacuum attenuates WIFI signals, even modern aluminum backed mirrors. – dbasnett – 2010-08-10T14:33:25.890

5

It's conceivable an older mirror could cause issues. The glass shouldn't matter at all, but if they are heavy backed (silver or lead) it could be a problem. You're more likely to experience signal interference from other wireless sources like additional routers, cordless phones, etc.

It could also be the walls, but it would depend on what is in the walls. If it is a wall with a ton of plumbing and wiring, it could effectively block a wifi signal.

JNK

Posted 2010-08-04T20:48:14.697

Reputation: 7 642

3Mirrors usually equal bathroom, and bathroom usually equals plumbing, making that part of your answer a little more likely. – Joel Coehoorn – 2010-08-04T23:04:56.527

3

In a new bath room, much of the plumbing is plastic (PVC or ABS). in an older building it would be copper and cast iron, which will block more of the signal. Bathrooms also tend to have more wiring then other rooms which could block more of the signal. If the walls are tiled, they not only have the tile, but usually have a heavier cement based backer board which will block more of the signal then regular dry wall. Also don't forget the tub. A large cast iron tub would definitely block part of the signal. A fiberglass one would not block as much.

Finally as for the mirror, the silver backing can be expected to block the signal. On older mirrors the coating was actually silver which is an excellent conductor, meaning it would block the signal. Newer mirrors use a thinner silver colored paint usually with at least some aluminum in mix. It will still block at least some of the signal, but not as much as the thicker silver.

In summary, a new bathroom will not block as much of the signal as an older one will.

Jim C

Posted 2010-08-04T20:48:14.697

Reputation: 1 748

Well, my apartment is fairly old, so this might be it. – Ryan C. Thompson – 2010-08-10T04:59:06.347

3

I can tell you for certain that mirrored walls in two adjacent rooms (with a hallway in between) in a 20 year old house absolutely stops all wifi signals dead. There is one mirrored door between the two parts of the house and when it is open, a small amount of signal survives a few feet into the hallway. Door closed: no signal past the door.

It took a few months to diagnose the issue and we are considering a repeater in the attic or perhaps even outside to go around the mirrored walls that transect the house.

Terre Spencer

Posted 2010-08-04T20:48:14.697

Reputation: 31

2

You could get a wifi signal booster and situate in one of the in-between rooms that gets some reception.

FrustratedWithFormsDesigner

Posted 2010-08-04T20:48:14.697

Reputation: 1 298

2

Almost? everything attenuates WIFI signals, aluminum backed mirrors included. Here is a list of some common materials

Attenuation

dbasnett

Posted 2010-08-04T20:48:14.697

Reputation: 459

1

I can say with certainty that mirror doors will stop a Bluetooth signal. I have a sky q mini box that for convenience is placed in a built in wardrobe with sliding mirror doors, if the doors are open even by as little as two inches the box works perfectly, close the doors and it doesn’t work at all.

R.F

Posted 2010-08-04T20:48:14.697

Reputation: 11