Mould under cabin substrate

[captain flint]

I've had a water pump leak. I'm in the process of drying out the substrate - OSB board, sadly. 

 

Although the inspection hatch into the bilge was dry two months ago, it's distinctly damp now, so I drilled a 4cm wide hole in the bow end of the substrate, with a plan to blow air in under the floor at the back of the boat, and a fan drawing air out at the front. 

 

But I had a little sniff through the hole after cutting it, and it smells distinctly mushroomy. I have an endoscope camera attachment for my phone, but haven't yet been able to see - the light on it is too dim, so I'm going to get a little extra light down there and have a look. But I'm pretty sure I'll see plenty of mould. 

 

To add to the annoyance, I've been experiencing physical symptoms that seem to go away when I'm off the boat for any good length of time (1 week +) and come back when I'm on board, and it's just about conceivable that the mould is causing them.

 

Do all boats have mouldy substrates? 

 

Any tips about what to do? I'm certainly not going to rip the floor out. Although I appreciate that's the only surefire method! 

 

I'm thinking just dry it out as well as I can (I also have a dehumidifier and may rig use a bin liner attached to its intake to connect it to the cabin bilge), and see if my symptoms go away, and if they don't, I'll just have to cross that bridge when I get to it. 

 

But any ideas are welcome! 

 

 

[Tonka]

3 minutes ago, captain flint said:

I've had a water pump leak. I'm in the process of drying out the substrate - OSB board, sadly. 

 

Although the inspection hatch into the bilge was dry two months ago, it's distinctly damp now, so I drilled a 4cm wide hole in the bow end of the substrate, with a plan to blow air in under the floor at the back of the boat, and a fan drawing air out at the front. 

 

But I had a little sniff through the hole after cutting it, and it smells distinctly mushroomy. I have an endoscope camera attachment for my phone, but haven't yet been able to see - the light on it is too dim, so I'm going to get a little extra light down there and have a look. But I'm pretty sure I'll see plenty of mould. 

 

To add to the annoyance, I've been experiencing physical symptoms that seem to go away when I'm off the boat for any good length of time (1 week +) and come back when I'm on board, and it's just about conceivable that the mould is causing them.

 

Do all boats have mouldy substrates? 

 

Any tips about what to do? I'm certainly not going to rip the floor out. Although I appreciate that's the only surefire method! 

 

I'm thinking just dry it out as well as I can (I also have a dehumidifier and may rig use a bin liner attached to its intake to connect it to the cabin bilge), and see if my symptoms go away, and if they don't, I'll just have to cross that bridge when I get to it. 

 

But any ideas are welcome! 

 

 

Not enough ventilation. A dehumidifier would help but is not a fix

[Alan de Enfield]

34 minutes ago, captain flint said:

Do all boats have mouldy substrates? 

 

No.

 

Unfrtunately having OSB board as a floor (I presume it is a DIY fit out) you are going to have continuing problems - OSB is like a sponge and sucks up moisture out of the air.

All I can suggest is that you have a fan at one end and an extractor at the other end and have a dehumidifier running 24/7 everytime you are on board.

If you are not onboard and the boat is unheated then it should not be generating much (if) any condensation.

[captain flint]

37 minutes ago, Tonka said:

Not enough ventilation. A dehumidifier would help but is not a fix

It was bone dry until the leak, for the five years I've had it, and looked like it hadn't been damp when I bought it, in which case, dry since 2008. 

 

So whilst lack of ventilation might have increased the build up and might be an issue when it comes to drying it out, but it doesn't seem to have been the cause. 

 

NB I was planning on creating a through draft with fans as said in the op... 

Edited January 26 by captain flint

[magnetman]

Solid fuel stoves are good at drying Boats out. If there is one then keep it alight and turn it up so that the inside becomes too warm for comfort then open the doors. 

 

 

Keep doing that for a while and the drying effect will be noticeable. 

 

Then when you refit the water pump either put it in a sump with a water alarm or higher than the top of the tank with a drip bucket under it. I prefer the second approach because a leak on the tank side, which could go unnoticed for ages, will simply admit air to the pump and a leak from the pressure side will be noticed because the pump will cycle when it isn't supposed to. It is also good to have a switch for the pump somewhere handy and just get into the habit of turning it orf when nobody is there. Like locking the door when you leave. 

 

 

Pumps, in particular the Shurflo variety, will always start to leak at some stage. There is no gasket between the two halves of the pump body. I have recently fixed one by splitting and putting PU sealant in the gap then bolting back together. Don't know how long the fix will last. 

 

 

Edited January 26 by magnetman

[captain flint]

10 minutes ago, Alan de Enfield said:

 

No.

 

Unfrtunately having OSB board as a floor (I presume it is a DIY fit out) you are going to have continuing problems - OSB is like a sponge and sucks up moisture out of the air.

All I can suggest is that you have a fan at one end and an extractor at the other end and have a dehumidifier running 24/7 everytime you are on board.

If you are not onboard and the boat is unheated then it should not be generating much (if) any condensation.

It is not a DIY fitout! 

 

But it's the first fit out that the company did. And I know they look back and think they should have used better materials!

 

Thanks for the tips, Alan. 

 

Don't think I'm likely to be able to make a through draft all the time when on board, though. 

 

I don't think condensation is the main cause, to be honest, as it was always dry in the past. But that's not to say it won't be an issue in the future! 

[David Mack]

If it was dry until the recent leak, it should be dry in future. But if the osb has got sodden it will take a while to dry out - at this time of year the drying will be very slow. With the leak fixed and some additional through ventilation it will probably sort itself out once we get into the warmer months.

[captain flint]

11 minutes ago, magnetman said:

Solid fuel stoves are good at drying Boats out. If there is one then keep it alight and turn it up so that the inside becomes too warm for comfort then open the doors. 

 

 

Keep doing that for a while and the drying effect will be noticeable. 

 

Then when you refit the water pump either put it in a sump with a water alarm or higher than the top of the tank with a drip bucket under it. I prefer the second approach because a leak on the tank side, which could go unnoticed for ages, will simply admit air to the pump and a leak from the pressure side will be noticed because the pump will cycle when it isn't supposed to. It is also good to have a switch for the pump somewhere handy and just get into the habit of turning it orf when nobody is there. Like locking the door when you leave. 

 

 

Pumps, in particular the Shurflo variety, will always start to leak at some stage. There is no gasket between the two halves of the pump body. I have recently fixed one by splitting and putting PU sealant in the gap then bolting back together. Don't know how long the fix will last. 

 

 

Yes, I've heard of this issue arising, and heard that fixes don't tend to last that long! 

 

I will be putting the new pump in a tray with a water alarm. 

 

I always turn the pump off when I leave the boat (there's a switch on the fuse board). 

 

The bloody stove is broken and I'm waiting for a replacement to be installed (it never rains...) . But I have central heating and it gets the boat uncomfortably warm. When the new stove is in place I will be able to get it like a bloody oven! 

Just now, David Mack said:

If it was dry until the recent leak, it should be dry in future. But if the osb has got sodden it will take a while to dry out - at this time of year the drying will be very slow. With the leak fixed and some additional through ventilation it will probably sort itself out once we get into the warmer months.

This sounds right. I can see this is going to be a fairly long process! Bah. Still, grounds for optimism

[magnetman]

3 minutes ago, captain flint said:

When the new stove is in place I will be able to get it like a bloody oven! 

 

That is exactly what you want in a steel Boat which has moisture in it.

 

 

[Sea Dog]

1 hour ago, captain flint said:

To add to the annoyance, I've been experiencing physical symptoms that seem to go away when I'm off the boat for any good length of time (1 week +) and come back when I'm on board, and it's just about conceivable that the mould is causing them.

I don't think this has been sufficiently addressed. Yes is the answer. Lots in the news recently after a child died in social housing after repeated pleas to sort the recurring mould problem. Lots of info on line about the health effects of (any level) of mould in the home. Don't ignore it. 

[magnetman]

I get physical symptoms when I am on a Boat. Fortunately they are positive symptoms as I am on one or other Boat for about 23.7 hours per day on average.

 

 

[captain flint]

2 hours ago, Sea Dog said:

I don't think this has been sufficiently addressed. Yes is the answer. Lots in the news recently after a child died in social housing after repeated pleas to sort the recurring mould problem. Lots of info on line about the health effects of (any level) of mould in the home. Don't ignore it. 

Thanks. 

 

No I'm not ignoring it! And am in consultation with my GP about it. That said, they're not at all convinced the mould is the culprit, and they may well be right. But I'm keeping an open mind as - as you say - it can be a menace. 

[MtB]

Given the (suspected) mould only grew in the wet conditions created by the water pump leak, and you've fixed that now, the mould will probably die and fade away. It needed those wet conditions to thrive and you've changed those conditions (with your fan and no water source) so it will no longer have the conditions it needs. So give it a few weeks or months and the mould will prolly go away. Along with your symptoms.

 

Even if your symptoms are psychosomatic, getting rid of the mould ought to fix them. 

 

 

[matty40s]

We have recently had to deal with a pretty new(2017) boat from a very reputable hull and fitter, which had a water full bilge.

Trad stern, this is important.

 

A very well put together boat on the surface, quality everything. Damp smell and visible water under the forward cabin ballast.

....more water further back....visible damp to woodwork in galley area.

First obvious attention was to the water tank under front deck and water pumps, no leaks.

Then try bathroom, under shower inaccessible, toilet and hand basin, but all hoses seem secure, inch of water in bilge. FlexiCamera under shower sees no leak when shower running and gulper going...

2nd bedroom, over an inch of water, steel ballast over ballast bricks rusting...

We noticed straight away in the front and shower area that the spray foaming of the boat had gone down to the  base plate cross members and the  drainage holes had been blocked, not just one, but every one we could access, therefore any water couldnt drain back.

The kitchen area lower regions were deep in water. 

Around 500 litres were taken out.

Moved the boat into the dock for further investigation. 

Stern Gland impossible to access without dismantling rear cabin woodwork and metal framing, stern gland pouring in. 

Previous owner said " what's the bilge?"

Basically, the inaccessible rear end has led to it flooding the boat forwards. , bit by bit. 

The bilge pump worked, until someone cut the auto wire switch as it was cutting in all the time. The engine bay itself was dry, as the cocooned engine and drip tray was installed above the bilge, so nobody thought the cabin water was coming from the back.....it was slowly going forward under the hidden areas.

The company involved said there was no fault in their fitout.

I suggested that blocking bilge drains in at least 6 visible (the only visible drain holes) areas with sprayfoam was not good practice. No response yet.

 

[MtB]

"Limber holes", I think these bilge drain holes you mention are called. 

 

You write as though the fitting out might have been a different firm from the shell builder. Was this the case?

 

If so this is probably the root of the problem. Who had the sprayfoaming done? The shell builder or the boat fitter?

 

 

 

 

Edited January 27 by MtB
Clarify.

[rusty69]

Our boat was from a supposedly reputable builder too, and doesn't have limber holes,or non that I can see anyway. 

[nealeST]

8 hours ago, matty40s said:

Stern Gland impossible to access

How common is that? And are they prone to letting water pour in? That was a sobering read. I generally assume quality builds in recent times to be the best available….think again?

[captain flint]

11 hours ago, MtB said:

Even if your symptoms are psychosomatic, getting rid of the mould ought to fix them. 

Ha! Funnily enough I have had the exact same thought. Oddly, my GP thinks it's unlikely they're psychosomatic. But also thinks it's unlikely that the mould is the culprit. Go figure. But anyway, this is not a medical forum! 

 

When it comes to the mould, the only thing that bugs me is that if I get the bilge and substrate dried out, the mould will be inactive, in a dormant state, as opposed to actually dying*. That's how it works. If it were to get damp again, it would 'wake up'. And what with it being OSB board that's a slight worry. 

 

Then again, probably one I can live with, especially as I'll have previously proved it possible to dry out the offending area

 

* I think the only way to eradicate it it would be to remove the affected areas completely. Maybe I'll do that if I find a spare £20k(?) to rip out and replace an otherwise very serviceable fit out. I'm joking. 

 

 

20 minutes ago, nealeST said:

How common is that? And are they prone to letting water pour in? That was a sobering read. I generally assume quality builds in recent times to be the best available….think again?

It was a horrible read! 

 

Stern glands can let water in, of course. But you knew that. I'm not sure about pouring in. I guess it could come in quite quickly under the right circumstances, but I imagine it would have been deteriorating to the extent that it should have been noticed for quite time before it got that bad...? I certainly hope so! 

 

My cousin's narrow boat sank after his failed. It had recently been (negligently) repacked. But I don't think it failed suddenly. I think he'd been away, had no automated bilge pump, and I suspect he didn't keep an eye on things. It's a long time ago though, I don't really remember all the details. 

 

I've always assumed that with my  automated bilge pump, and keeping a general eye on my engine hole, that I'd get ample warning of stern gland problems, as opposed to one minute everything's fine and the next your stern gland has failed and the boat's sunk.

 

But that's all basically guesswork on my part, and I'm no expert. I certainly hope it's right! 

Edited January 27 by captain flint

[Bee]

9 hours ago, matty40s said:

We have recently had to deal with a pretty new(2017) boat from a very reputable hull and fitter, which had a water full bilge.

Trad stern, this is important.

 

A very well put together boat on the surface, quality everything. Damp smell and visible water under the forward cabin ballast.

....more water further back....visible damp to woodwork in galley area.

First obvious attention was to the water tank under front deck and water pumps, no leaks.

Then try bathroom, under shower inaccessible, toilet and hand basin, but all hoses seem secure, inch of water in bilge. FlexiCamera under shower sees no leak when shower running and gulper going...

2nd bedroom, over an inch of water, steel ballast over ballast bricks rusting...

We noticed straight away in the front and shower area that the spray foaming of the boat had gone down to the  base plate cross members and the  drainage holes had been blocked, not just one, but every one we could access, therefore any water couldnt drain back.

The kitchen area lower regions were deep in water. 

Around 500 litres were taken out.

Moved the boat into the dock for further investigation. 

Stern Gland impossible to access without dismantling rear cabin woodwork and metal framing, stern gland pouring in. 

Previous owner said " what's the bilge?"

Basically, the inaccessible rear end has led to it flooding the boat forwards. , bit by bit. 

The bilge pump worked, until someone cut the auto wire switch as it was cutting in all the time. The engine bay itself was dry, as the cocooned engine and drip tray was installed above the bilge, so nobody thought the cabin water was coming from the back.....it was slowly going forward under the hidden areas.

The company involved said there was no fault in their fitout.

I suggested that blocking bilge drains in at least 6 visible (the only visible drain holes) areas with sprayfoam was not good practice. No response yet.

 

That is truly awful and is far too common in the world of narrow boat 'design' and building. Far too much emphasis on show and gadgets and seldom enough thought about the fact that it is a boat and not a twee little cottage. A plague on these people.

David Mack a few posts ago is probably right. If it dries out it will very likely be OK. Floors tend to be cool and cool equals dry (ish) but luckily mould and rot seldom flourish unless there is a wet bilge. In my opinion (often wrong) floors are often put down with their edges touching the hull sides. This causes problems with condensation and delamination. There should be a good gap between the steel sides and the floor edge, it won't show because the side panelling will cover it. I worry when I see laminate, lino or vinyl or tiles on a floor as the floor is not a fit and forget item, it should have easy access to the underneath but this is time consuming to build so it almost never gets done. carpet and rugs are far more boat friendly than a beautiful looking house type floor as you will need to get access to the nasty bit underneath sooner or later.

[nealeST]

Yes I’m baffled that a stern gland is made inaccessible…because it is a source of water in. It seems after cutting the wire to the auto device on the pump…the domino effect began. Clearly a reputable boat from 20-30 years ago that had stood the test of time is an excellent proposition. Some of them have hulls like new. Some of them even have solid oak and carpet….

[captain flint]

On 26/01/2024 at 17:30, Alan de Enfield said:

All I can suggest is that you have a fan at one end and an extractor at the other end and have a dehumidifier running 24/7 everytime you are on board.

So, the hole I drilled in the fore section of the substrate was a good fit for a hoover hose. I attached the hose and left the hoover itself out on the front deck. I put my dehumidifier under the steps entering the galley at the aft end, which is right where the inspection hatch is. It made a nice pocket of warm, dry air. Assuming (!) the inspection hatch is the only other major ingress/egress from beneath the substrate, I figured the fan blowing in is a bit redundant. The air is being sucked out so more will have to enter. That said, I can't be sure the inspection hatch is the only ventilation point. I've never seen any others, and I expect it is, but I can't be sure. 

 

Apart from possibly adding in a fan, the thing I'm trying to work out is whether using an electric fan heater placed in the bilge will be better (as I think it would be hotter), or does the fact that there's cold metal which is in contact with the water mesh that condensation will increase in some areas. Will I be better off with cold air? If it wasn't for the cold metal with river water on the other side of it, I'm pretty confident more heat will be good. As it is, I'm scratching my head! 

 

 

[ditchcrawler]

9 minutes ago, captain flint said:

So, the hole I drilled in the fore section of the substrate was a good fit for a hoover hose. I attached the hose and left the hoover itself out on the front deck. I put my dehumidifier under the steps entering the galley at the aft end, which is right where the inspection hatch is. It made a nice pocket of warm, dry air. Assuming (!) the inspection hatch is the only other major ingress/egress from beneath the substrate, I figured the fan blowing in is a bit redundant. The air is being sucked out so more will have to enter. That said, I can't be sure the inspection hatch is the only ventilation point. I've never seen any others, and I expect it is, but I can't be sure. 

 

Apart from possibly adding in a fan, the thing I'm trying to work out is whether using an electric fan heater placed in the bilge will be better (as I think it would be hotter), or does the fact that there's cold metal which is in contact with the water mesh that condensation will increase in some areas. Will I be better off with cold air? If it wasn't for the cold metal with river water on the other side of it, I'm pretty confident more heat will be good. As it is, I'm scratching my head! 

 

 

Dry air is the best.

[captain flint]

16 hours ago, ditchcrawler said:

Dry air is the best

That's why I'm using the dehumidifier but I was wondering about the effects of extra heat

[Alan de Enfield]

10 minutes ago, captain flint said:

That's why I'm using the dehumidifier but I was wondering about the effects of extra heat

 

Warm air holds more moisture.

[David Mack]

22 minutes ago, captain flint said:

That's why I'm using the dehumidifier but I was wondering about the effects of extra heat

My guess I that with a 6ft+ wide baseplate in contact with canal water across the bottom of the bilge space the air you blow in will pretty quickly chill anyway, so it won't make any difference (except to your electricity bill).

Or in other words, any additional moisture which the warmed air picks up as it enters the bilge space, will be matched by a reduction in the amount of water that same air can hold once it has cooled down again, long before it leaves the bilge space at the other end of the cabin.

Edited January 31 by David Mack