Building question...

[ledger]

I have recently moved to a 1930's detached house. The road it is on, although not busy seems to create a diproportionate amount of noise for each car that passes. I am not sure if this is due to the road surface or that fact that we are at the very bottom of a steep valley.

Anway, each of the upstairs room has a vent in the wall, basically a big hole with a brick on the outside wall with several(6-8) holes in. These seem to let in a lot of noise. I presume that these were originally for ventilation and maybe to reduce condensation. My question is can I block these up to reduce noise as the house is fitted with central heating. ?

thanks

[westy04]

No
You will cause damp. The house needs ventilation to breath.

[b17nns]

Our home is new build (3 years old) and it has a vent either side of the gas fire. When we had the fire installed the fitter who was Corgi registered said that as long as the fire and flue are functioning correctly then there is no need for them.

The amusing part is that our house is extreemly well insulated, has double glazing and all the mod cons to meet current building regulations but then they force the builder to put 2 gaping holes in the lounge.

[ledger]

but how much ventialtion does a house need and how would I find out ?. Does it really need a vent in every room except the bathroom ?.

For example my mothers house, although 70's built has no vents except for a small one in the replacement double glazing which is apparently for the central heating.

Any ideas on how to reduce the noise form these vents whilst leaving then in situ ?.

thanks

[parrot of doom]

You cannot block these holes. They are air bricks. Without them, you will get damp.

Central heating will not stop damp. If anything, it will increase it. Damp has little to do with how warm the house is, and everything to do with how moist the air is.

Your house must be allowed to ventilate properly. Under no circumstances block these vents.

The noise coming through these vents will be mainly high frequency noise. This can be reduced by using baffles. What I suggest you consider is placing baffles on the external walls outside the vents. These will not stop the air bricks from doing their job, although they will reduce circulation very slightly. You could make your own if you're so inclined, its like a small foot stool placed on its side, 4 legs, each leg on each corner of the airbrick. Thus sound cannot directly enter the airbrick vents, it has to come in from the sides of the baffle, which will reduce the noise level somewhat.

The rest of the traffic noise will be low frequency rumble, which you can basically do nothing about.

[parrot of doom]

www.greenwood.co.uk/data/GW%20Airbrick%20data%20sheet.pdf

Take a look at those. You can paint them to disguise the visual effect.

[parrot of doom]

Oh, can you provide a picture from your house to the road? Is there any shrubbery between your garden and the road? Is there a wall on the other side of the road from your house, reflecting the noise?

[mrmaggit]

Have a look at Stadium "Black Hole" vents. These come as a complete set with baffles, or you could cover the vents on the inside with "Hit and Miss" vents, which have a sliding closer on them, together with a flyscreen.
Black holes are about £20 plus VAT, H&M's are about £1.60 plus VAT

[ledger]

parrot of doom said:

Oh, can you provide a picture from your house to the road? Is there any shrubbery between your garden and the road? Is there a wall on the other side of the road from your house, reflecting the noise?

I can post a picture up tomorrow.

there is some shrubbery between the house and the road, but it's not particularly large.

both sides of the road is lined with large houses that are only set aback about 30 feet.

The noise I can hear is mainly low frequency

[parrot of doom]

You can do nothing about LF noise (ie less than 1000Hz), most of it is carried through the ground and into your property.

Airbourne noise (tyre roar, engines etc) will need the types of baffles I linked above.

[rsvmilly]

If you've got trickle vents in your windows you can block these other vents up.

[ledger]

parrot of doom said:

Airbourne noise (tyre roar, engines etc) will need the types of baffles I linked above.

sorry this was the kind of noise that I meant.

a factor may be that there is no other noise, so when a car passes it is really noticable.

[deeen]

Have you got cavity walls? If not, you might as well block the vents up. If you have, do you have cavity wall insulation? If so, you might as well block the vents up - the insulation stops them functioning as intended anyway. Is the top of the cavity open, in the loft, under the eaves? If so, if it was my house I would be happy blocking off the first floor vents, but would want to make sure the vents near ground level were clear. If the top of the cavity is closed, I would consider venting there and closing the vents on the front of the house.

Finally, back to your original problem, how are your windows? I have visited houses where I could put a piece of paper between the window frame and the brickwork, and pull it through. It only takes a tiny gap to transmit noise. If all is sound, try secondary glazing on the front of the house, secondary with a big air gap is good for sound insulation, better than it is at heat insulation, in fact.

[ledger]

deeen said:

Have you got cavity walls?

don't think so, but not sure how do I tell

deeen said:

Finally, back to your original problem, how are your windows?

I think that al is sound with the windows as the front of the house and you can hear a significant difference when you open one of the small windows (30cm x 15cm).

deeen said:

If all is sound, try secondary glazing on the front of the house, secondary with a big air gap is good for sound insulation, better than it is at heat insulation, in fact.

I did consider this, but the windows at the front of the house are quite large so I was wandering how practical unsightly this would be.

The vent I have examined was basically an empty void with a very ill fitting interior grill. Could I pack the void with some sound deadening material that would still allowed air circulation i.e. mineral wool ?. Presumable fitting a closeable interior grill and bonding it's perimeter to the wall would probably help.

[rsvmilly]

Is there a fireplace in the rooms with these vents? If so, their purpose is to let in fresh air, to replace the air that is sucked out by the chimney (passive stack effect).

You can get accoustic wall vents. Further reading;

www.passivent.com/pd_index.html

And a good indication that you have cavity walls is that the total thickness will be at least 250mm.

[ledger]

rsvmilly said:

Is there a fireplace in the rooms with these vents? If so, their purpose is to let in fresh air, to replace the air that is sucked out by the chimney (passive stack effect).

there is a chinmey on each side of the house, but I there is only one firplace. When I redecoarate the bedrooms I will be looking to see if any fireplaces have been boarded up.

[deeen]

ledger said:

[quote=deeen]Have you got cavity walls?

don't think so, but not sure how do I tell

Take off or open the vent in the room. Look / feel inside. If you find brick wall, gap, then outer brick wall, that is a cavity wall (the "gap" is the cavity)

The more I think about a 1930's council house, the more I think every main room may have had a fireplace, and the more I think this is a room vent, in which case you can block it up as long as there is no open or gas fire in the room.

Secondary glazing is very unobtrusive from outside, however can be quite unsightly from inside, and sometimes restricts how useable the window openings are.

If you don't have a fire (gas or open) in the room, I would block up the vent and see how you get on with the noise then, if it was my house.

[Melv]

Replace them with Passivents initially.

Won't be any harm in the future if you block them up and control ventilation manually -i.e. opening and closing windows!!

E me direct if any specific queries.

And see: www.firsthurdle.com/drdamp

Rgds
Mel
aka Dr. Damp
'Trust Me'

[dilbert]

At least it's not Mr Mildly Moist!
Sorry

>> Edited by dilbert on Thursday 3rd March 15:10

[ledger]

Melv said:

Replace them with Passivents initially. Won't be any harm in the future if you block them up and control ventilation manually -i.e. opening and closing windows!! E me direct if any specific queries. And see: www.firsthurdle.com/drdamp Rgds Mel aka Dr. Damp 'Trust Me'

thanks Melv.

Will the Passivents help with the noise problem ?.

why not block the vents up straight away ?.