Page 1 of 2
Posted: Mon Mar 19, 2007 1:58 pm
by t5nel
Hi newbie posting so bear with me...
Seems that this is the right forum to post in and thatthere is a wealth of knowledge here so...here goes.
I am moving into a new house that backs onto a busy (although not main) road.
The back of the garden is about 2m from the road with the house a further 22 m away. The noise in the house is OK but in the garden it is a bit of an annoyance. I have looked into wooden 'acoustic' refelctive fencing as a means to try ad reduce the noise in the garden.
It is not cheap (£100/m - £170/m) for 2.4m height. From doing some research it seems that sll these things do is bounce the sound back away from the garden. In order for them to be effective they need to be as high as possible, have no holes/gaps and be heavy/solid. SO basically they are tall heavy wooden fences with all the joints covered over with more timber.
Having seeked some advice I was pointed towards the idea of a wall instead. It will clearly be better at reducing noise (according to the boffins) and should last better than a wood fence.
I am very interested in knowing
1)Has anyone built a wall where one of the aims was to reduce noise the other side of it? Was the customer happy?
2)What sort of height is sensible to achieve? In terms of planning permission, wind loading etc.
3)What options are there for materials - I would love brick but imagine that two faced wall would cost loads. I think plain gray block wall would not go down well so are there attractive concrete blocks? Or is there any sort of render that would not need constant repainting?
4)What sort of costs and time would I be looking at (per metre) for a 2.4m wall? The wall will need to be 25-30m long and will go round one corner, site access is pretty good. House is in Berkshire
5)How do I go about designing this beast?
Thanks in advance
Tim
Posted: Mon Mar 19, 2007 4:45 pm
by Mark B
Tim,
Regarding point number 5, there is a render available known as "k-rend" see there website http://www.k-rend.co.uk/flash.htm for more info. the supply some really good renders for different purposes, they come pre coloured and hav a great looking finish with consistant colour also meaning little or no painting in its lifetime on the wall.
mark
Posted: Mon Mar 19, 2007 4:46 pm
by Tony McC
1 - yes, but not 100% success. Customer not happy, but then again, she never was, and wouldn't have been even if I'd built the damned thing for nowt and paid for her to cruise the Med while the building work was ongoing.
2 - 2m min. Owt higher *must* be designed by a structural engineer (as was the one we built in Prestwich) and must be approved by the local BCO. However, the higher: the better, apparently.
3 - We used CMU (dense blocks) with a skim render and then a sort of wooden baffle panel that was nowt more than lengths of 100x19 treated softwood fixed vertically to horiziontal batten to create a 25mm gap between panel and wall. This was supposed to deaden any noise before it got to the wall according the the struct.eng. (my arse!)
4 - I'm way out of touch with prices for walling, but I'd guess it'd be somewhere close to 100 quid per m² and 10-15m² per day
5 - you don't. You have to get a structural engineer. 
Posted: Mon Mar 19, 2007 5:07 pm
by dig dug dan
I once constructed a wooden barrier fence for a customer, and they looked at the buffallo fencing(the sort you see along motorways), and it was an arm and a leg. the spec for the post holes meant each one took half a metre of concrete!
We designed our own, and it was simple, and the customer says it is quite effective.
All it entailed was some specially morticed posts that enabled a 4x2 to be used as a rail instead of an arriss, and then BOTH sides were clad in fetheredge. This gave a two inch gap between the inner and outer edge, and the sound was "reverberated" in side this gap, and significantly reduced.
We only built it to 2m high due to planning regs, but it was certainly a lot cheaper than a wall!
Posted: Mon Mar 19, 2007 5:16 pm
by t5nel
Thanks for the replies chaps, nice to know that some people give a damn to help others out AND know their potatoes!
Tony, the wall sounds interesting, I can't see how the wood would help 'deaden' the sound...the only stuff that really absorbs would be rockwool etc. I think the principle is always big, heavy, solid, no air gaps and high as possible. I expect stacking prefab concrete fencing up to 3m would be very effective but also very ugly!
Would a structural engineer cost £000's, I would imagine they bang these out to a template if they know the local soil conditions and wind loads etc...
However I think the cost would be too much as if it is £250/m approx then it would cost a fortune!
Thanks
Tim
Posted: Mon Mar 19, 2007 5:26 pm
by t5nel
dig dug dan,
That sounds interesting.
I have seen buffalo, also jacksons fencing do one and betta fencing. They all do the commercial stuff mainly and charge to suit company budgets!!!
Any ideas how suitable a tongue and groove fence would be and also any decent suppliers near to Berkshire?? THis sort of fence should be quite airtight.
As an alternative, I had thought about sticking boards onto the back of good quality closeboard panels. This would make a fairly quick way to build the two faced fence. I guess the finishing rail on top of the fence would need to be replace with a wider one but that is not the end of the world
However I still have no idea how well this works in a garden and not on a motorway. I am hoping for a noticeable drop - at the moment one side only has chainlink fence and you can see the cars so this should make quite a difference.
Thanks
Tim
Posted: Mon Mar 19, 2007 9:58 pm
by lutonlagerlout
i am not 100 % on this but could this be 1 situation were leylandii hedging might be appropriate?
i did some walls for a sound studio and we had to build 2 walls in concrete blocks 150 mm apart then fill the gap with sand,not cheap but they needed proper quiet
cheers LLL 
Posted: Tue Mar 20, 2007 12:21 am
by Suggers
Acoustically, the only thing that stops sound is mass - always expensive.
Don't wanna be too much of a downer, but you'll need planning for anything over a metre high - adjacent to the highway. (the missus is a planner :O )
Here's the relevant General Permitted Development Order excerpt
Permitted development
A. The erection, construction, maintenance, improvement or alteration of a gate, fence, wall or other means of enclosure.
Development not permitted
A.1 Development is not permitted by Class A if—
(a) the height of any gate, fence, wall or means of enclosure erected or constructed adjacent to a highway used by vehicular traffic would, after the carrying out of the development, exceed one metre above ground level;
(b) the height of any other gate, fence, wall or means of enclosure erected or constructed would exceed two metres above ground level;
© the height of any gate, fence, wall or other means of enclosure maintained, improved or altered would, as a result of the development, exceed its former height or the height referred to in sub-paragraph (a) or (b) as the height appropriate to it if erected or constructed, whichever is the greater; or
(d) it would involve development within the curtilage of, or to a gate, fence, wall or other means of enclosure surrounding, a listed building.
I'm gonna join The Plain English Society !! - all the best.
Posted: Tue Mar 20, 2007 7:03 pm
by Ted
Could you affix soundbloc plasterboard to a concrete block wall and then put a waterproof render on to it?
Just an idea!
Posted: Tue Mar 20, 2007 7:16 pm
by Ted
You could also texture any render. Would that deaden the sound a little?
Posted: Tue Mar 20, 2007 9:00 pm
by lutonlagerlout
how about a vanity unit ted?
PMSL
LLL 
Posted: Tue Mar 20, 2007 9:10 pm
by Ted
lutonlagerlout wrote:how about a vanity unit ted?
PMSL
LLL
Which of my suggestions are you laughing at?
The texture or the plasterboard?
Posted: Wed Mar 21, 2007 12:22 am
by lutonlagerlout
jk m8 i was talking about that sink you made for the arki-tect
that was rendered wasn't it?
regards LLL
Posted: Wed Mar 21, 2007 12:36 am
by Ted
Ahh! It was rendered, yes.
Another idea is that if you put an overhang on the wall that might curb the noise from travelling up and over the wall?
But I am no acoustics man or sound techie person...
Posted: Wed Mar 21, 2007 12:40 am
by Suggers
The sink/basin was fantastic....
Ted should be set-building on movies - would make a fortune.