Outdoor beam glue

[Greg Forrest]

First post here, this site is a great resource but I haven't been able to find the information I'm looking for in the archives.

I'm in the planning stages for a pergola I'm going to build this year. It will be 9x12' to fit my space and my furniture, so naturally I need a 12' beam for the long side. The problem is the the pergola is going on a rooftop patio (I live in an apartment) and I can't get a 12' long piece of wood in my front door! The current plan is to use 2x6 material for the beams, and 2 parallel beams for each run. Since I can't get a 12' board in here I was thinking of face gluing shorter 1x6's together, staggering the joints to build up a 12' 2x6.

First of all, what type of glue should I use? My current thoughts are Titebond III, PL Advance construction adhesive, epoxy, or maybe Gorilla Glue. I'm leaning towards the Titebond, I know that I'll have to get the faces nice and flat for a good bond. I was also planning to screw the boards to apply clamping pressure as well as whatever clamps I have. I know I don't have enough clamps for the whole 12' length.

Second, is this going to be structurally sound? It's a pergola so I won't be walking on top of it.
Also, I will be adding a top cap to the beam so I will end up with an inverted U shape which will add stregth. Of course it will also have to be made up of shorter pieces.

Any input will be greatly appreciated.

[Mel Fulks]

Forgive me for going tangential. Not long ago I was looking for a way to make a structure to hold up shade cloth.Wanted to use PCV pipe if I could find a way to make it attractive and architectural. Decided on a design with CLUSTER LEGS.Google it and see if you like the concept. Basicly it consists of turned pieces going through several squares. For the roof situation it might be especially practical.

[Dave Richards]

I would take a cue from wooden boat building. I would use epoxy for this. I would coat the surfaces and then apply a little slightly thickened epoxy and put the two pieces together with screws. Actually, your faces wouldn't need to be perfectly flat for this. You don't want to squeeze all the epoxy out of the joint anyway.

[Mike Wilkins]

For my outdoor patio, I was able to glue 2 pieces of 2x6 together with nails to hold them while the glue set. I used Titebond III. No problems after 4 years of holding up a roof (figerglass panels).

[Greg Forrest]

Thanks for the input so far.

I should have also mentioned that I will be using western red cedar and the pergola will be getting a polycarbonate roof. It doesn't snow very often here (Vancouver, BC) but there will be some snow load at some point in this structure's life.

[Pat Barry]

I would hoist the 12 footer up to where you need it using a rope and a helper.

[Sam Murdoch]

Epoxy - West system a 5:1 ratio or T** a 1:1 ratio http://www.systemthree.com/store/pc/T-88-c27.ht Good work time, never any issues of not holding. Urethane adhesives are way too foamy by comparison with no otherwise obvious advantage in woodworking (at least to me). Staggering the joints will work very well. A few through bolts might look nicer (could use bronze or stainless - pricey but pretty) and be more easy to assemble, especially if you do a dry run, which I always recommend.

[Greg Forrest]

Thanks for the input guys, I guess this thread has fallen out of sight now. Epoxy seems like it's the way to go, the long open time will be a benefit to me as well.
I plan to get started next month (or whenever it stops raining here). I'll be sure to post up some pictures once it's done, but I work slow so it might take a while.

[Lee Schierer]

How tall is the building? You could rent a versa handler scale_bobcat_versa_handler_v518_model_large__89559.gifto lift all your materials to the rooftop if the building isn't too tall. Or simply hoist the 12' long pieces up one at a time with a couple of people and some ropes.

You may need to check with your local building codes to see if your fabricated beam will meet code.

[Kent A Bathurst]

Thanks for the input guys, I guess this thread has fallen out of sight now. Epoxy seems like it's the way to go, the long open time will be a benefit to me as well.
I plan to get started next month (or whenever it stops raining here). I'll be sure to post up some pictures once it's done, but I work slow so it might take a while.

Epoxy is what I would - did - use. Keep in mind one trick - get some of those hard plastic disposable picnic plates - say 8" - 9" diameter. Mix the epoxy on it, keeping it spread out - this slows the exotherm that cooks it off, since it is not one big lump in a cup.

But first - get a large baking pan of some type. Put it in a plastic trash bag if you value your marriage. Then, fill it with ice cubes.

Mix the epoxy on the plate. Keep it spread out. Set the plate on the ice. Now you got some serious open time.

2-layer laminated WRC garden entrance gate, with epoxy. The joints on on the 2 layers of the circle are all offset, of course - with splines.

Shoulda gotten a photo of it installed, I guess, eh? Here it is with the half-lap lattice work let in to one layer, and also just before the pickets and bottom rail were assembled.


April 10 - 044.jpgApril 10 - 046.jpg

[Greg Forrest]

Epoxy is what I would - did - use. Keep in mind one trick - get some of those hard plastic disposable picnic plates - say 8" - 9" diameter. Mix the epoxy on it, keeping it spread out - this slows the exotherm that cooks it off, since it is not one big lump in a cup.

But first - get a large baking pan of some type. Put it in a plastic trash bag if you value your marriage. Then, fill it with ice cubes.

Mix the epoxy on the plate. Keep it spread out. Set the plate on the ice. Now you got some serious open time.

2-layer laminated WRC garden entrance gate, with epoxy. The joints on on the 2 layers of the circle are all offset, of course - with splines.

Shoulda gotten a photo of it installed, I guess, eh? Here it is with the half-lap lattice work let in to one layer, and also just before the pickets and bottom rail were assembled.

Thanks Kent, that's a beautiful gate!

So I decided to make a test run today, not of the glued up beam, but of whether or not I can get a 12' board up to the deck or not. I had some 1x6's around so I screwed some together to make a board 12'1" long. After a bit of problem solving I was able to get the board in at an angle by pushing up one of the ceiling tiles in the hallway outside my front door. Success!
Granted I will have to carry the boards up the stairs as they will definitely not fit in the elevator, but it's only 5 flights. It will be a lot less work than fabricating 4 beams anyways.

Sorry for the false alarm, I assumed that 12' was impossible as I brought up some 10' boards last year and thought those were a tight fit. Thanks again everyone for the advice; I hadn't really considered epoxy before, but now I will certainly consider it for future projects, especially outdoor ones.

Cheers,
Greg

[Pat Barry]

Are you sure you couldn't bring them up the outside with a rope and a helper? Maybe do it during the day when there's fewer eyes on you.

[Greg Forrest]

Pulling up the boards with a rope really isn't an option. I don't have direct access down to the street below, I would have to crawl out to the edge of an awning that overhangs the building. Also, I'm in the middle of downtown Vancouver; there are always lots of people around. Having a board falling onto someone below or smashing out a lower neighbour's window are not risks I'm willing to take.

The stairwell solution is definitely my best choice.

Now I just need it to stop raining!

[Kent A Bathurst]

........... it's only 5 flights.....

Ah, yes. The Good Old Days. I remember them fondly. There's a lotta gone between me and schlepping wood up 5 flights, I'm afraid.

Good luck.