Crack in cabin roof joist under mast base

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paulo122

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A crack has developed and subsequently widened in the cabin roof joist under the mast base. Its a GRP structure but I dont know if there is any 'core' to the joist section. Its sits directly under the mast base. Crack extends right round the joist profile but there is no external sign of cracking.
Not sure if we can simply strengthen the joist with some stainless steel plates bolted right through and sandwiching/spanning the cracked joist area or should I look to have the joist professionally repaired ( cut away and rebuilt I'm guessing ).
Filling seems pointless as i'm sure it will just crack under load.

Grateful for any advice
 
Some small boats have a wooden beam that spans the cabin top and transmits the mast loading to the cabin sides. Water penetrating via badly sealed screw holes etc can cause the beam to rot.

Tell us the type of boat and maybe someone will come forward with some specialist knowledge applicable to your boat.
 
We had similar thing to what you are talking about on our boat after the mast had been put up by the yard, it turned out that the lower aft shrouds were so tight it was forcing the heel of the mast through.
This area had to be repaired professionally and it was tricky.
 
VicS said:
Some small boats have a wooden beam that spans the cabin top and transmits the mast loading to the cabin sides. Water penetrating via badly sealed screw holes etc can cause the beam to rot.

Tell us the type of boat and maybe someone will come forward with some specialist knowledge applicable to your boat.
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In particular, does the boat have a mast compression post (in the cabin, under the mast) or is all the mast loading absorbed by this beam and hence the cabin sides?
 
Depending upon boat type there may be a 'king post' fitted immediately below the mast foot area inside the cabin,sometimes directly to the keel to take the compression loads in the area.
The post may be of metal or timber,ours (Westerly), is a stainless tube and a second post in the cabin to support the cabin roof, made of timber 2" square. I'd guess it is a professional job to be done, de-rigged, and out of the water.
As an aside this distortion may be due to the boat shape altering when ashore and, if a fin keel, weight directed to this central position, slightly distorting the hull,especially if ashore and rigged.

ianat182
 
I bet someone bought a rig tensioning gizmo then proceeded to crank up the shrouds until they sang. Those tensions are fine for a hi tech racer but for most boats common sense should be used.
 
paulo122 said:
The boat is a galion 22.
Click to expand...

That crack would worry me very much indeed. Just how bad it is may depend on what's inside the joist, but it's going to be shades of very badness. One for a surveyor who knows the boat, I think. In the meantime I wouldn't even think about sailing her, and if she's not ashore with the mast down I'd get her ashore with the mast down pronto.
 
No king post in the galion. We suspect the problem started with over tensioning by the previous owner. We hardly payed anything for the boat so if it needs a bit of investment to get it fixed then its not a massive problem. Just wondered if the cosmetically imperfect plating repair would be adequate.
 
I'd be afraid that the crack you see may be just the visible indication that there is something seriously wrong above it. Possibly a wooden beam, as mentioned earlier, that has failed.

The Owners Association is the obvious first place to turn to for advice ( well after this forum of course)
Our Owners Association have produced an Owners manual and replacing the mast support beam is one of the items included in it. We also have a team of Technical Advisers to answer queries and a forum where questions can be asked about the boat.
 
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