Dripping noise coming from inside the house when it rains

dantheman2010

Hi guys

When it rains, I seem to have a single dripping sound coming from what seems to be the extractor fan cavity for the extractor fan over the hob.

At first I thought it was because there was a slat missing from the extractor fan vent cover on the outside of the house, so I replaced this but has made no difference.

The sound is very loud in the kitchen, not so loud in the bedroom above and again not so loud in the loft above of that bedroom.

When it rains I have been outside and I can hear the drip of water but cannot see where it is dripping, but it is much louder inside that outside. It sounds like a single drop of water dripping from a tap into a metal sink (to give a sort of description).

I have looked at my roof from the back of my garden and cant see any tiles missing, I have been into the loft into the corner where I think the sound is coming from but cant see any leaks.

I am not too sure whether it is coming from the roof through a hole into the cavity wall.

Lost for ideas, I have a plumber who has said for me to get him to come round when its next raining and hear the noise and see if he can see anything.

I have looked around the forums and not found anyone with the same or similar problems.

I would leave it if it wasnt for two things;

One I dont want lasting damage caused
Two its very annoying at night time

But as I said this only happens when it rains!

I thank you for your help.

dantheman2010

Hi guys, just wondering if anyone can help.

I have just taken the vent off on the exterior wall, I can see no signs of water, but thats because it hasnt rained here since last Saturday (when the noise was last heard), however I think it must be water running off the roof of the house next door (the end terrace house) whose roof is a higher, falling on to mine and there must be a small hole or something up there that is letting a small trickle of water fall all the way down from the roof (inside the outer wall and cavity wall) and just hit the top of the extractor fan vent. If I tap the vent pipe with my finger it makes a similar but louder noise than it does when it rains - the sound of the rain drop must echo along the pipe and wall to make it sound so loud.

I can see nor feel any moisture in the pipe and I can see damp or damage from within the house but wondered if anyone had any thoughts or advice.

Thanks

missile

If you can access the exterior of the pipe(?) you could spray polyurethane foam which would reduce / eliminate the sound.

Small leaks can be difficult to locate but they can cause serious damage to your property. I would get a slater to examine the flashing between you and next door property.

Could it be dripping onto this pipe where it exits your wall?

CLAPTON

where is the outlet for the extractor fan?
is it easility reachable
can you seal it up temporarialy when it rains to see if this is the cause?

could the noise come from an unused chimney?

ormus

stick a bit of rubber on the top of the vent casing then.
silence.

dantheman2010

Hi all, I think I have narrowed it to 2 possible causes, either the guttering is clogged and a small drop is over flowing and spilling on the plastic extractor fan vent on the wall and echoing in to the pipe OR there is a problem with a roof tile and a drip is falling inbetween the cavity wall and external wall and tapping the pipe.

I managed to touch the top of the pipe and like I said it is not wet or even damp. However I have left the vent off for now, so next time it rains if I dont hear the noise then I guess I will need to clean the gutters out and if I do hear the noise then cause number 1 is ruled out and I will have to check to see if the pipe is wet/damp and like you say get a roofer out to have a look.

Ormus, when you say a piece of rubber, what would you suggest? The gap between the outer wall (where the vent is/was stuck to the wall) and the top of the pipe is very small, I can only just fit my fingers through, so not sure what I could get to fit in there.

Thanks guys.

missile

dantheman2010 wrote: »

... The gap between the outer wall (where the vent is/was stuck to the wall) and the top of the pipe is very small, I can only just fit my fingers through, so not sure what I could get to fit in there..

That is why I suggested polyurethane foam. It comes in an aerosol can with a nozzle so you could spray into a small crack http://www.google.co.uk/products/catalog?hl=en&q=expanding+foam&um=1&ie=UTF-8&cid=10835526456887625441&ei=JAEETe6fDNSChQej8sHuBw&sa=X&oi=product_catalog_result&ct=result&resnum=1&ved=0CDEQ8wIwAA#

dantheman2010

So I would basically just spray some on top of the plastic pipe to dampen the sound and lessen the echo?

ormus

unless ive got it wrong. this is how i see it.
cut a bit of scrap rubber (as shown) to fit and then stick it place. along the top edge.

am i anywhere near?

dantheman2010

Ok thank you, the pic didnt show, but thanks for the suggestion.

dantheman2010

On Sunday I taped a bit of kitchen towel to the top of the pipe (inside the wall) so I would be able to tell if water was dripping on to it.

I just went home to check as it has rained for the first time in a while and the kitchen towel is soaking.

There is no way the rain could have blown into the wall with the vent off because the inside of the extractor fan pipe/tube is not wet and that is what is exposed to the elements the most. The only way to touch the top is to squeeze my fingers between the gap at the top of the vent opening and top of the pipe.

The kitchen towel was drenched. The roof tile which is located directly above the vent opening seems to be sitting about an inch or two higher than the rest of the tiles on the roof.

I am convinced that there is either a hole in the felt underneath the tile that isnt sitting right or there is an accumulation of water sitting on the felt that when it rains and puts more water into the accumulation and lets small drops drip through down on to the pipe sitting in the gap between the outer and cavity wall.

If it wasnt for the drip on the pipe making a noise I would be none the wiser, I have a plumber coming round to sort out some other bits and pieces around the house and is going to have a look up there and see whats what.

In the mean time I wondered if anyone else has any suggestions.

Thank you.