Porcupine Posted May 8, 2021 Report Share Posted May 8, 2021 Hi all, My lovely narrowboat leaks when it rains hard. What’s strange is there is no particular spot it comes in. It’s an elusive leak that chooses where it pops up. There aren’t any holes in the roof. I think it must be coming through the mushroom vents? Any ideas how I can stop this phantom leak? Thanks, Matt Link to comment Share on other sites More sharing options...
mrsmelly Posted May 8, 2021 Report Share Posted May 8, 2021 As you say its likely to be from a vent and running anywhere the boat is leaning at any specific time. Remove vents and seal is the only way realy. Link to comment Share on other sites More sharing options...
blackrose Posted May 8, 2021 Report Share Posted May 8, 2021 (edited) Yes, when you get some dry weather remove the vents, clean up both faces and reseal them. Make sure the screw threads are sealed too. This is the stuff to use - comes in black, white and clear. https://www.toolstation.com/stixall-adhesive-sealant/p60981 Edited May 8, 2021 by blackrose Link to comment Share on other sites More sharing options...
Tracy D'arth Posted May 8, 2021 Report Share Posted May 8, 2021 Condensation on the roof steel, bad insulation and no vapour barrier. Link to comment Share on other sites More sharing options...
Tony Brooks Posted May 8, 2021 Report Share Posted May 8, 2021 The OP has not explained what they mean by leaks. In heavy driving rain water drops can bounce up off the roof and into a mushroom vent and I have had similar through flying saucer vents. So @Porcupine are you talking about water dripping from the roof, water drops dropping though the vent or water gathering in the bilge. Link to comment Share on other sites More sharing options...
blackrose Posted May 8, 2021 Report Share Posted May 8, 2021 32 minutes ago, Tracy D'arth said: Condensation on the roof steel, bad insulation and no vapour barrier. When it rains hard? 1 Link to comment Share on other sites More sharing options...
cheshire~rose Posted May 8, 2021 Report Share Posted May 8, 2021 Leaks can be elusive! Water will always tend to flow downhill but that can vary depending were it gets in and what the trim of the boat is like. We had a drip under our side hatch. We were aware that one porthole forward of the side hatch was also needing to be resealed but we couldn't work out where the water was getting in around the side hatch. When the boat was painted the ports came out and it turned out that the bond between front and back face of the brass had broken. It would never have been spotted if he porthole had not been removed. It was rebonded and sealed back in place and.... yes - Voila! that fixed the drip by the side hatch too! Link to comment Share on other sites More sharing options...
ditchcrawler Posted May 8, 2021 Report Share Posted May 8, 2021 Steel top or wood or glass fibre top? Link to comment Share on other sites More sharing options...
Porcupine Posted May 8, 2021 Author Report Share Posted May 8, 2021 Thanks very much, I will definitely reseal all the vents. I also wonder if I should do the same with the solar panel and their connections too. Matt Hi Tony, Very heavy rain is dripping through the vents - but my real problem is drips leaking through the ceiling. Matt Link to comment Share on other sites More sharing options...
David Mack Posted May 8, 2021 Report Share Posted May 8, 2021 34 minutes ago, Porcupine said: Very heavy rain is dripping through the vents - but my real problem is drips leaking through the ceiling. Could it be that some of the water which comes through the vents drops straight down, and some of it leaks into the space between the roof and the ceiling lining, then flows across the top of the lining to leak out somewhere else? Link to comment Share on other sites More sharing options...
Tony Brooks Posted May 8, 2021 Report Share Posted May 8, 2021 5 minutes ago, David Mack said: Could it be that some of the water which comes through the vents drops straight down, and some of it leaks into the space between the roof and the ceiling lining, then flows across the top of the lining to leak out somewhere else? Well until the OP decides to tell us more we can't even guess. I note my questions have been ignored/ Link to comment Share on other sites More sharing options...
ditchcrawler Posted May 8, 2021 Report Share Posted May 8, 2021 Are they mushroom vents or flying saucer type ones? Link to comment Share on other sites More sharing options...
Sir Percy Posted May 8, 2021 Report Share Posted May 8, 2021 24 minutes ago, ditchcrawler said: Are they mushroom vents or flying saucer type ones? He's mentioned mushroom vents. Link to comment Share on other sites More sharing options...
ditchcrawler Posted May 8, 2021 Report Share Posted May 8, 2021 1 minute ago, Sir Percy said: He's mentioned mushroom vents. Missed that, Its surprising how much water will wick in if there is rust between the base of the vent and the steel roof. I had it on an engine room hatch and it was a bucket job when it rained and it flowed uphill Link to comment Share on other sites More sharing options...
Sir Percy Posted May 8, 2021 Report Share Posted May 8, 2021 5 minutes ago, ditchcrawler said: Missed that, Its surprising how much water will wick in if there is rust between the base of the vent and the steel roof. I had it on an engine room hatch and it was a bucket job when it rained and it flowed uphill He's also said that he's going to re-seal the vents, so that should take care of the most likely point of entry. If its a case of rain bouncing up and in during a heavy downpour, I guess he could screw down the cap as far as poss? Link to comment Share on other sites More sharing options...
Richard10002 Posted May 9, 2021 Report Share Posted May 9, 2021 I have wondered if I had fitted my solar panels over the mushroom vents it both would stop the bounce back of heavy rain, and be safe in terms of airflow. I only get occasional small amounts of rain bouncing in, so it’s not been an issue that needed dealing with. Link to comment Share on other sites More sharing options...
Porcupine Posted May 9, 2021 Author Report Share Posted May 9, 2021 Thanks everyone, I have tightened my mushroom vents which were actually quite open. Hope this fixes the problem. Otherwise I will try sealant. Thanks all, Matt Link to comment Share on other sites More sharing options...
Tony Brooks Posted May 9, 2021 Report Share Posted May 9, 2021 Just now, Porcupine said: Thanks everyone, I have tightened my mushroom vents which were actually quite open. Hope this fixes the problem. Otherwise I will try sealant. Thanks all, Matt Perhaps you might explain why when you originally posted a very poorly defined question that could have a myriad of answers you refused to answer the questions I posed to try to get you the most likely answer. I don't expect boaters to know what may be important and what is not but if they want help I do expect them to provide what is needed to get a sensible answer. The reason I ask is that a refusal to answer questions seem to be getting more and more common and if a fault can't be narrowed down the boater will get loads of answers, many of which will not be the right ones. Any way I hope that you have solved the problem. Link to comment Share on other sites More sharing options...
Porcupine Posted May 9, 2021 Author Report Share Posted May 9, 2021 Thanks Tony, I will bare that in mind in the future Link to comment Share on other sites More sharing options...
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