LVL for decking bearers and joists - use with Kreg Deck Jig

[CodeFox]

Hi everyone,

I have decided to go ahead and use LVL for the bearers and joists on my replacement verandah / deck for a large number of reasons, but I am concerned that the joists may split since I am screwing into the "side grain". I will be using the Kreg Decking Jig to hide the screws. This jig pre-step-drills the decking bord, but doesn't pre-drill the joist - the screws are the type with the self-drilling head.

I am concerned that not pre-drilling the LVL may cause it to crack / delaminate and allow moisture between the layers. Does anyone have any experience with this?

Link to deck jig : https://www.kregtool.com/store/c24/deck-jigtrade-and-accessories/p263/deck-jigtrade/
Link to screws : https://www.kregtool.com/store/c24/deck-jigtrade-and-accessories/p175/protec-kotetrade-deck-screws--700ct/

[CodeFox]

I can't work out how to delete this thread ... I have just got off the phone with my local timber yard and they have convinced me that I shouldn't use LVL for outdoor use - even though there are a number of threads on these forums that say that it is good stuff to use. I will be using treated pine rougher headers instead. It works out a lot cheaper too, and hopefully won't have the splitting issues I was concerned about with the LVL.
... now to go spend 4 years of savings on a truck load of timber ...

[TermiMonster]

You've got to used treated LVL's (H3 for above ground, but I stand to be corrected on that.) a timber merchant should be able to tell you that.
As to that screw system, I am not familiar with it.
TM

[Bebbo]

100% no way would I use lvl outside. Look at scaffold lap boards. They're lvl and never last.
Treated pine would be the go.

[rwbuild]

H3 treated pine with Protectadeck membraine on top between decking and joist, wasting your time if you dont

http://www.bunnings.com.au/protectadeck-45mm-x-25m-pvc-joist_p0915409

[CodeFox]

H3 treated pine with Protectadeck membraine on top between decking and joist, wasting your time if you dont

http://www.bunnings.com.au/protectadeck-45mm-x-25m-pvc-joist_p0915409

Awesome, I haven't seen that stuff before. I'll duck down to Bunnings and have a look. Thanks.

[Bebbo]

H3 treated pine with Protectadeck membraine on top between decking and joist, wasting your time if you dont

http://www.bunnings.com.au/protectadeck-45mm-x-25m-pvc-joist_p0915409

I see the logic in this stuff. But after 10 years I've only ever been back to replace 1 deck and they insisted I put this on the joists and it rotted the decking boards out.

[CodeFox]

Yep, the sawmill just confirmed that for me. Apparently the decking membrane fills the gaps/ridges under the decking boards (that are there deliberately to allow air flow) and traps the moisture both between the bearers and the decking, causing it to rot out prematurely. I think I'll just paint extra preservative onto the tops of the bearers and see how it goes.

Thanks for your input everyone :)