Trailer Boards

[lxskllr]

Oak tree's(red/white?) down, and some time over the next month or so I'll make some trailer boards for the boss. Dimensions are 19'-8"x6'-4"x1-1/2". They'll be single span, and I'm thinking 6 boards across. Heaviest load will be a rubber tracked Bobcat skid loader, don't know the exact model.

Question - the 1.5" thickness gives a flush fit with the trailer frame, and is what's on there now. Boss mentioned maybe maybe making them thicker so they'll be above the frame. Will making them thicker gain anything with durability or capacity, or will it just make things needlessly heavier? He was talking 2" thick, which I think is too much, but maybe 1-3/4" thick? Opinions?


edit:
Bonus questions... What's a deck like that worth? I'll bill it as misc office on my time sheet. Also, what's the lifespan of an oak trailer deck that isn't particularly well cared for? I figured I'd make a spare set of boards for it. I'd guess he has ~20 more years of hard work left in him. Will two sets of boards last that long?

[Ljohnsaw]

The wider the board, the more it will cup.  I wouldn't go wider than 10" (~8 boards) or even stay down at 8½" (9 boards).  You don't mention what the spacing of the cross supports are.  That makes a big difference but I'd lean towards 2" if the spacing is far (4'?) and 1¾" if close (<3') - but I tend to overbuild.  If white oak, that should last a long time.

[Magicman]

They'll be single span

Are you saying that there is no underneath support between the front and the back?  

Personally I prefer to stay with the manufacturer's 1½" thickness to eliminate the need to dado rabbet the ends to fit under the trailer decking attachments.  I have done it both ways and one advantage of the thicker decking is to prevent ripping the top support from the back edge.

I don't think that strength should matter either way.  

White Oak is much more rot resistant, but sometimes wear & tear takes it's toll before rot is an issue.

[lxskllr]

There's mount points at some spacing underneath, but I have to get under it to measure them. The existing boards were single sticks, and I figured I'd do the same thing since I can. Nice thing about milling yourself is you aren't constrained to standard dimensions  :^)

[Magicman]

Turn the smile (pith side) up so that the natural cupping will turn the board edges downward.

[moodnacreek]

The best size is 2x8 or 1 1/2 x 8. 2x6 is not so strong and 2x6 will not saw as nice a plank as 2x8 in hardwood. I have been doing trailer planks for a long time. In my area locust and white oak are what it needs to be.

[lxskllr]

The species was what I had. Poplar would be better than what's on there now  :^D  Locust is an interesting suggestion. I just bucked up a bunch to 8' lengths in his woods. He said he wanted some for fence posts, and now it looks like they're just gonna sit back there. I'm a little irritated tbh. For a year he's been saying he wants my giants next to my driveway. I get him some of his own, and he loses interest  :^/

[Bandmill Bandit]

Question - the 1.5" thickness gives a flush fit with the trailer frame, and is what's on there now. Boss mentioned maybe maybe making them thicker so they'll be above the frame. Will making them thicker gain anything with durability or capacity, or will it just make things needlessly heavier? He was talking 2" thick, which I think is too much, but maybe 1-3/4" thick? Opinions?

I have done quit a few new build and re-decks over the years. Materials from red or white oak to plain old spruce, store bought lumber and custom milled by me since I bought my mill.

I cut custom size to fit deck both for plank width and thickness.
I measure width and then trim to a size that will make ALL planks the same, with the goal to be 7"< and >9" for width most of the time.

For thickness I do the depth of the deck side rails to the deck support cross members + minimum 1/8 to 3/16 depending on the moisture content of the wood being used. I also use a rounding router bit on all the plank edges and ends to reduce splintering as much as possible.

The thickest/widest I've cut so far was 2 7/8" x 9 9/16" for a lowboy oilfield hauler from Hemlock that had cross members every 12 inches.  

Below is a pic of the latest one I did and the smallest as well. I built the trailer 2001 and used dressed construction grade spruce 2"x"8 studs at the time so ended up with 1 x 2"x6" to get a good fit.

This time they are Aspen 1 9/16" x 7 5/16" which gave me an 1/8" space between planks since the lumber was dry to about 8% poke tested. I did a liberal 2 coat water repellent BEFORE install.

Next time (IF I am around to do it) I will weld tabs to the cross members and put stainless 1.25" screws in from the bottom to eliminate the holes in the deck surface.




It turned out very well and is one tough deck.    

[firefighter ontheside]

I'd imagine the original deck boards were treated yellow pine.  If you replace with the same size in clear white oak you will go up in strength, but not have to adapt the trailer for the change in dimension of boards.  I think my trailer has crossmembers every 24".  It is called a heavy car hauler.  The same trailer with 18" spacing was called an equipment trailer.

[Skip]

Poplar would be worth next to nothing , just saying . Red elm If you can get it would be the bomb .

[Southside]

Depending on the use I have used quarter sawn gum for trailer decking, skidder / dozer trailers that tear the deck up. Saves $ and is tough as nails. White Oak would be more rot resistant, but the grousers tear it up sooner than that so why spend the $. 

[moodnacreek]

If  it's a 'bulldozer' trailer that destroys the planks before they rot you want hickory.

[stavebuyer]

If  it's a 'bulldozer' trailer that destroys the planks before they rot you want hickory.

A buddy of mine sawed out a black gum truck bed on an old 2 ton truck he used for hay and cattle. It didn't split but only lasted a year before it rotted.

[brianJ]

If  it's a 'bulldozer' trailer that destroys the planks before they rot you want hickory.

A buddy of mine sawed out a black gum truck bed on an old 2 ton truck he used for hay and cattle. It didn't split but only lasted a year before it rotted.

Of course!!   There is nothing to hold in moisture against that gum wood like loose hay and cow poop.   Not only that but enclosed like that keeps it shaded.   This has nothing to do with anything the rest were talking about.

EDIT   Re reading this thread I see I misjudged Stavebuyers tone.   Be alert some wood is worthless within the year if it stays damp

[Old Greenhorn]

Of course!!   There is nothing to hold in moisture against that gum wood like loose hay and cow poop.   Not only that but enclosed like that keeps it shaded.   This has nothing to do with anything the rest were talking about.

Your comment seems a little harsh. Stavebuyer was just adding his experience which is now part of the conversation. I think his comments fits just fine.

[Southside]

If  it's a 'bulldozer' trailer that destroys the planks before they rot you want hickory.

Around here Hickory will bring a much better price than gum, thus why I have gone that route.  

[scsmith42]

We typically saw trailer decking at either 1-5/8" for standard trailers or 2-1/8" for low boys.  I've done some 2-1/2" decks too.

If left untreated, white oak will outlast red oak.

However, if you choose to treat it with something, red oak will then outlast white oak.  The reason why is that the open pores in red oak allow it to better absorb the treatment, as opposed to white oak.

Black or yellow locust should outlast either of the oaks.

One drawback to oak over treated pine is that it weighs more, so your net payload capacity will drop somewhat.

[stavebuyer]

I apologize to the OP for contributing to the thread drift in regard to my pointing out the downside to gum.

In regard to his original question I would choose white oak over red and edge all of the sapwood. White oak sapwood does not resist weathering like the heartwood. I would saw it 1 3/4 and by the time it shrinks it will be close to the same dimension as original. Oak is stronger at the same dimension as the treated pine and any thicker would be extra weight and work for no gain. 20 years=2 decks. Maybe. Maybe not. The white oak would weather that long with routine care but doubtful it hold up that long if your loading/unloading a D6+ on a daily basis. That's where the mechanical properties of the interlocking species can be helpful. They are light, cheap(few other alternative markets) and almost impossible to split which is oaks downfall. Oak flats often split and splinter before they rot. The inverse is true of gum and hickory. 

[Magicman]

I apologize to the OP for contributing to the thread drift in regard to my pointing out the downside to gum.

I see no drift. What I do see is many different inputs regarding the advantages/disadvantages of using different species.  That shows the value of the Forestry Forum and it's members.

[lxskllr]

Thread drift is great. You can get answers to questions you didn't think to ask(re Magicman and pith orientation), plus it's all just interesting. Organic flow of conversation makes it better  :^)


The type of oak is academic at this point. For better or worse, I'll be using the tree I dropped, and it'll be better than the rotted out deck he has, but y'all think you can ID a dead oak based solely on the bark and/or wood?

[Bandmill Bandit]

You guys in the south have so many more options for wood types for your projects. It makes me very jealous! I can only dream of cutting some of the stuff you guys use for firewood.  

[firefighter ontheside]

A closeup picture of clean cut end grain will be able to differentiate a red oak from a white.  The white will have closed pores.  The red will look like little straws.

[lxskllr]

Via pm, I got a link to this page...

Distinguishing Red and White Oak | The Wood Database


I'm gonna try to check it out tomorrow after work.

[barbender]

Red oak and bur oak (a white oak) are very easy to distinguish up here. Red has a pink/reddish color (surprise!😁) and kind of a sweet and sour smell to it. Bur oak has a tan and brown hue to the wood, the odor escapes me at the moment but it's not as distinctive as red oak.

[lxskllr]

Via pm, I got a link to this page...

Distinguishing Red and White Oak | The Wood Database


I'm gonna try to check it out tomorrow after work.

"Tomorrow after work" ended up being a good bit longer than expected. I looked at it last week, and it's clearly a red oak. I may go up today and get started milling it. The cold weather that never came is leaving fast, and I want to get it done before warm weather gets here.
Any tips on treatment after install? Low cost, and low toxicity are my priorities. Durability would be nice, but with low cost/toxicity, it wouldn't be a problem slopping a new coat of whatever on it once or twice a year. Something like canola oil would be great. Would that work? I use that as my winter bar oil, and it satisfies the two requirements.