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Sealing a wooden topped roof?


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Hi All,

I own a wooden topped narrow boat which has been plated with galvanized sheeting before my ownership and i must say they did a very good job the problem is there are many leaks the many many screws from where the sheeting is screwed to the wood there were also leaks from the hand rails which i have successfully sealed but the screws are the main problem :( I have considered removing all the screws and sealing the holes but i don't think this will be a sure seal as the wood they screw into is not it's best the sheeting is also in sections which may also be leaking?? so my question is has anyone had this problem and if so how did you cure the leaks :unsure: Is there a coating that can be applied to the whole roof to seal it all in one go i have even considered coating it with epoxy sealer then laying a lawn of artificial grass to make it look half decent after coating the roof ?? so what do we all think? any help or advice very much appreciated :banghead:    P.S the picture attached is when i first bought the boat in March it has been tidied up since then :D

20170311_161543.jpg

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12 minutes ago, Dave Payne said:

If the screws all run in a straight line? then maybe have a strip of steel sealed down over the line of screws?

Dave thanks for that but there are many in ie the length of the boat and width there are also several sections of sheeting with a sealant type stuff which i think has failed also my ideal easy fix would to be to coat the whole roof and be done :rolleyes:

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Have you removed one of the panels to determine the condition  of the underlying wood?

I would assume if there have been leaks through screw holes that some of the woodwork will be rotten, and by sealing it all over , you may just be temporarily covering up another a bigger potential problem.

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16 minutes ago, rusty69 said:

Have you removed one of the panels to determine the condition  of the underlying wood?

I would assume if there have been leaks through screw holes that some of the woodwork will be rotten, and by sealing it all over , you may just be temporarily covering up another a bigger potential problem.

No i haven't the wood looks very good from inside the boat which is around one inch thick t&g there is little bit of rot where the screws penetrate there are little drips from each one:huh: The sheeting is rust free and i don't really want to disturb it if i can help it i think if i can seal the whole roof asap i think i will have got there just in time before it spreads any further causing major problems in the future :unsure:   

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6 minutes ago, Chas78 said:

No i haven't the wood looks very good from inside the boat which is around one inch thick t&g there is little bit of rot where the screws penetrate there are little drips from each one:huh: The sheeting is rust free and i don't really want to disturb it if i can help it i think if i can seal the whole roof asap i think i will have got there just in time before it spreads any further causing major problems in the future :unsure:   

I am no expert on the subject, but think if it were mine, and I was confident the underlying wood was sound and dry, I would remove each screw individually and inject some thickened epoxy in with a syringe and then reinsert the screws.

It will be interesting to see if you get any responses from people who have actually successfully achieved a long term fix.

  • Greenie 2
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3 minutes ago, rusty69 said:

I am no expert on the subject, but think if it were mine, and I was confident the underlying wood was sound and dry, I would remove each screw individually and inject some thickened epoxy in with a syringe and then reinsert the screws.

It will be interesting to see if you get any responses from people who have actually successfully achieved a long term fix.

Thanks for that rusty ;)

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Just now, WotEver said:

Haven't I read a procedure for painting on canvas with epoxy somewhere?

Yes, or a loose weave glass fibre sheet. A few years ago I saw one of the boast we built in the 70s using vehicle cant rails, rolled top hat aluminium section and plywood sheets for the roof all topped off with said glass sheet and several coats of epoxide paint. Still weatherproof and still looked ok but had probably been painted a few times.

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I fear no matter how you try to repair the roof it will only ever be temporary.

You either do a permanent job and take the cabin off and replace with steel .......

Steel clad over the existing cabin .......

Decide how long versus repair cost you prefer the sound of for a temporary job.

 

If it were me I'd probably go for Steel clad over the existing cabin, unless budget prohibited it.

If so then I'd remove the handrails and using a roll of fibreglass tape I'd apply it over every seam and row of screw heads.

 

  • Greenie 1
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34 minutes ago, zenataomm said:

I fear no matter how you try to repair the roof it will only ever be temporary.

You either do a permanent job and take the cabin off and replace with steel .......

Steel clad over the existing cabin .......

Decide how long versus repair cost you prefer the sound of for a temporary job.

 

If it were me I'd probably go for Steel clad over the existing cabin, unless budget prohibited it.

If so then I'd remove the handrails and using a roll of fibreglass tape I'd apply it over every seam and row of screw heads.

 

That was my thinking but to fibreglass the whole length of the roof with matting the roof it is steel clad with Galv sheeting which is pretty thick as i said it is also rust free i am confident that fibre glassing will seal everything from the elements but my only concern is what the end product will look like ie a roof with many ripples and imperfections/indention's i suppose you can't have it all :rolleyes: 

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1 hour ago, Chas78 said:

That was my thinking but to fibreglass the whole length of the roof with matting the roof it is steel clad with Galv sheeting which is pretty thick as i said it is also rust free i am confident that fibre glassing will seal everything from the elements but my only concern is what the end product will look like ie a roof with many ripples and imperfections/indention's i suppose you can't have it all :rolleyes: 

P1000113.JPG.678e8dfe5a19201adeaf2ed2d0fd6671.JPG

Don't be fooled by the appearance of this roof.  I coated the wooden cabin with fibreglass and epoxy resin.  For five years it looked OK, but it was only a temporary fix and I've now had the whole back cabin rebuilt in steel.

P1210973.JPG.bb1f6199ae1506da444a94f42e06b11b.JPG

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9 hours ago, sharpness said:

How about speaking to the people who do fibreglass roofs as an alternative to felt roofing on garages, extensions etc. No idea what it costs though.

Steve

I'm  about to have my porch roof relaid in GRP.  It has an area of about 10 metres square and will cost circa £1k.

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29 minutes ago, cuthound said:

I'm  about to have my porch roof relaid in GRP.  It has an area of about 10 metres square and will cost circa £1k.

I was going to do it myself ie buy 1mx10m of fibreglass matting/webbing and go for it the cheaper alternative was seam seal the whole roof then lay a artificial lawn on top to hide the imperfections and stop the UV killing the seam sealer ;)

16 hours ago, koukouvagia said:

P1000113.JPG.678e8dfe5a19201adeaf2ed2d0fd6671.JPG

Don't be fooled by the appearance of this roof.  I coated the wooden cabin with fibreglass and epoxy resin.  For five years it looked OK, but it was only a temporary fix and I've now had the whole back cabin rebuilt in steel.

P1210973.JPG.bb1f6199ae1506da444a94f42e06b11b.JPG

That looks good to me ;) where is the bad bit before :huh:

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In the 60s many years ago we used to hire Willow Wren boats from Middlewich and Rugby. These had wooden cabins on steel hulls. Invariably the roof outer layer was made from Vinyl kitchen flooring applied pattern down. Seemed to work very well and withstood any amount of biycles, planks etc thrown on. Comes in long rolls as well.

 

Tim

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5 hours ago, Chas78 said:

 

That looks good to me ;) where is the bad bit before :huh:

The roof timbers had become wet over the years. Although when I added the fibre glass matting and resin the wood appeared dry, in fact deep within the 2" timber roof it wasn't.  As the wood dried out it shrank and became friable; the roof became unstable and the fibre glass began to crack.  

Also the cabin sides were softwood and the slightest movement in the timber allowed cracks to develop.  These needed constant attention and, quite frankly, I got fed up with the Sisyphean task doing the same maintenance year after year.

If you are determined to go down the resin and fibre glass route, read the excellent guide provided by the West System (Google this).  It tells you all you need to know about preserving wooden boats in this way.

The picture below shows the annual maintenance required to keep the boat looking good.

P1120587.JPG

Edited by koukouvagia
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7 minutes ago, koukouvagia said:

If you are determined to go down the resin and fibre glass route, read the excellent guide provided by the West System (Google this).  It tells you all you need to know about preserving wooden boats in this way.

I found the West system guides to be excellent and very informative. I made the mistake of initially buying "The Gougeon Brothers On Boat Construction" (also available in PDF), and though a brilliant book, a bit more than I needed.

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3M 5200 (also Marnineflex) is another goop for bedding screws, being polyurethane based it's moisture cure so won't mind the wood being a little damp.

If the roof is smooth enough, another fix is to lay a strip of aluminium tape (proper stuff, NOT 'duct tape') over the screw heads and burnish it down with a cloth, after a couple of coats of paint it'll be hardly noticeable.

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16 minutes ago, koukouvagia said:

The roof timbers had become wet over the years. Although when I added the fibre glass matting and resin the wood appeared dry, in fact deep within the 2" timber roof it wasn't.  As the wood dried out it shrank and became friable; the roof became unstable and the fibre glass began to crack.  

The timber will be permeable to water vapour whereas the grp is not.  So water vapour from inside the cabin will permeate to the inside of the grp (which is relatively cold) and condense, soaking the wood. There is no way to dry it out and hence rot my well occur.

But if you had put the grp on the inside...

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6 minutes ago, smileypete said:

3M 5200 (also Marnineflex) is another goop for bedding screws, being polyurethane

3M 5200 is good stuff, although it ain't cheap.The Sikaflex offering Sikaflex 292 is also pretty good(dunno if its polyurinated though)

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13 minutes ago, David Mack said:

The timber will be permeable to water vapour whereas the grp is not.  So water vapour from inside the cabin will permeate to the inside of the grp (which is relatively cold) and condense, soaking the wood. There is no way to dry it out and hence rot my well occur.

But if you had put the grp on the inside...

In order to prevent this happening, I fixed a thin layer of ply, disguised as 8" boards to the underside of the roof.  It appeared to work because no condensation from the cabin soaked into the roof timber.  However, when the cracks began to appear on the roof I removed the ply skin and found that although the roof timbers were bone dry, they had become crumbly. 

The lesson is, don't try to bodge and disguise wet timber - it'll get you in the end.

 

P1150094.JPG.91542e7958d67384cfaa972b775c513b.JPGP1120710.JPG.e2830227b25ecaf2a239ac4ba86faf3b.JPG

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Working boats & other wooden cabin boats being repaired or built as the first leisure boats by Charity Dock,  Malcolm Braine, Denis Cooper etc. used T&G boards Pitch paper & 6 mm /1/4" Tempered Masonite soaked in the cut & fitted wet so it tightened up as it dried out a thin strip of timber moulding or alloy covered the joints, with the improvement in sealants the joints now stand a much better/longer in staying waterproof.

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