noise reduction - thoughts?

[sian]

We have purchased a timber framed, 17th C house grade 2 listed, in Kent.
As we fell in love with the house we turned a
'blind ear' to the noise coming from a v. buisy main road. We are set slight ly down fom the road and have a v.lovely but very bare(in winter) beech hedge. In order to reduce the noise we are exploring:
1. Errecting a wooden fence ,keepin existing hedge and replanting verge side hedge 2. Secondry glazing which is tricky due to a number of gothic windows

We aren't looking at an either or solution, but do want to be realistic about what level of noise reduction we could achieve. Also shoukd we take on an acoustic surveyor and what sort of costs would this entail? Any bright ideas/words of wisdom?

 

[Penners]

Any bright ideas/words of wisdom?

Good grief, no. Not from me, anyway.

But here are a few amateur musings. If any experts on the subject disagree with me, then you should believe them, rather than me.

Sound attenuation is a very difficult subject to give advice on, sight unseen (or rather sound unheard). There are so many variable factors, and routes by which sound can travel, that really effective measures will definitely need expert, on-the-spot advice.

Sound travels in air. Yes, that's bloody obvious I know, but it means that wherever air can enter your building, so can noise. And the more that you can block, divert or slow down the movement of air, the more effect you will have on the noise. So thermal insulation (which also traps air) can be of some help in acoustic insulation, too.

However, mass is also important in attenuating sound. So, for example, a wall would probably be more effective than a fence - but I can't tell you by how much. Your hedge will have some effect - more in summer than in winter.

Secondary glazing will certainly be of some help, because there will be a wider layer of trapped air than there would be with sealed unit double glazing - this is good for sound insulation, prticularly if you can line the edges of the trapped air cavity with acoustic matting. But if your gothic windows are draughty, this will tend to reduce the effectiveness of the system, in terms of both thermal and acoustic insulation. So do as much draughtproofing as you can.

Something as simple as heavy curtains will make a significant difference, particularly combined with draughtproofing around windows and doors. And with a timberframe house, look out also for things like shrinkage gaps between the beams and the infill. If you have suspended ground floors with air bricks to ventilate the underfloor space, make sure there are no gaps around the edges of the floors.

And so on and so on.... there are lots of things you can do, some of which will have a small effect, some a larger effect. You'll just have to decide on an order of priority and what you can afford.

But I repeat - expert advice after a proper inspection of the house is the only really reliable way to proceed.

One final thought - remember that some of the above suggestions will require LBC. The fence/wall, for example, ditto the secondary glazing.

 

[biffvernon]

If you are putting in secondary glazing consider using laminated glass, preferably with the two layers different thicknesses, say 3 mm and 4 mm and choose the thicker alternative for the plastic layer in the middle.

 

[skier-hughes]

Also consider adding to the hedge with something like holly an evergreen?