Using oak for boat decking

Discussion in 'Materials' started by rob2112, Mar 30, 2024.

  1. rob2112
    Joined: Mar 2024
    Posts: 2
    Likes: 0, Points: 1
    Location: Oxford

    rob2112 New Member

    I’m helping a friend with a project boat and they have had oak beams delivered for a new deck. It’s a 50ft trawler converted to a live-aboard but in need of “updating”.

    What thickness would the planks need to be for the decking? Yep the beams need planking first.

    Thanks in advance, appreciate any help/guidance you all may have
     
  2. Will Gilmore
    Joined: Aug 2017
    Posts: 944
    Likes: 437, Points: 63
    Location: Littleton, nh

    Will Gilmore Senior Member

  3. jehardiman
    Joined: Aug 2004
    Posts: 3,773
    Likes: 1,167, Points: 113, Legacy Rep: 2040
    Location: Port Orchard, Washington, USA

    jehardiman Senior Member

    Welcome to the forums Rob.
    As Will implies, there can be some issue with red oak, an open grained wood, as a decking. Prone to splinters and checking, you will have to give it some sort of thick coating to prevent weathering and water intrusion. "English" or "European" oak (Quercus robur) is classed as a white oak and has less water and rot issues, will work well for deck beams, but is not really a preferred choice for deck planking. Unless you have pockets deep enough for teak, generally, on this side of the pond, softwoods (fir, cedar, and pine) are used for deck planking because of their better workability and weathering. Lots of trawlers out on the west coast have fir or cedar decks and as long as you keep them oiled or painted, are effectively life of vessel.
     
    Will Gilmore likes this.
  4. Rumars
    Joined: Mar 2013
    Posts: 1,801
    Likes: 1,123, Points: 113, Legacy Rep: 39
    Location: Germany

    Rumars Senior Member

    Plank thickness depends on the deck construction. A traditional laid deck with caulked seams has different needs then something with a plywood substrate. Even a deck with a substrate has different thickness planking depending if it's screwed or glued.
    On a traditional deck I would expect planking between 1 1/2 and 2 1/2. Decks screwed to a substrate need a minimum of 1/2 because of the plugs, while glued decks usually top out at a maximum of 3/8.

    Oak decks are encountered only on working vessels in nordic waters and are a nightmare you don't want. If local english woods are preferred, first choice is larch, second is scots pine or douglas fir. Otherwise there are a bunch of tropical woods, right up to teak.
    You can always go to the low maintenance option, fiberglassed plywood followed by paint.
     
  5. fallguy
    Joined: Dec 2016
    Posts: 7,641
    Likes: 1,688, Points: 123, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    You do NOT use red oak.

    The planking dimension is already established. If you change it; you'll encounter problems.
     
    Howlandwoodworks likes this.
  6. bajansailor
    Joined: Oct 2007
    Posts: 3,614
    Likes: 1,574, Points: 113, Legacy Rep: 37
    Location: Barbados

    bajansailor Marine Surveyor

    This sounds like an interesting project - can you tell us some more about it please?
    And if you can post some photos of the vessel as well, then even better.

    I have a feeling that the Forum members here will be able to help you and your friend with many other aspects of the rebuilding of this project trawler, as well as the useful advice offered above re the timber decking.
     
  7. philSweet
    Joined: May 2008
    Posts: 2,694
    Likes: 458, Points: 83, Legacy Rep: 1082
    Location: Beaufort, SC and H'ville, NC

    philSweet Senior Member

    Oak is good for beams but a poor choice for deck planks. It moves too much for deck exposure and will blow out pretty much any fastening system. When it wants to warp due to differential temps or moisture on the top/bottom surfaces, It's going to warp, and it will take the rest of the boat with it. That's not how you want decks to work. Find a more dimensionally stable material whose movement can be constrained with proper fastening, bedding, and calking. Either that or you pay someone to swab the deck 24/365.
     
    bajansailor and fallguy like this.
  8. skaraborgcraft
    Joined: Dec 2020
    Posts: 378
    Likes: 113, Points: 43
    Location: sweden

    skaraborgcraft Senior Member

    What Rumars said. Having lived with traditional decks, I would go for plywood and epoxy-glass sheathed. Most of these boats rot from the deck down, usually around the bulwark stanchions. If you go traditional, there is options for larch in long lengths, though imported Opepe can often be had at better pricing.
     
  9. rob2112
    Joined: Mar 2024
    Posts: 2
    Likes: 0, Points: 1
    Location: Oxford

    rob2112 New Member

    My friend has already brought many many oak beams to plank and use as decking - not always the best at researching projects before jumping in. Is there a way to use the oak over a plywood “base” more for the aesthetic look than as a functional deck?
     
  10. skaraborgcraft
    Joined: Dec 2020
    Posts: 378
    Likes: 113, Points: 43
    Location: sweden

    skaraborgcraft Senior Member

    Yes, he could rip it into 50mm x 15mm strips and screw into a plywood sub deck, but everyone of those screw holes is a potential pitfall down the road, unless first bored oversize then filled with epoxy. Oak can be problematic with epoxy due to acids within the wood, so the whole lot would need to be bedded down on some kind of Sika/tar/bitumen.
     
    Will Gilmore likes this.
  11. Will Gilmore
    Joined: Aug 2017
    Posts: 944
    Likes: 437, Points: 63
    Location: Littleton, nh

    Will Gilmore Senior Member

    https://www.google.com/url?sa=t&sou...AQFnoECA4QBg&usg=AOvVaw15DSTYWQBTLY2R-bArYFvp
    This article compares polyester resin vs epoxy resin. It recommends epoxy over polyester when working with oak, among other woods.

    Lay a plywood glassed deck and adhere the oak strips over it. I don't see any reason to use fasteners if you get a good adhesion surface. Be sure to clean the oak with acetone, to remove surface oils and acids. Perhapse the natural acid in the oak would loosen the bond over time, but they should be easily reglued, or replaced as necessary.
     
    BlueBell likes this.
  12. Rumars
    Joined: Mar 2013
    Posts: 1,801
    Likes: 1,123, Points: 113, Legacy Rep: 39
    Location: Germany

    Rumars Senior Member

    Of course there is. Build the deck from plywood, glass it over, glue down 9mm thick oak planks. Search for "glued teak deck" to see examples.
    Sell the unused oak beams, or use them for something else.
     
    Will Gilmore likes this.
  13. philSweet
    Joined: May 2008
    Posts: 2,694
    Likes: 458, Points: 83, Legacy Rep: 1082
    Location: Beaufort, SC and H'ville, NC

    philSweet Senior Member

    Are the beams old? That may help a little here. You need to find out what species and where harvested, and if possible, how old. After resawing (dimensions will depend on species), you can try to treat the oak to make it more compatible with structural epoxies. This is easier with old wood. You will need to tell the epoxy formulator you are working with oak. If you are staying up north, this has a decent chance, but I wouldn't even attempt it in the tropics.
     

  14. jmwoodring
    Joined: Apr 2012
    Posts: 31
    Likes: 3, Points: 8, Legacy Rep: 10
    Location: Texas

    jmwoodring Junior Member

    Will Gilmore likes this.
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.