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I'm stripping out the interior of my boat to replace rotten floors and joists. The joists are 75mm x75mm what type of wood should I use? Are fence posts adequate? Also on some of the transverse beams it looks like 12mm x 75mm pieces had been screwed to both sides, why would that would be? Would it be better to get 100x75mm posts to replace them?

The boat has had a lot of standing water in the cabin bilge for some time, so a few of the joists have been squidgy enough to pull apart by hand. It's a job that I've been wanting to do for a couple of years but a frozen shoulder has prevented it until now.

 

Thanks in advance.

 

Rob

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I assume you are going to discover the reason for the standing water and cure it before you do anything else - I would work with a hard (oily) wood that can cope with saturation even if it will now be dry............fence posts rely on treatment to keep them going not the wood itself that's why they eventually snap off at ground level

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It depends, really.  Treated timber won't withstand being permanently wet, but an occasional damp atmosphere won't bother them.  I have some Tanalised 2 x 2 up the side of the house in a rack and it regularly gets rained on. It's gone somewhat green, and that gets jetwashed off about once a year.  It's been there about 10 years and is still as solid as the day I bought it. 

 

So as Halsey says, treat the source of the water first.

 

Teak or other oily wood would be great but cost-prohibitive.  You'll be fine with Tanalised timber of whatever size you require, in my opinion - it's what everyone else does.

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49 minutes ago, WotEver said:

Teak or other oily wood would be great but cost-prohibitive.  You'll be fine with Tanalised timber of whatever size you require, in my opinion - it's what everyone else does.

so long as you have found and cured the leak first

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Thanks for the replies.

There were four reasons for the standing water. A long term leak from the hose to the bathroom sink taps, which I fixed when I bought the boat six or seven years ago. The shower tray having a crack, which will be replaced as part of the refit, the pipework to the carolifier, which I'm not convinced is fully cured at the moment but as it'll all need to be disconnected to fit the new floor, will be. Oh and a partial sinking when the base plate had a hole in it, that one has definitely been fixed!

 

I'm attempting to buy the wooden joists today.

 

Rob

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3 minutes ago, p6rob said:

Thanks for the replies.

There were four reasons for the standing water. A long term leak from the hose to the bathroom sink taps, which I fixed when I bought the boat six or seven years ago. The shower tray having a crack, which will be replaced as part of the refit, the pipework to the carolifier, which I'm not convinced is fully cured at the moment but as it'll all need to be disconnected to fit the new floor, will be. Oh and a partial sinking when the base plate had a hole in it, that one has definitely been fixed!

 

I'm attempting to buy the wooden joists today.

 

Rob

Good luck with that. Just come off the phone to my local timber yard. Can't get a delivery before Tuesday and needs to be over £300 at the moment (normally £100). Not complaining, they've only just reopened, running with skeleton staff, the world and his dog want materials and it's Bank Holiday weekend which I'd forgotten about.

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Tanalising is more an anti rot treatment and not a waterproofer.

I've had some success with a waterproofing liquid that I got from Screwfix. I applied it to my garage front some years ago and forgot about it. Recently wanted something to seal my concrete patio (it does wood or stone)  - mostly to keep the lichens at bay.

If anyone's interested I'll go outside and see what it's called...

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Your local fencing or roofing supplies place might be worth a try. Those bits screwed to the bearers? I wonder if they fitted over the steel cross members in the boat?

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3 minutes ago, BilgePump said:

Good luck with that. Just come off the phone to my local timber yard. Can't get a delivery before Tuesday and needs to be over £300 at the moment (normally £100). Not complaining, they've only just reopened, running with skeleton staff, the world and his dog want materials and it's Bank Holiday weekend which I'd forgotten about.

It has been proving quite difficult. The most frustrating thing is my boat is in Lapworth, right by Curtiss' timber yard and pass it everyday going to work. I can see the stuff I want, neatly stacked at the side of the road but they are shut. Realistically, I can just wait a bit longer to order the wood and spend longer cleaning, prepping and painting the metal.

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6 minutes ago, Bee said:

Your local fencing or roofing supplies place might be worth a try. Those bits screwed to the bearers? I wonder if they fitted over the steel cross members in the boat?

It's a job to tell and unfortunately those are the most rotten joists and literally fall apart when you touch them but from what I can make out, the extra bits are the full height of the joist.

 

6 minutes ago, BilgePump said:

Could those bits on either side have been added as doubling once the original bearers started to rot and there was give in the floor?

I don't think so. The amount of work that would have gone into fitting them at that stage wouldn't have made any sense.

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  • 1 month later...

I'm guessing I've missed some excitement! The floor still isn't sorted that's for sure. I've got all the boards and joists but it's been an experience cutting to fit, finding the board wouldn't fit through the door. Taking it back to my mother's to cut, returning again finding it would fit through the door but needed a bit more shaving off, etc. Replacing the floor without removing the side panels is proving to be an endurance feat with at least a few more weeks to complete.

 

Rob

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  • 1 year later...

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