jddevel Posted March 22, 2017 Report Share Posted March 22, 2017 I know we`ve had some driving rain recently so is it common to find water has entered via the mushroom vents . Or is it due to the type of vents the hull manufacturers fitted please. They are the "mushroom" type. Link to comment Share on other sites More sharing options...
cereal tiller Posted March 22, 2017 Report Share Posted March 22, 2017 8 minutes ago, jddevel said: I know we`ve had some driving rain recently so is it common to find water has entered via the mushroom vents . Or is it due to the type of vents the hull manufacturers fitted please. They are the "mushroom" type. How tall is the Upstand(fixed bit),my current ones have a 45 mm Up stand and don't allow Rain to bounce up to the inside of the top and drip into the Boat The shallower versions(25-35 mm )do leak when Rain is heavy Link to comment Share on other sites More sharing options...
Neil Smith Posted March 22, 2017 Report Share Posted March 22, 2017 You could wind them down a bit to stop rain bouncing up into them, or put a bowl over them. neil Link to comment Share on other sites More sharing options...
mrsmelly Posted March 22, 2017 Report Share Posted March 22, 2017 2 hours ago, jddevel said: I know we`ve had some driving rain recently so is it common to find water has entered via the mushroom vents . Or is it due to the type of vents the hull manufacturers fitted please. They are the "mushroom" type. Yes it happens periodically in very heavy downpours. Link to comment Share on other sites More sharing options...
bizzard Posted March 22, 2017 Report Share Posted March 22, 2017 Fix umbrellas over them. Link to comment Share on other sites More sharing options...
Neil Smith Posted March 22, 2017 Report Share Posted March 22, 2017 15 minutes ago, bizzard said: Fix umbrellas over them. Or under them so you keep dry. Neil 1 Link to comment Share on other sites More sharing options...
Machpoint005 Posted March 22, 2017 Report Share Posted March 22, 2017 3 hours ago, jddevel said: I know we`ve had some driving rain recently so is it common to find water has entered via the mushroom vents . Or is it due to the type of vents the hull manufacturers fitted please. They are the "mushroom" type. Yes, it is. (Don't ask me how I know!) Link to comment Share on other sites More sharing options...
jddevel Posted March 22, 2017 Author Report Share Posted March 22, 2017 Did not realize you can wind them down they certainly seem tall enough, however there does appear quite a gap between the upstand and the "lid". Will turn them down a bit. Thank you. Link to comment Share on other sites More sharing options...
Neil2 Posted March 22, 2017 Report Share Posted March 22, 2017 Considering the design of mushroom vents is supposed to stop surface water getting in I would say no it is not common but we can only speak from our own experience. I've only ever had water getting past them when the seal has failed. Quite a few people do seem to suffer from condensation in these vents (usually when there's a vent over the bed..) which can confuse the issue. Link to comment Share on other sites More sharing options...
Jen-in-Wellies Posted March 23, 2017 Report Share Posted March 23, 2017 Hail stones bounce up from the roof and drop through mushroom vents very easily! Jen Link to comment Share on other sites More sharing options...
Neil2 Posted March 23, 2017 Report Share Posted March 23, 2017 1 hour ago, Jen-in-Wellies said: Hail stones bounce up from the roof and drop through mushroom vents very easily! Jen Nope, that's never happened to me, our vents are 100% watertight. Maybe I've got, ahem, magic mushroom vents. 1 Link to comment Share on other sites More sharing options...
Neil Smith Posted March 23, 2017 Report Share Posted March 23, 2017 If you set them so the bottom of the mushroom rim is below the upstand they should be watertight. Neil Link to comment Share on other sites More sharing options...
system 4-50 Posted March 23, 2017 Report Share Posted March 23, 2017 I've got a leaky UFO. I thought that was impossible. I'll have to take it apart and see what is going on. It is on the centre line of the roof as well! Link to comment Share on other sites More sharing options...
mross Posted March 23, 2017 Report Share Posted March 23, 2017 On a hot day, I unscrew them all the way, so that the rim is above the upstand; this allows warm air from the boat to escape. When I'm cold, I screw them down and this helps trap warm air in the mushroom. This also keeps the rain out. Link to comment Share on other sites More sharing options...
DHutch Posted March 23, 2017 Report Share Posted March 23, 2017 This is not unknown, and certainly while we find the issue very manageable, i would always advise a user fit them over the corridor/bath or similar rather than over a bed or cupboard. - As said, some are better designed than others. Also be aware that some allow you to full close them, which causes issues for the BSS (now 'only' recommended) ventilation requirements unless you modify them by placing a nut or similar over the thread to limit travel. Daniel Link to comment Share on other sites More sharing options...
Neil2 Posted March 23, 2017 Report Share Posted March 23, 2017 4 hours ago, system 4-50 said: I've got a leaky UFO. I thought that was impossible. I'll have to take it apart and see what is going on. It is on the centre line of the roof as well! I've had leaky flying saucer vents I think it was something to do with the rubber gasket thingy. As you say the design implies they can't leak but in my experience there's no orifice on a narrowboat that won't leak given time. Link to comment Share on other sites More sharing options...
Dave Payne Posted March 23, 2017 Report Share Posted March 23, 2017 replaced my ufo type vents this year, horrible things that require stripping and cleaning on top of sealing each year. Link to comment Share on other sites More sharing options...
jddevel Posted March 23, 2017 Author Report Share Posted March 23, 2017 "On a hot day, I unscrew them all the way, so that the rim is above the upstand; this allows warm air from the boat to escape. When I'm cold, I screw them down and this helps trap warm air in the mushroom. This also keeps the rain out. " Now that sounds like a business opportunity in some of the wealthier areas either a manually altered one carried out by marina staff or obliging other boat owners-for a small fee. Or perhaps design electrically operated ones. Mmm or perhaps thermostatically/humidity reactive. Could even operate via a smart phone. Oh I better stop I don`t know what I`m talking about and too much else to worry about. Link to comment Share on other sites More sharing options...
ditchcrawler Posted March 23, 2017 Report Share Posted March 23, 2017 1 minute ago, jddevel said: "On a hot day, I unscrew them all the way, so that the rim is above the upstand; this allows warm air from the boat to escape. When I'm cold, I screw them down and this helps trap warm air in the mushroom. This also keeps the rain out. " Now that sounds like a business opportunity in some of the wealthier areas either a manually altered one carried out by marina staff or obliging other boat owners-for a small fee. Or perhaps design electrically operated ones. Mmm or perhaps thermostatically/humidity reactive. Could even operate via a smart phone. Oh I better stop I don`t know what I`m talking about and too much else to worry about. Or just use the boat and turn the know with your hand. Link to comment Share on other sites More sharing options...
alan_fincher Posted March 23, 2017 Report Share Posted March 23, 2017 On 22/03/2017 at 13:39, cereal tiller said: How tall is the Upstand(fixed bit),my current ones have a 45 mm Up stand and don't allow Rain to bounce up to the inside of the top and drip into the Boat The shallower versions(25-35 mm )do leak when Rain is heavy This very sensible response seems to have been ignored in almost every post that has followed it. This is the key. If the upstanding sides of the lower part are shallow, (say an inch or less), then very heavy rain will bounce off the roof hard enough that it the gets up under the covering dome, and can fall down inside that upstand. This can happen even of the dome is screwed down so its bottom edge is lower than the top of the upstand, (although screwing it right down should limit the possibility considerably). A quality vent will not skimp on metal, and will have maybe 2" of upstand above the base. That is usually enough that even a very heavy downpour will not be hitting the roof hard enough for drops to bounce up high enough to get over the top edge. Many of the vents sold are not quality. Link to comment Share on other sites More sharing options...
Neil2 Posted March 24, 2017 Report Share Posted March 24, 2017 11 hours ago, alan_fincher said: This very sensible response seems to have been ignored in almost every post that has followed it. This is the key. If the upstanding sides of the lower part are shallow, (say an inch or less), then very heavy rain will bounce off the roof hard enough that it the gets up under the covering dome, and can fall down inside that upstand. This can happen even of the dome is screwed down so its bottom edge is lower than the top of the upstand, (although screwing it right down should limit the possibility considerably). A quality vent will not skimp on metal, and will have maybe 2" of upstand above the base. That is usually enough that even a very heavy downpour will not be hitting the roof hard enough for drops to bounce up high enough to get over the top edge. Many of the vents sold are not quality. My vents have a shallow upstand, about 30mil and I repeat I have never had a drop of rain/hail/snow through any of them. The kitchen vent is actually set so you can't screw the cap down lower than the top edge of the upstand. The fact that most of the time these vents are full of cobwebs confirms their dry status. What I do notice, and I haven't bothered to compare them with my neighbours boats, is the upstands on my vents are not vertical, they are slightly conical so I wonder if it's this feature that prevents the ingress of heavy rain. Link to comment Share on other sites More sharing options...
Machpoint005 Posted March 24, 2017 Report Share Posted March 24, 2017 It may be worth the OP checking that mushroom bases are properly screwed down to the cabin roof. If they are like mine, the builder had to fix a plane (flat bottomed) brass fitting onto a slightly curved steel roof, so you really need the sealing gunge to work properly. Link to comment Share on other sites More sharing options...
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