Our rural house is located 200 yards from an interstate highway overpass. House is parralel to interstate, and overpass is located near a corner of property. How can we reduce the noise entering the yard?
Specifics:
- Most of the noise comes from the beneath overpass
- Eucalyptus and oak trees block about 40% visibility of the interstate
- No fencing exists between interstate and house
- Exterior wall facing the interstate reflects noise back into the yard
- Nearest neighbor is 300 yards away
- House is very quiet inside, but yard is very loud
My own ideas:
- Build up 6' berm of dirt on edge of property, close to interstate, and erect
an 8'a 7' wooden fence on top of that - Plant a row of oleander close to interstate
- Build a fence that completely blocks visibility of overpass
Another concern:
- If a fence is recommended, should it be located closer to interstate, or closer to house?
Best Answer
If you go with trees, go with spruce: This gives you high density twig/leaf structure. Evergreen leaf trees are also possibles.
Trees don't reduce sound by a lot, factor of 2 to 4. That sounds like a lot, but it's only 3 to 6 db. 3 db is just detectable. An earth berm is the best system. Make it fairly steep on the side facing the noise so that sound is reflected up. However, trees generate their own noise -- closer to white noise without the swoosh of traffic. This will help mask the freeway noise.
Material for a berm can come from creating a pond. A track hoe here in Canada runs about 1500 bucks a day, and a day's work moves a LOT of earth.
If you are going to build a wall, it needs to be massive. Stone, concrete, brick, block. Ideally such a wall has a hollow core, with the area density different on either side of the core. This reduces coupling between the front wall and the back wall.