Thread: Laminated beams

Dunno a glue name but I've seen the guys from Springwood Beams come out of the hydraulic press room with respirators & full rubber suits covered in glue :eek: :eek: :eek:

I know it a epoxy derivative of some sort.

I hope this helps

For the sort of strength that you would required you would need to use a formaldehyde i think. Not pleasant stuff to work with (supposedly carcinogenic i think!)

Thanks guys, I have used epoxy resin before but for the life of me I can't remember the name of the one I liked. Not arildite but purple'ish in colour and painted it on with a sponge roller

Have a look at the AVSyntec website. Has some good info about the different glues and applications. I have used some of the info when working out what glue to use on different then go to local supplier to get the type needed.

http://www.avsyntec.com.au/Adh/index.htm

Thanks Rowan, that's a good start

Wayne

pva

Thats what I did with a staircase I built. To get it to curve around I laminated together about 20 strips only 3 mm thick, that I agnonizingly ripped from offcuts I'd collected over the years.

Very strong Much stronger than any bearing or joist. Lots of glue surface area though. Guess you don't want to laminate so thin a strips.

But then , epoxys expensive , isn't it ?

No, I wont be using thin strips but you make me wonder about PVA. There are so many glues about now, int. and ext. aquadhere etc. The beams would be exposed in the roof and sealed so I wonder if PVA would work. I've plenty of time to research.

Wayne,
PVA tends to creep with time and pressure, making it unsuitable for structural applications. I would assume that your beams would need to be designed by an engineer and that they'll specify glue type and application details.

Mick

Wayne,
PVA tends to creep with time and pressure, making it unsuitable for structural applications. I would assume that your beams would need to be designed by an engineer and that they'll specify glue type and application details.

:eek: Geeez Mick, does that mean my staircase is going to come down !! ...... hang on, I probably shouldn't be laughing about that

Originally Posted by attie

I've purchased several tonnes of 45 x 19 hardwood shorts and will be making them in to structural beams for a house and a duplex I'm about to build for myself.

Wayne, out of interest how long are the shorts?

The Encyclopedia of Wood (an American publication) has a chapter on structural beams. The two most important points that it emphasises are that shorts must be end-jointed to one another with scarf or finger joints to provide structural strength, and that the glue should be phenol-resorcinol which should cure under clamping pressure.

I wonder whether you would have the facilities to make the finger joints and clamp the beams.

Rocker

Ian
The shorts are 1800 and 2100, looks like I'm in for some fun.

Rocker
I don't have a finger jointing machine but they would be cured under pressure. The main beams will be curved to the roof line with a wrap over roof. Sounds like I'm in for more fun.

Better re-think this project

Wayne

I think you have to use resorcinol, but there are Australian Standards on laminated beams that you should study first.

Wayne
I am looking to do something similar myself for a project we are building on the NSW north coast.
I was asking the rep from Weldbond about it & after some discussion, the Weldbond Professional (yellow) glue was what we reckoned would do the job.
I have been using this for other projects for quite a while and am please with it's results.
Dunno what timber I will be using for my beams yet - won't be making them till late next year I reckon.
My design calls for a complex curve so will probably have to have an engineer do the specs to keep council happy.
Should get the approved DA back from council shortly - can't wait to see the surprises they have in store for me!!!