How can I build a wood fence to block sound?

Question

I live on a busy street that is separated from a highway by a restaurant parking lot, and I would like to replace my wrought iron fence with a wooden fence for both privacy and to block sound. I am able to build up to an 8 foot fence, but I'm concerned that it may not be enough to block the ambient sound coming from the street and highway.

Of course perfect silence is unobtainable (and I actually do like some city sounds) but it would be nice to have a little more solitude than I have now.

I'm wondering if there are any tips for making the fence better at blocking sound. For example, would a double-walled fence provide better sound blocking, or would the difference be negligible compared to the sound coming over the fence?

Answer 1

We have lived in our home for a year and a half now. There is constant multilevel noise from the nearby 4 lane hwy - though it does vary in extremes - more at rush hour, less in between and on most weekends. Nights are usually interrupted only by the occasional loud truck or motorcycle. But the nicest weekends in early Spring and Summer are nearly deafening all day with motorcycles. I have not "gotten used to it" in this amount of time and doubt that I ever will. Inside the house, it is greatly reduced, but still omnipresent and grating on the nerves. Radio helps with this, but really, that just amounts to more auditory stimulation, which is already excessive. Also, we both love to be outside.

So, the time has come. We are reading everything we can get our hands on about noise blocking. We do not want to spend a fortune to fence the edge of our 2.3 acres. What we are nearly settled on is wooden 4x4 posts with marine plywood screwed to both sides with one side perpendicular to the other in an alternating fashion.

There is an article by the Federal Highway Administration which refers to a "zig zag" pattern of fence, with a picture showing about a 20 degree angle of zigging and zagging with each section. Although it will add considerably to the total length, we do plan also to incorporate this into our fence. This apparently makes the structure far more wind resistant (something we need to consider) as well as more effective. And potentially less ugly. We also plan to plant some form of fast growing ivy or other vine to "de-uglify" the wall, and to assist in sound absorption. I am certainly looking forward to the day when it is complete! Also putting in a row or two of arborvitae should help a few years down the road.

Aside: We have a row of small trees, underbrush and vines, about 60 feet long and 20 feet deep on a portion of the area that faces the highway. Last Summer I wanted to "clean this area up," so I string trimmed it of its understory of brushy weeds and upper story of dense wild grape vines. The moment I turned off the trimmer, I regretted it. The visual improvement was not worth the greatly increased sound pouring through. Even though it does not extend the full length of the area, this boarder does seem to dull the noise when it is in full leaf. Who ever thought I would come to love a big stand of nettle, thistle, wild brambles and miscellaneous unidentified weeds, and some bent and broken trees infested with wild grape vines? It is October now, and to my regret, the leaves are falling and the weeds are dying. The noise has free run of the place again. Bah! Time to start digging those post holes!

Answer 2

Solid is better than not solid. Thicker is better than thinner.

But at the end of the day, wood fences won't do much to dampen sound at all.

If you can, go with a solid fence of some sort (block, brick, etc.) but that'd be expensive and laborious, of course.

If you have to stick with wood, go with solid panels and then plant a lot of shrubs on both sides of the fence. That might help over time. But don't invest in this thinking you will see sound dampening of all that much.

That said, it does appear there are some products on the market to help with this. I know nothing of these and are merely mentioning them as possible things to investigate:

• this looks like a sound deadening 'tarp' you attach to your fence: http://www.acoustiblok.com/acoustical_fence.php
• this one is a 'blanket' that attaches to the fence: http://www.acousticsblog.com/2014/reduce-unwanted-outdoor-noise-sound-blocking-fence/
• another idea I've seen is to string chicken wire between posts (both sides) and then fill the center with mulch. I like the idea, though dread the maintenance (as I think you'd have to refresh the mulch every few years.

Answer 3

If you've just moved in, give it a few months. Your brain will learn to filter out the noise better than the fence would. Unless you're setting up a sound studio, this is probably both simplest and most effective.

Answer 4

Moving would be the option most likely to actually work. Highway noise coming from a block away is probably not going to be significantly affected by a low fence, as it's already passed over/around a block worth of houses that are presumably taller than 8 feet.

Noise control "fences" (as built by the highway department where they build them) are massive and tall - either 6-8" thick solid wood, or concrete, and 20 feet tall.

Depending on the rules, you might try a berm (pile of dirt) and if the rules get confused by the ground level change that brings about, you might be able to stick 8 feet of something above that new ground level. Or not - depends on the rules, and who gets to interpret them.

Dirt, incidentally, works fairly well, to the extent that you can pile it, as it's quite massive.

A dense hedge may help, but if that's also considered a fence and stopped at 8 feet it's also limited.

Answer 5

The double board fence as you suggest may be your best chance at baffling the noise, whether it is a board and batten arrangement, or boards nailed relatively tight on either side of a purlin. Either of these are better than what you have now

What I believe will do you best at sound deadening, is planting ivy or other climbing vines to create depth on the face of the fence to help trap the sound. The vines can even be part of a vegetable garden.

Naturally this will take some time and the benefits may not be realized for a while to come. The downside of this is the vines will harbor moisture at the wood all the time and advance the decay of the wood. Do use pressure treated material for this problem, then do not use is for vegetable growing