teak decks leak

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Keithmilton

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Mar 17, 2014
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Canada
although the black caulk between the planks has been recently redone in our 1977 OA 40 foot trawler there are areas that leak into the cabin.....this is noted especially in areas that are depressed so water sits against the salon wall....so
1. does anyone have any advice to level the deck to drain water better
2. a sealant that could keep the water out
thanks
Keith
 
no easy solution once the planks separate from the decks if that's truly the issue...

if it is..maybe one of the crack and crevice sealers may work..the only way to be sure is pull the teak and redo or trash and glass the deck like many have done.
 

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Problem is the water could be coming from a long way away from where it is ending up. You can try and use water colored with food coloring to find where it is finding it's way in. Then use as mentioned thinned epoxy and more caulking with 5200 to stop the leaks.

But the reality may be that it's time to pull the decks up.
 
Greetings,
Personally I'd stay away from 5200. When it comes time to remove the decks and do a proper job 5200 will just add to the work IMO. Thinned epoxy would work, truck bed liner, putting FRP right over the existing deck will work as well. Many band-aid options available.
 
trk bed liner? does it come in off-white?
 
no easy solution once the planks separate from the decks if that's truly the issue...

if it is..maybe one of the crack and crevice sealers may work..the only way to be sure is pull the teak and redo or trash and glass the deck like many have done.
Only sure way. Otherwise it could be nothing but a bigger mess to clean up. I have been curious about p/u bed liner, and it comes in many colors now. But I would not risk it on top of the teak.
 
Might work on top of teak. Hell I have had so many of my preconceived notions upset here by guys smarter than me, why stop now:lol:
 
Greetings,
Mr. M. "...by guys smarter than me..." Whoa! Hold on there partner. Let's not get too silly now.
gKlUall.gif
 
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My wife and I feel that a teak deck is by far the most superior deck material there is. It's traction properties are outstanding, wet or dry. And it looks good if it's in good shape and is properly cared for. So we have spent a lot of time learning how to care for the deck on our boat.

In our opinion, there are only three reasons to get rid of a teak deck.

1. The teak itself is so worn out, weathered, or abused that it's simply not serviceable anymore.

2. The owner does not want to spend the time doing what is necessary to properly maintain a teak deck.

3. The owner simply doesn't like a teak deck. (It gets very hot in hot climates, for example.)

Our 41-year-old boat still has its original teak deck. When we bought the boat in 1998 the deck had been over-sanded by previous owners, or perhaps they had used teak cleaner/restorer which does exactly the same thing as sanding only it does it chemically. EIther way, wood that goes away does not come back. So the boards were getting thin.

But an experienced shipwright determined there was still enough thickness to be serviceable, so we had the main deck re-grooved and re-seamed and I reset hundreds of deck screws and replaced hundreds of plugs. (The teak deck on the flying bridge is always under cover, so it is in like-new condition.)

The reseaming was done with the established seam sealant at the time. It was too bad that it was done before a far superior sealant, TDS seam sealant, came onto the market.

In more recent years I have re-seamed various grooves as the traditional sealant that was used for the re-seam job in 2000 or thereabouts deteriorated or pulled loose from one side of the seam or the other, the most common problem that admits water under the boards. By now TDS was readily available---- my first two tubes were sent to me by TDS when I called them asking about something else--- so all our re-seaming work is done with that material. So far as we're concerned, it's the only sealant worth using on a teak deck, and is what Grand Banks, Fleming, etc. use at their manufacturing plants.

Today, I need to replace a number of seams on the foredeck that have started to deteriorate and a number of the older, thin plugs have come off and need replaceing after I reset the screws. But the processes of seaming, and reseting screws and plugs, while time-consuming, are simple and straightforward once you know how to do them. I find it rather enjoyable to work on the deck. The challenge for us is that our boat lives outside and we have limited time due to my work schedule. So wer really have just weekends.

The deck has to be absolutly dry as a bone before doing any re-seaming work, so the combination of my schedule and the weather up here conspire to prevent us from working on the deck when we'd like to. In a couple of years I'll have more time so we can really tackle the job correctly, assuming we still have this particular boat.

The biggest culprit in a leaking deck tends to be one or more seams that have pulled away from one (or both) sides of the groove. This can be hard to see and requires a close examination of the seams. Once discovered, teh separated section of seam is easily dealth with by remving the old sealant and replacing it with new.

There are a two of techniques for doing correctly; done wrong, the repair will not be very long-lived.

If one elects to replace the seam altogehter, it's very important to use bond-breaking tape in the bottom of the groove, for example, so one needs to learn what it is, where to get it, and how to use it. Some people claim the tape is unnecessary. But everyone I've met or corresponded with who has a lot of experience in dealing with teak decks uses the tape. And when one understands why and what happens if the tape is not there, it become pretty obvious why one should use it.

There is a ton of material on how to repair and maintain teak decks on the Grand Banks owners forum, which makes sense since almost all GBs were built with teak decks and most of them still have them. Searching the archives on that forum will yield all sorts of useful information. I think you have to join the forum to search the archives, but it's free. Grand Banks Owner's Resources

Some of that information has been posted here over the years, but I think the GB forum will yield far more information.

If one decides to remove a teak deck and replace it with fiberglass, they need to know what a big job this really is. It's not a matter of just putting some glass over the teak, although there are people who have done that. It's a bad idea for a bunch of reasons, so I would never recommend that anyone go that route.

I watched a fellow on our dock replace the teak deck on his Island Gypsy a few years ago. He did it a beautiful job--- actually he overdid it in terms of the layers of fiberglass he put down to restore the stiffness lost when the teak is removed from a deck--- and his deck is now strong enough to land a plane on.

It took him a summer and a half of working most days of the week to do the job, and when he was done he told me that had he known how much of a job it really was he never would have started it. But he did a better job than probably the factory would have done had they made the boat without a teak deck.

So one shouldn't view the notion of pulling up the teak and putting down some fiberglass as an easy task. Not if one wants to retain the boat's value, at any rate.

The stop-gap methods often bandied about for "repairing" a teak deck--- fiberglass on top, truck bed liner on top, etc., will work for awhile. But they will fail sooner rather than later because the wood underneath them is not inert and as it moves and swells and shrinks with humitdy and simply being walked on, the quick-fix surface will begin to separate and crack adn moisture will begin to get underneath. Eventually, the owner will face a much larger repair job than he or she had before the quick-fix was applied.

I've seen boats, power and sail, in our marina--- some on our dock--- that have had these quick-fix treatments applied to a failing teak deck. They were okay for a few years. Then the problems started, and in the end, the owners were facing a huge repair task.

So better to do the job correctly to start with. Either fix the teak deck properly, or replace it properly.

Photo is our 41-year old deck today.
 

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my suspicions confirmed.
 
A comprehensive primer in teak maintenance from Marin.
When I had the decks renewed on my IG Europa, the bow was done in painted f/g, 2 layers of glass mat over the existing. The rest which is largely protected was done in fresh teak over one fresh layer of f/g. Saved some $, and it made more sense, I`ve now seen a number of boats done that way.
Keith, it is likely your decks were designed so water ran away from the house, not towards it. Sounds like something has changed.
 
Keith, it is likely your decks were designed so water ran away from the house, not towards it. Sounds like something has changed.

And that might be because the leaks are due to the sub floor under the teak being water logged and rotten. Sadly another reason the deck might need to come up.

The teak decks are not by any means equal it quality between brands of boats. GBs have some of the best out there. Many of the other Chinese/Asian built boats, not so much.
 
The voice of reality

And that might be because the leaks are due to the sub floor under the teak being water logged and rotten. Sadly another reason the deck might need to come up.

The teak decks are not by any means equal it quality between brands of boats. GBs have some of the best out there. Many of the other Chinese/Asian built boats, not so much.

The big problem with teak isn't the teak deck it's the sub straight getting dry rot or the coring under fiberglass failing due to water intrusion through screw holes , penetrations and failed caulking. Teak is oily and caulking has a tough time maintaining bond to the teak thus the need for the bond breaker at the bottom of caulk joints. I can't tell how many failed teak decks I've seen, way too much maintenance for me. Hopefully your leaks aren't a precursor to failed decks. Fien makes a special caulk removing bit for cleaning out your caulk joints it's still a tough job.
 
Despite the age of our deck, we have not found the care and maintenance of the deck to be a huge chore at all. Once the seams are in good shape, it's just a matter of keeping the deck clean, and in that respect it's no different than a fiberglass deck.

One has to clean a teak deck properly, using salt water, Lemon Joy (or some other soap that suds up in cold water) and a mop or doodle bug, and always going across the grain, never with it except in those spots where deck hardware precludes it. But a mopping perhaps once every month or two ,depending on how dirty the environment is, is all that's needed. The rest of the time, the only thing one has to do to it is walk on it.

The image of an owner constantly struggling to maintain a teak deck is a false assumption. Yes, when the seams get old they have to be redone. But our deck was re-seamed in, I think, 2000, and only now are we starting to get some seams letting go of the sides of the grooves. And as I said earlier, this is the old-style sealant, not the vastly improved TDS sealant that has far greater longevity.

We've only had one leak through the subdeck, and that was due to the sealant in a too-shallow section of a groove letting go and coming out. I recut the groove and re-seamed that section and that was the end of the leak.

And remember, our deck is 41 years old now and has taken something of a beating from the California sun during the first 25 years of its life, as well as oversanding and neglect be previous owners. I see decks that are 10, 20 years old that have been properly taken care of with regards to cleaning, and they look brand new and require very little attention from their owners.

So like a lot of things, the "teak decks are trouble" assumption tends to be blown way out of proportion. Yes, they can be crap and are better off being replaced. But this is not nearly as prevelant as it's generally made out to be.
 
You won`t know what is under the decorative teak planking until you look, though the probability is something nasty. My IG had foam substrate decking, still in good order. The underneath decking of two small square areas where the deck steps up to the bow were done in teak. It was black, wet, and soft; and was replaced with foam.
 
teak decks in the North and teaks decks in the tropics are a bit different when it comes to longevity...plus use and how much cleaning they need.

while anything done right/better may last longer, sometimes environmentals trumps even the best install/maintenance.

also whomever posted that not all teak decks were created equal wins a prize too!
 
BruceK - did I understand you, that you painted fiberglass over the bow teak etc.?
 
Not everyone lives in the Northwest

teak decks in the North and teaks decks in the tropics are a bit different when it comes to longevity...plus use and how much cleaning they need.

while anything done right/better may last longer, sometimes environmentals trumps even the best install/maintenance.

also whomever posted that not all teak decks were created equal wins a prize too!

Constant humidity with mild temperatures make a huge difference with wooden decks. Or for that matter wooden boats. Nothing like hot dry summers and wet winters to ruin anything made of wood. If you want to destroy a wood deck in California leave your boat uncovered for a summer.
 
So like a lot of things, the "teak decks are trouble" assumption tends to be blown way out of proportion. Yes, they can be crap and are better off being replaced. But this is not nearly as prevelant as it's generally made out to be.

With respect, and bare in mind I've taken care of as many as 12 GBs at one time in a charter fleet, GB teak decks are not the same as many others. Others use thinner teak from the start. They don't use solid fiberglass sub-decks but ones made of encapsulated plywood. In many cases they were careless when they screwed down the teak decks to the sub-deck and allowed water easy access to the plywood core or even screwed right through the subdeck, etc., etc. And at the cost per board foot for teak these days, many people can not afford to lay down a new deck. Let alone have the time and skills to do it themselves.

Sure it's fairly easy to maintain once you get it in good shape. But getting to that point for some people may not be realistic for many reasons.

And I think based on what I see regularly, poorly maintained teak decks that are either passed a realistic point of no return or close to it, have become pretty common as boats have reached in many cases the age of 30 or more years old.
 
Grand Banks have a subdeck sandwich of a layer of fiberglass on top with a marine ply core and a layer of fiberglass on the bottom. I used to think GBs had solid glass decks despite being told otherwise by the shipwrights on the GB forum. Then I took a core out of our deck to mount a new anchor foot switch. Sure enough, it's a glass-plywood-glass sandwich, just like most other boats of the same type.

What a GB does have is a solid fiberglass hull. No coring of any kind. But the decks and cabin tops are all fiberglass-ply-fiberglass structures.
 
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Hmmm... maybe my memory is failing or they changed lay outs over the years. But I remember other than the woodys I worked on the sub-floor was solid glass.

I'll have to go take a look where the foot switches are install to see if I see what you saw.
 
Our boat is one of the very first glass GBs made. It has a wood core deck. I've seen cores out of 1980s GBs and 1990s GBs from the boats in the local GB dealership that have had hardware like foot switches, windlasses, etc. installed on them.

And I watched a shipwright drill holes through the deck of a brand new 1998 GB52 that was being commissioned next to us when we first brought our boat to Bellingham. The holes were for additional cleats The drill bit brought up wood every time although at that point I didn't realize the significance of what I was seeing. Several years later when we installed additional cleats on our aft deck, same thing.

The person who first told me that GBs have cored decks is Bob Lowe, who for years owned Oak Harbor Boatworks on Whidbey Island. That company specialized (and I guess still does) in the maintenance, repair, restoration, and customization of Grand Banks boats. Bob has worked on every type and model of GB from the woodies to the later glass boats. If there is anyone on the planet in a position to know how GB decks are constructed, it's him.:)

He also founded and continues to participate in the GB owners forum. If anyone has a question about any aspect of GBs, he's the one to ask.

When I said on the GB forum not long after joining that GBs have solid glass decks (this is what I'd been told by a few people) he very tactfully told me I had no idea what I was talking about, and then went on to describe in great detail how the decks and cabin tops of fiberglass GBs are constructed.

Based on the core I took out of our deck, which I still have, the upper fiberglass layer is pretty thick, and the plywood core is quite thick. The fiberglass on the bottom is about half the thickness of the glass layer on top. However, the glass layer on top is not thick enough to keep deck screws from penetrating the plywood core.

So while GB's subdeck construction may be somewhat more robust than makes like CHB and so forth, in reality, and as far as what the effect of moisture getting under the teak planking is concerned, they are basically the same.
 
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I'm guessing there is no such thing as a short answer with you. :lol:

Based on all that, and knowing who Bob is, I'm betting my memory is wrong.

But I'm still going to look. :D
 
Tontoross, afraid not. At considerable expense, the teak and gunk was removed, the zillion screw holes filled, 2 layers of f/glass laid, the surface filled and faired, and then painted in non slip. The rest got the same treatment, except only one layer of f/glass, before laying fresh teak.
 
I just installed a Mahogany teak

I just installed a Mahogany deck that should have been Teak but the boat owner didn't want to pay the price of teak. Oh well he'll pay the price soon enough. I installed this deck over glassed plywood. This is on a custom sailboat so the bottom of the deck is painted. I glued the strips of Mahogany down with epoxy using dive weights and five gallon buckets filled with water to hold it in place. No fasteners penetrating the deck. What a chore. The owner is planing to keep the deck varnished. Current prices for rough teak is upwards of $25 per board ft before machining. Mahogany is is in the $5.30 per bdft range. There is a 38' ketch in the yard right now that will need a new deck, all of the balsa coring has failed and is removed waiting for foam and glass replacement. The owner would like to replace the teak. We will see if she has the money and time.
 

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That's beautiful work Scary!


1983 Present 42 Sundeck
Twin Lehman 135's
✌️
 

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