Road noise reduction in the balcony

Question

I am living in an apartment which has a balcony right next to the small road. Even thought the road is quite small, cars are still driving there and it makes a lot of sound if the doors to the balcony are open.

The balcony has no solid vertical wall toward the road, but only iron bars every 20cm. Would that help if I would put on the ground a half of meter height plastic (or other material) board over the length of the whole balcony next to the iron bars?

I don't expect 50% of noise reduction but at least little bit would be good.

To illustrate my point, this is how it looks:

Answer 1

Different sound frequencies have very different characteristics in terms of what you can do and how effective it will be. The road noise is a mixture of sound frequencies. There probably is nothing practical you can do about the low frequency noise, but you might be able to muffle the sound a little by reflecting high frequencies and absorbing mid frequencies.

Think in terms of the sound panels used to create cubicles to reduce office noise. They aren't real effective, but they help a little. You could even start by experimenting with ones you find in a used office equipment store. You could also make your own. Plywood with thick carpet padding glued on, and a protective cover would be a reasonable first test. But making either of these weatherproof will be a challenge.

For more naturally weatherproof materials, you could look at T1-11, thick, dense styrofoam panels, or even corrugated plastic panels for the backing, and closed-cell foam sheets (the material used for boating applications) for sound absorption.

Of course those would totally block your view. If you have a lot of money to blow, you could try clear Lexan panels.

Answer 2

I would suggest that any part of the balcony open area that you close off will help reflect some of the sound back out toward the road. The only real way to know how much it helps would be to try it. It could be cheap to try getting some large corrugated cardboard cartons from an appliance store that you could cut up and place along the railing in a temporary manner to see if the noise reduction was suitable for you.

Note that since this is an apartment and you are most likely just a renter you want to be very careful to not do anything that is permanent or modifies the basic structure. What ever you do wants to be easily removable without leaving any trace that it was there.

Answer 3

You could encourage your apartment managers to let you plant a row of thick hedges by the roadside. Thick vegetation does a surprisingly good job of cutting road noise.