Glamex LVLs

[OBBob]

Hi There

Has anyone ever used Glamex LVLs? They are manufactured in Melbourne and my timber supplier has priced one for me in place of a Hyspan beam. The problem is that my structural approvals are based on Hyspan ... don't know how comparible they are?

[pawnhead]

From the span tables on their website it looks like they're stronger than Hyspan. How does the price compare? They come pre-cambered as well. I've just installed a 300X63 Hyspan and it's sagged 5mm. And that's before the ceiling has been lined and the bi-fold have been hung off it. A pre-camber would be a good idea.

[OBBob]

The pricing is similar, execpt in my case where I want an unsual size of Hyspan and they will only manufacture it if I buy two, whuich makes the Glamex half the price. Also, (I'm just learining all this stuff ... wish the engineer had have told me) Glamex is F27 and Hyspan is on F16 or F18.

[ausdesign]

'morning OBBob.
there's absolutely nothing wrong with glulam type beams.
I personally haven't nominated them for several years as I have tables & software on steel & also on hyspan, which councils will accept without the need for engineers comp's. - this is going back a while so maybe Glamex now have design software available.

Design wise, in a cathedral situation, the glulam lends itself to being exposed, whereas hyspan probably needs to be covered (by paint, plaster, timber etc) & steel needs to be boxed out & covered.
The visual end result requ. will normally dictate the product used.
From memory Glamex comes in 3 different 'visual' grades .... or maybe that was glulam generally - might be worthwhile checking out if appearance is a criteria.

A couple of closing thoughts - most firms in this field will supply comp's, that you can include with your building application, (for free) if you are using their product.
Secondly if you go with a cambered beam, make sure the 'chippies' or whoever, installs the beam the right way up (you'd be surprised)
Thirdly, is the product termite proof. That beam is supporting a lot of roof area & if destructed could upset the Xmas dinner.

added- i lost track of the post but someone mentioned a beam sagging under load - this will never happen if the beam is designed correctly.

[OBBob]

Thanks Peter

They are doing comps for me now, which should solve this problem. The issue started because I also used the Hyspan software but then AFTER I had my approval I couldn't purchase the beam size needed.

Anyway ... looks good now.

Pawnhead ... has the unfortunate issue above in this thread with a 5mm sag prior to all the load being on the beam. He hasn't really asked for help ... but it would be interesting to know if this is likely to be the extent of the sag given that it has already happened (not sure how these beams act over time)?

[ausdesign]

Good news OBBob.
I encounter design & load issues 5 days a week (7 according to my wife) & not begrudging an engineers livelihood I have a problem justifying fees of $400 or even $600 for simple computations.
If there is an engineer out there who is interested in the occasional work & is set up to be able to provide the appropriate 'form 9' - i'd like to hear from them.

[OBBob]

Rightly or wrongly I did the design myself using the span tables and software freely available from the manufacturers. Then I had it certified including a 'form 9' from a Melbourne Structural Engineering firm. Cost about $200 I think.

[thebuildingsurv]

Form 9 thats a new name for it, only seen reg 1507 certificates since Building Regs 2006, never seen a form 9, makes sense to call it that now it doesnt it.

[OBBob]

Sorry ... should have said Form 11 not Form 9. Also the approval was granted in 2005, which may make a difference?

Either way, the Building Surveyor was happy with is and I got the approval, which is what matters I guess.

[ausdesign]

I was the one to refer to "Form 9" instead of correctly to Form 11 OBBob.
Form 9 goes back to pre UBR's & I think the Form 11 is now called 'Certificate of Compliance' - maybe someone with knowledge can confirm this.

[pawnhead]

added- i lost track of the post but someone mentioned a beam sagging under load - this will never happen if the beam is designed correctly.

If it's timber then it's going to sag. From the Glamex website http://www.glamex.com.au/index.html Their precambered beams have a radius of 600m, and it says that after one week of loading they become straight. From their tables, a 4.8m span will have a precamber of 4.8mm. That's about what my Hyspan has sagged after a couple of months of roof loading. I didn't get my Hyspan with a pre camber, in hindsight I suppose I should have but you're kidding yourself if you think they won't sag so long as they are "designed correctly". Even steel beams sag under load and they're often pre cambered as well if it's crucial that the finished product is straight.

Pawnhead ... has the unfortunate issue above in this thread with a 5mm sag prior to all the load being on the beam. He hasn't really asked for help

I'm not asking for help because I don't need any. I've planed the ceiling joists straight and the Hyspan will be boxed in after the doors are hung dead level. I'm allowing 20mm adjustment for any future sagging, but I doubt that it will go anywhere near that in the next 100 years. I reckon it might go another 5mm tops, so I might precamber the bulkhead around the Hyspan. It's not a problem anyway. 5 or 10mm is nothing.

If you don't want it to sag then put in steel with a pre camber, but if you put in timber then it's going to keep moving throughout its life to some extent, depending on the design. That's why timber houses creak and quite often new timber houses get minor settlement cracks.

[OBBob]

Thanks pawnhead. It's not such an issue for me because there are no doors etc. under the beam. It's all a learning experience, we'll see how it goes.

Just for interest sake ... was just in Denmark a few weeks ago and there are soem amazing old buildings with equally amazing sags in their beams!! Of course they are hundreds of years old and still standing.

[ausdesign]

I stand rebutted Pawnhead.
Maybe I should have said - If designed correctly the beam will not sag more than the deflection limit permitted under AS1684.

[pawnhead]

Just for interest sake ... was just in Denmark a few weeks ago and there are soem amazing old buildings with equally amazing sags in their beams!! Of course they are hundreds of years old and still standing.

That rings a bell. Both my parents are Danish so I've got a bit of Viking in me. They were more famous for their seaworthy boats than their saggy beams though .