sunken roof

Micky

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A friend of mine has a 30ft yacht and the cabin roof has began to sink in slightly, just enough to prevent closing the loo door.
He would like to know if this is going to be a problem likely to worsen or should he just cut half an inch off the loo door.
If he needs to add any reinforcement, what would be the correct methods to rectify it please.
 

machurley22

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What kind of boat and what's it made of and, most importantly, is the mast deck- or keel-stepped? The learned forumites will need to know, to be able to advise.

Dave
 

machurley22

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[ QUOTE ]
I'd suspect there's not much of a compression post under the mast.

[/ QUOTE ]
If that's the case then that's almost certainly what's needed. Any sagging caused by compression from the mast is only going to get worse. I installed a post on Silkie and it's a relatively painless process. There's an article here on the HOA website.

Dave
 

bluebosunsmate

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Yes it will get worse over time.

Make sure the mast stays are not over tight and over loading the mast base.

A solution I have used for similar-and it was a dockyard job...

The following make the assumption that you have access all round the bulkhead door.

You will need some hefty timber though I suppose thick ply doubled or even trebled up would suffice.
One piece is to be shaped to fit the correct shape of the deckhead/roof and needs to be slightly wider than the width of the bulkhead door and the two supprting timbers.
Two pieces to be uprights supporting the arch. from arch to inside the hull.

Make an arch which is shaped to fit the deckhead fixed to one side of the bulkhead and supported by timbers running each side of the door the other side of the bulkhead attaced to plates epoxyed to the inside of the hull.

Ease all the stays supporting the mast or unstep the mast.

Using adjustable props (can't remember what the proper name is - like builders use to support the ceiling when taking out a wall) gently lift the deckhead back to the correct position. use softwood wedges unde the tabenacle if necessary.

Pack out any gaps using a two part filler/ply strips or whatever will do the best job.

Jack up the centre of the bulkhead if possible/necessary.

Drill through arch piece and supports and bolt and glue together. Drill through supports and bolt and glue to bulkhead.

After glue and fillers have fully cured you can restep the mast.

Other options include:
A simpler solution may be to jack as before but use ply sheet cut to fit the deckhead shape and around the top of the door frame basically as big as possible to spread the load across the bulkhead and bolt through and glue.

A large plate under the mast to spread the load.

And so on
 

fireball

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The props are acroprops .. can be hired from your local scaffolder - I got one to shuv up the stern when she's ashore ...
 

oldsaltoz

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G'day Mick,

The only thing I would add to the above, is cut the top off the door and make the bulkhead deeper, this add a bit more strength and perhaps stop it doing the same thing at some later date.

Avagoodweekend.........
 

Gordonmc

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Before going for major surgery it might be worth while checking rigging tension.
On my wooden boat the stays were over-enthusiastically tightened when I bought her... the heads door would always stick (deck-stepped). This is despite a hefty oak arch on the bulkhead.
Slackening off the turnbuckles a few turns solved that problem and also reduced strain on the chainplate frames.
 

steve28

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why have none of you clever forumites asked if the the boat is afloat or ashore ?

If it was ashore i would be thinking along the lines of how its been laid up ?, maybe its not on an even surface ?

I only ask because there are some cupboard doors that jam and are sticky when the boats ashore and they are fine when afloat.



steve

ps my reply can be shot down in flames now
 

boatmike

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I generally agree with the conclusions reached by others but would be very careful using Acrow jacks. Take it easy. If its a home built jobbie its possible (probable) that there is very little compression support under the mast as others have said.
Step 1 should be loosen all rigging and see what effect this has.
Step 2 try gently jacking it out, but spread the load well. If it goes easily OK. If it requires too much jacking up settle for building in some support to stop it going any further. Applying too much force to the deck might cause delamination.
Then re- tighten rigging and trim door if necessary.
 

Lakesailor

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Further to that I did the same, but as it is an 18' open plan cabin boat I could just put a compression strut from the cabin sole to the deckhead. I took cut a hole in the headlining and screwed a block to the bonded-in block supporting the tabernacle.
On the cabin sole I made a large, profiled, hardwood plate to spread the load ( I used garden decking boards ).
It worked well however by doing it as described by Boatmike, that is slacking off the rigging, I didn't gain maximum benefit. Even though I had a captive threaded rod in the top of the strut and a nut to wind up to take up the slack, when I unstepped the mast this year to slip it for some little jobs I found another 2cm of headroom. The weight of the mast, boom and furling gear alone had compressed the cabin roof, even with the rigging loosened right off. If you can, unstep the mast to fit the strut. You'll gain a lot more benefit.
 

Micky

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Thanks for all your replies. I have passed the info onto my mate.

Went down the weekend to take a closer look at the problem. Was surprised to see that there was NO supporting post anywhere near the base of the mast, there is one, but it is about six inches ahead of the base plate. The only thing supporting the weight is the shower door framework.

I guess the first job to do is start to jack up, then decide where to fit some reinforcement.
 
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