Why are we terrified of soft decks?

[Skipper]

There's one stanchion base that is inaccessible on my Bristol. It's behind the quarterberth ceiling planks. When I bought the boat 2 years ago, I noticed some gel cracking around that base. The surveyor said all was good.

I hammered (malletted) all the decks again last week, and found that the immediate area around that base gave me a thud instead of a knock. It appears that the deck hardware had been maintained over the years, except that one, likely due to its inaccessibility.

I removed the top ceiling planks (re-installing while looking original was not easy), removed the bolts, and then pried the stanchion up. It was immediately obvious that the base had been leaking for many years. Maybe centuries. However, it was confined to an area of about an inch in most directions. Soundings gave me a crisp rap further out. Also, there was no indication of leaking belowdecks.

Anyway, I left it rotten, injected some Git-Rot in there, and re-bedded the base. With the stout backing plate, end-grain balsa doing its job to localize the damage, and the fiberglass above and below intact, the stanchion seems fit for duty.

So it made me start thinking about decks. I'm now wondering why we are afraid of soft decks, to the point of them almost always being deal-killers during a sale, and a source of great depression and even panic if it develops on a current boat. My biggest point of curiousity is the question of deck failure. Has anyone a story or pictures of someone's foot going through a deck? What of other structural failures caused by weak decks? Any actual stories? Isn't the hull stiffening accomplished with bulkheads and stringers? What sort of amazing stress would we have to put on a boat with "soft" decks to generate a worrisome failure?

I'm sure there are stories, otherwise we wouldn't be afraid.

 

[centerline]

there have been entire chapters written in books about this... it cant be properly explained here in this small space.
a soft deck is weak... it may hold out the weather for awhile, but it will not hold fittings or weight properly.
when you step on a soft deck, instead of the weight being distributed to the surrounding area and to the hull, it is point loaded at the soft spot and it sags out... as it sags, the deck is pushed down and pulled slightly inward towards the rotted spot from all directions. this causes stress all around....
a few times of this happening is usually ok, but with it flexing many times or too much weight and it will cause fractures and failures elsewhere in time....

your situation with a loose and rotted stanchion mounting, the stanchion can easily be pulled out with very little effort.. so could a cleat. when it fails the mounting hardware may hang in the top layer of fiberglass and pull a strip loose from the deck, rather than just a small area under the fitting.....

a small area of rot may not be an issue for awhile, but it WILL get bigger and worse... and the bigger it is, the more intense and expensive the repair will be when you fix it....

and if you dont fix it, the resale value plumments, cuz no one wants a rotted boat...

there are many more reasons, but i dont have that much time....

 

[Ross]

They only are a problem during a major storm at night 300 miles off shore. On sunny days with light winds and blue skies with pretty white clouds they are nothing to worry about.

 

[Maine Sail]

This deck was soaked.....

 

[Indysailor]

They only are a problem during a major storm at night 300 miles off shore. On sunny days with light winds and blue skies with pretty white clouds they are nothing to worry about.

+1 There are many boats where I sail that are in what many would consider a state of disrepair, incapable for extended or heavy weather sailing. I've stepped on friends' boats and have been alarmed at the squishing sensation of their decks, or stepped below to feel the oppressive humidity and the pungent odor of a wet boat. However, it's an inland lake, basically a day sailing destination, with no waves to speak of, safe harbor never further than a few minute motor away and winds rarely above 15 knots. Many sailors here have no aspirations beyond what their incomes and their scarce free time provide and there are very few places that know what to do with a sailboat, especially one that is thirty or more years old (you're in luck if you have a pontoon boat, though). These owners would rather spend free time sailing and not grinding, sanding or breathing noxious fumes, so they accept the structural imperfections and cross their fingers. If they do have some failure like a stanchion that comes out of the deck, they will cobble together some repair, usually not to the standards discussed here, but most of these boats exist without problems or catastrophic failure for many years. It's not my preference, but then I don't see myself as the last owner of my boat; the next owner of theirs is likely the landfill.

 

[Ross]

Everything on a boat should be strong enough that when you are in a storm you are not going to be concerned about that weak place that you have been meaning to tend to.

 

[Scott T-Bird]

I have soft decks underneath the windows, which leaked for years, probably, before we bought her. I noticed the decks before purchasing and the surveyor didn't even say anything about it. If I had read comments from this forum before purchase, I probably wouldn't own her today ... c'est la vie!

The surface flexes when I walk on it but I haven't noticed any difference in almost 10 years or any stress cracks in the gelcoat. I think I will fix the decks after I replace the windows. I cured leaking windows with a lot of silicone, which looks like hell but won't matter once they are replaced. I'm hoping to make window replacement a project for this winter.

I've sounded around stanchions and the chainplates and don't find any concerns there, and the chainplates are secured to bulkheads anyway. It does bother me some that the soft decks are fairly close to the area where the chainplates penetrate.

I haven't decided exactly how I'm going to repair the decks, but I'm leaning towards injecting resin in a series of holes & then painting, rather than removing the topskin. All that feathering looks like too much work for trying to preserve the skin. I'm definitely not going to remove the bottom skin. I don't think I'm up to making it a huge project and I'm not really thinking about re-sale of the boat ... she's going to be with me for awhile, and when she goes, she will probably be a gift anyway.

There is a need to fix several concerns I have about water penetration if I were to move my boat to a location where I could find green water washing across the deck. My bow hatch is fine for keeping rainwater out, but green water will easily leak in. The same goes for my sliding coach roof ... many projects to contemplate and pursue before moving. On a well-protected lake, the concerns aren't so urgent.

 

[Skipper]

These responses are what I thought: That most older boats just go through the rest of their lives with some soft areas. I'm wondering how many otherwise stunning boats have been shunned by prospective buyers due to soft areas or moisture content in the core. If it's only in the side decks, say from a portlight leak, and away from hardware, it seems only a minor defect.

I like Mainesail's picture. Now that's a failure story. Although the base seems lacking a backing plate.

 

[Ross]

When I built my boat I intended to go into harm's way. I knew that I would not sleep well if I left anything less than as strong as I could make it.

 

[Scotty C-M]

"These responses are what I thought: That most older boats just go through the rest of their lives with some soft areas."

Skipper, I read these comments and get a different picture. More of the responses are that these areas are significant and need to be adddressed. Some people just let it go because they sail in very protected areas (lakes). It has been my experience that some small delaminations can be left alone, but watched, as long as they are not near structural components. However, most soft decks are near such areas because those are the areas that get stressed, and leak. You did right by fixing the source of the leak and addressing the rot issue. Hopefully the backing plate extends beyond the affected area, so that the stancion is truly and strongly secured.

 

[Ross]

It doesn't matter until a torn out stanchion leaves a hole in your deck and you are taking green water over the deck.

 

[Skipper]

"These responses are what I thought: That most older boats just go through the rest of their lives with some soft areas."

Skipper, I read these comments and get a different picture. More of the responses are that these areas are significant and need to be adddressed. Some people just let it go because they sail in very protected areas (lakes). It has been my experience that some small delaminations can be left alone, but watched, as long as they are not near structural components. However, most soft decks are near such areas because those are the areas that get stressed, and leak. You did right by fixing the source of the leak and addressing the rot issue. Hopefully the backing plate extends beyond the affected area, so that the stancion is truly and strongly secured.

Yes, need to be addressed. Yet I'm guessing that the majority are never addressed. It's the nature of older boats - they were bought because they were affordable for the buyer, and if that's the affordability range, an $8,000 deck rebuild is probably not in the plans.

People talk about the possibility of holes in decks, flying hardware, etc., but I've only seen one actual rotten-core related story - from Mainsail. Also, the concept of failure seems to involve "storms". I've been sailing a very long time, and have yet to be in a storm. That type of weather is usually reserved for offshore sailors, who may have no alternative but to ride out bad weather. So the concept of good core is a no-brainer for them.

I agree that solid decks are better. It just seems an overreaction by many non-storm sailors if there is core moisture. Case in point is my stanchion issue. If I were selling, and told a prospective buyer that the core is rotten there, he might faint, or ask for a 50% discount. Side-note, possibly irrelevant, during the tens of thousands of miles of sailing, I've yet to need a lifeline to stay on a boat.

I'd like to see actual failure stories. Mainsail's stanchion base ripping out is a good one. Proof of failure is good educational material, sort of like the old "Red Asphalt" movies for driving students.

 

[MrBill_FLL]

soft decks are like rust.

ignored, it only gets worse... but can be useable for quite a long time before failure.

The problem is it will fail at the worst possible time, under stress and high load.

(of course if you don't get into that situation, you can blissfully ignore rust and rotted decks)

 

[MrBill_FLL]

. I've been sailing a very long time, and have yet to be in a storm.

its good to be lucky!

I hope your luck holds.

 

[Merlin Clark]

I don't think anyone is "terrified" of core rot. A good sailor just avoids problems/headache/unnecessary work and cost when possible.
I'd buy a boat with core rot IF the boat was special to me. And then I would fix it.
Living with it would be like living with a leaking roof and assuming it's not going to get worse.
And end grain balsa doesn't stop the spread.

 

[Skipper]

its good to be lucky!

I hope your luck holds.

Lucky? That's like saying a skipper is lucky to have won a race. Or that you're lucky to not have core rot

I find it remarkably easy to avoid storms. "Storms" - that is, Beaufort force 10, or one step above a strong gale.

Anyone with a radio or internet can do it. I've been in windy, rough, miserable conditions more times than I can recount. It's part of the fun. Yet I'll never be caught in the danger of a storm. At least, I can guaranty that until I sail the Caribbean later in life.

 

[Jackdaw]

I'd like to see actual failure stories. Mainsail's stanchion base ripping out is a good one. Proof of failure is good educational material, sort of like the old "Red Asphalt" movies for driving students.

O'day 25. Compromised deck got soft, and wicked water into bulkheads. Chainplate pulled out of the bulkhead, straight up through the deck, and the mast came down. You can see it laying on the seawall , bolts still attached, in the lower picture.

I asked the owner about the soft spot the year before. He said he would 'get around to it'.

 

[Scott T-Bird]

That's not much of a bulkhead fastener. I'd be concerned about it even if the bulkhead hadn't rotted. Maybe I'm not seeing what was left behind, but the shroud fastenings that have been talked about on the smaller O'Days in this forum seem pretty marginal to me. Wasn't there an O'Day 22 talked about that lost the mast when the sheet metal screws pulled out of the deck?

 

[Jackdaw]

That's not much of a bulkhead fastener. I'd be concerned about it even if the bulkhead hadn't rotted. Maybe I'm not seeing what was left behind, but the shroud fastenings that have been talked about on the smaller O'Days in this forum seem pretty marginal to me. Wasn't there an O'Day 22 talked about that lost the mast when the sheet metal screws pulled out of the deck?

Scott,

IIRC, that SS chainplate was about 18 inches long, and 2.5 wide. It was thru-bolted to the bulkhead with 7 or 8 SS bolts. I think it was fine until the deck, and then the interior of the bulkhead got wet. Then it all pull straight up and out. Left a long gash in the bulkhead and a nice round hole in the deck.

 

[Indysailor]

Scott,

IIRC, that SS chainplate was about 18 inches long, and 2.5 wide. It was thru-bolted to the bulkhead with 7 or 8 SS bolts. I think it was fine until the deck, and then the interior of the bulkhead got wet. Then it all pull straight up and out. Left a long gash in the bulkhead and a nice round hole in the deck.

That's an Oday 23, and the usual culprit is not a soft deck, but rather improperly bedded chainplates. I had contemplated bringing this up but the original question was about squishy decks; this is definitely not something that can be ignored as it doesn't take much to rip the chainplates out of rotten bulkheads on any boat.