Wooden I beams

[Jim Fuller]

Has anyone here ever made any structural wooden I beams? I am interested in the brand of glue you used.
Thanks
Jim Fuller

[Jim O'Dell]

If you are talking for a building support, no, I haven't done that. But I built a modified type I-beam for the slide in platform in my van. I used Titebond II because that's what I had. I also used screws through the 2X material and plywood. It's light weight and very strong. I'm now thinking about using this for constructing my 2 10' long benches I'm designing for the multi use wall in the shop.
I would think any glue that will bond the wood species you will used properly would work fine. Let's see what the others say. Jim.

[Ken Deckelman]

The I-joists or TJI's in my house are glued with polyurethane glue, you can see where it foamed in places.

[mark page]

I'm sure some engineering majors will chime in, but I personally do not believe that you can compete with the microlam products that are produced today. At least with the size vs load ratio difference between the two. I don't think I could produce a lam that would hold up to the shear strength of the microlam products. If so, it would take a lot of patience, very precise equipment for the super thin cuts, a hell of a lot of glue, major clamping problems, and then comes the problem of keeping it true and square during production. From my limited engineering knowledge, trying to plane one square and true after production would compromise the layers strength that were cut or shaved through during the procedure.

What I have done in the past is use microlam I beams for structural support on load bearing headers, etc and then encased the total I beam with solid 4/4 wood (three sides) to appear as a solid beam with 2x forming the the nailer width on each side. This works well aesthetically for me in the past several projects that I have done, open wide doorways, basement ceiling finishing. I believe the hardest project done was on a vaulted finished ceiling, and the client wanted a solid beam look spaced on 4 ft intervals. I had to tie four sided 4/4 board beams into the trusses and angled into the walls. Major sheet rock work required afterwards(and not by me!!!). Was also impossible to have scaffolding involved on the total project due to stairwells etc. A lot of ladder work and felt a might bit dangerous too. I will never undertake this project again with the same architectural situations. But the client had more money than sense IMOHO and I had more sense than money at that time but did the job anyways.

[Cliff Rohrabacher]

I'm sure some engineering majors will chime in, but I personally do not believe that you can compete with the microlam products that are produced today. At least with the size vs load ratio difference between the two.

You can out-do the engineered truss makers very easily. The key for the DYIer is to "over-do" it.

Those beams are engineered to be very close to their load specifications and to be as cheaply produced as possible. That takes some engineering to accomplish.
A major part of the work is done to get a lot of performance out of as little material as possible. Because of that one fact I dislike them a great deal and will not use 'em.

The home builder can make them (& make 'em better) by simply going overboard. I'd say to use 3/4" marine grade ply and large top and bottom strips and away you go. You'll have a far stronger beam that will be more versatile - and it'll weigh more too. I'd use any high end water/moisture resistant glue such as tightbond III. The industrial PVAs are better but you can't get 'em in quantities smaller than 5-gallons and they have a very short shelf life.

My preference when laminating for strength is to forgo the whole slick geometry of the engineered truss and simply slap a few 2*12" boards together using each to support the other. Then glue and screw 'em together. It's heavy and bulky but it won't ever fail.

[Clayton Masterson]

If you are looking for a large span member, you may want to consider a "flinch beam" I think that's the correct term. It is a length of plate steel sandwiched by 2x's to create a beam for long span, large load applications.
Find a good architect in your area to check on local codes and options.

[Keith Cope]

Jim,

I think Clayton might be on the right track--a flitch beam is fairly simple and quite strong. I did a quick search and found this NAHB manual online:

http://www.toolbase.org/Design-Const...tch-plate-beam

Keith

[Cliff Rohrabacher]

The steel and wood laminations are used extensively in rural NJ and PA in old buildings and they manage to remain in keeping with the older style of architecture.

However for strength, nothing beats a steel H or I beam. I put a 19 KIPS I beam running down the center of the 40' length of my shop when I built it. On top is a flat roof and a big recreational deck It'll take any snow load (even wet rained on snow) and I can fill the deck with people and nothing moves - ever.

[Greg Cuetara]

Being a Professional Engineer please be very careful using tables which you do not understand or understand all aspects of. Read all of the notes before and after and even then you will most likely miss a very important piece of information with regard to support at the ends or lateral support along the length of the beam. Cliff is somewhat right that the material they use is not the best and that they push the limits on the capacity of the members.
Jim please try to describe what you are trying to do because there may be a better way than to recreate a wood I-beam. Another option would be to recreate a wooden truss with 2x4 or 2x6 material which you would probably be able to do easier than a wooden I-beam. I would definately try to find a good exterior grade glue like Cliff said "any high end water/moisture resistant glue such as tightbond III. The industrial PVAs are better".

[Jim Fuller]

What I am building is floor trusses for a work shop. they will be 24 feet long. I can buy preengineered beams, and I have reasearched this a lot, 11 and 7/8 inch beam will carry any load. On top of that I will have a support wall in the center to seperate my shop.
The preengineered beam manufactures use polyurethane glue. It is "Purbond" brand name. It meets ASTM D 2559 specs. I can't find another glue that meets that spec. I think it is because it is a poly and is waterproof. Heck I plan to have it inside, so I don't see why Titebond III wont work. I have done some laminations before and know the difference in the glue as far as the stiffness is concerned after it sets.

The beam will be 2X4's ripped and dadoed to accept 7/16 OSB. This is what you get when you buy a manufactured one. Only I don't have the Purbond glue.

Whee, I hope this explains my case. Again Thanks

[Cliff Rohrabacher]

You could use epoxy instead of purebond.

[Robert Trotter]

Hi Jim, I don't know how you will layout your floor and how many supports you will have along its length or if you are trying for a single span or what the actual loads are (static or dynamice) etc etc....

BUT..I would think that strength or load bearing will not be the main factor in your decision. It will be deflection. Many beams will be plenty strong enough to take the loads intended in design but they could deflect quite a bit for that load. Usually in the average building design deflection will be the design criteria that will decide which size beam or spacing etc to use. For a workshop I am sure you don't want to be playing the wobble board every step your take (sounds like a song ). Check your calculatinos or the design tables by the manufacturer for the deflection data. Anyway that is my suggestion for your. Take it for what it is worth. (free advice)

Robert

[Ken Deckelman]

You could also use PL Premium Poly Glue.

[dan moran]

do yourself a favor and buy some LVL's (2 @ 11-7/8" x 1-7/8" x the length of your shop to go under/over/between?? the wall you're building..

it also might be a good idea to intersperse a few of em in your floor layout- maybe substitute every 4th I-Joist or so with an LVL..

i dunno, ive stood and bounced(i think it was my rythm cause i only weighed 145lbs at the time) on 12" TJI framed floor decks with a clear span of 20'.


good luck

[Justin James]

Jim, from what I've read, Titebond III has some creep (I know most other PVAs do). This may make it unsuitable in this application.