Stringers - Doug Fir or LVL?

Chris,
There is a thread on a LVL stringer job when the member could not find the Doug Fir in his area. It looked to me that it turned out fantastic. Just watch out for the thickness difference.

cuda,its a difficult choice.for me the deciding factor was upon disassembly,everything was very wet.anything that was made out of ply was mush,doug fir peices were pretty decent considering how wet they were.my concearn was if the lvl were to get wet the rot would take hold quickly.i realize their are several factors to consider here,just my 2 cents

I came across this system on Jamestown Distributors and would be interested if anyone has installed something like it.

If you use CPES and epoxy (recommended), then I would not worry about water on ether the solid Fir or LVL. Just make sure that any holes drilled into the stringer system after layup get CPES'd and then 5200'd. (engine mount lags) If you go no foam and use ply for the sole, then it should be bonded with thickened epoxy and no screws.

I am using LVL in my build and I think it is going to work great. I was wondering about the same thing bbishop1974 so I took a piece of the scrap LVL and put it in my driveway directly under one of my downspouts. It has been sitting there for over a year now and it is still solid. I know it has had time to dry out as well but it has been sitting outside every day the whole time. It is discolored but still as strong as the day I put it out there as far as I can tell.

With the LVL CPESed and covered in multiple layers Epoxy and glass I think it will be just as good and last just as long as Doug Fir.

If you have not found it yet you can see my stringer thread in my signature.

Kris

bbishop1974 wrote: kris[big papa],thanks for your great documentation.its definitly a hard choice and your a pioneer.you have to give us a review when done

Will do!!

What is the weight difference between LVL and fir? seems about double at a construction site.

OverMyHead wrote: What is the weight difference between LVL and fir? seems about double at a construction site.

I have not seen a weight on a new Fir stringer, but my LVL stringer after being cut out and still in bare wood weighed 27 pounds.

Trying to remain open minded here and with all due respects to everyone's good intentions, my only real concern with the laminated beam (laminated veneer lumber)would be where the bolts enter between the veneers. Will the glue prevent a separation of the veneers? In most other respects the LVL may be superior to fir, weight not withstanding. Time shall be the only true test of the bolt holding characteristics.

Eric has posted a real nice,imo,way to solve that problem but I can't find it.Maybe he can repost it.

Jack,
Eric has mentioned a method he has used whenthe stringer strength in in question or when you use a composite. He will drill a horizontal hole in the stringer. Then in the hole insert a piece of round stock steel with a drilled and tapped hole in it. Then from the top run a bolt down into it. Unless very carefully done, this really opens up the stringer to potential water.

In the 40+ years I've been around wood boats, I have never seen a stringer split from a lag bolt.

How's your project going?

Found it and always thought it was a good way to avoid the problems of threading into wood