# Very loud vibration/drilling type noise in roofspace after water has been used



## Caveat (30 Oct 2008)

Just happened this morning after I turned the shower off (shower is direct from bath taps) - I actually though it was drilling or other machinery at a site across the road.

The sound continued for about 20 seconds then stopped abruptly. 

I turned on both sink taps for a couple of minutes and it happened again.

Only seems to happen once the water is off.

Any ideas?


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## daithi28 (30 Oct 2008)

Do you a water pump pumping water into the watertank in the attic becasue of low water pressure in your area? Maybe it's on its last legs?


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## Caveat (30 Oct 2008)

daithi28 said:


> Do you a water pump pumping water into the watertank in the attic becasue of low water pressure in your area? Maybe it's on its last legs?


 
Thanks - no idea really - if we do have a pump, where exactly would it be and what should I check do you know?


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## wheeler (30 Oct 2008)

Was anyone doing any work in your attic recently? Or around the boiler?


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## declanja (30 Oct 2008)

I'm no expert but I had a similar problem once. Turns out there was grit in the system (following mains supply repairs by Co Co)and had become jammed in the ballcock in the water tank. Solved by replacing the washer in the ballcock. Hope this works.


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## mathepac (30 Oct 2008)

Sounds to me like "water-knock", vibration caused in pipes when water flows through pipes that are not properly secured. This can weaken joints over time and cause leaks. Either that or an air-lock somewhere.


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## Caveat (30 Oct 2008)

Thanks all - no work done recently BTW.

I'd thought of water knock but had always thought of that as being a fairly distinctive knocking/clanging.

This is different though - if it is water knock, the 'knocks' are very rapid so much so that as I said, it literally sounds like someone drilling in the roofspace. I'll check to see if the pipes are secure anyway.

So if it's an airlock what so I need to do?


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## Sherman (30 Oct 2008)

Sounds like it could be water hammer.


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## DavyJones (30 Oct 2008)

If it is just a recent thing it may be worth taking ballcock apart as suggested. the ballcock has a small hole that lets water pass through and can be easily blocked by grit etc.

turn off mains.

find ballcock in attic and you will see a 3/4" nut just inside the tank. This nut holds the body of the ballcock to the stem. 

support the body of the ballcock with a spanner/grips and turn nut, it may take some muscle.

when you loosen nut and seperate valve be sure and point the body (part with arm and float) down as this is where all the parts are held and if they fall out you will be messing around and trying to figure how they go back in.

you should now see a red or white orifice, remove it and unblock it.

 Take note of how it came out as it has to be put back exactly the same way.


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## Caveat (31 Oct 2008)

Thanks again - I'll have a look over the weekend and see what I find.


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