Glue for pressure-treated wood?

[joasag]

Planning to join 2 pieces of 45x145 timber to make 1 piece of 90x145.
Is there a good glue to use for this, of course together with several 6x80 C4 construction screws.

Thanks!

 

[Pjosk75]

Polyurethane adhesive is suitable to use as it depends on moisture to cure. Which newly pressure-treated wood usually is, meaning moist.

 

[AG A]

I believe that it is Sättlim for indoor and outdoor constructions that is preferable. However, the wood should not be too fresh, it needs to be a bit drier. But you have probably already understood that.

 

[prototypen]

Why glue, the glue doesn't add any better load-bearing capacity vertically, although it becomes stiffer sideways.
Since it's treated, it's probably outdoors, and my first choice is polyurethane, but you need to screw tightly as the glue expands significantly.

Protte

 

[Dan_Johansson]

I tested regular wood glue for outdoor use and pressure-treated wood a few years ago...
Glued two decking pieces together, full coverage with glue and good pressure.
They held together for a little more than two years outdoors...

 

[joasag]

Thought the glue made it stiffer and required fewer screws? But maybe it's unnecessary if you need the same number of screws?

These are 3-meter beams that need to be joined. How many screws are suitable?
Will 4 pieces of this type 6x80 be enough: https://www.toolab.se/fast-traskruv...sbruk-hog-kvalitet-och-korrosionsbestandighet

Alternatively 6-8 pieces of this type:
https://www.biltema.se/bygg/fastelement/traskruvar/traskruv-6-x-80-mm-c4-100-st-2000061401

 

[Dan_Johansson]

What is the purpose of doubling a rule at such a short distance as 3 meters?

 

[z_bumbi]

Why glue, the glue doesn't add better load-bearing capacity vertically, it does become stiffer sideways though.
Since it's printed, it's presumably outdoors and my first choice is polyurethane but you have to screw tightly because the glue expands a lot.

Protte

I usually clamp and then screw.

 

[prototypen]

If you're gluing with PU, you'll probably need 2 screws for every 30 cm, so that would be 20 screws for a 3-meter piece.
Is the decking going directly on the 145s?

Protte

 

[joasag]

If you're going to glue with PU, you'll probably need 2 screws every 30 cm, so that would be 20 screws on a 3-meter piece.
Will the decking boards go directly on the 145s?

Protte

Then I'll probably skip the PU glue, it's a bit too many screws. It's for a pergola and 2x45 is mostly for appearance, so many screws don't look good.

If skipping the glue, how many screws are appropriate?

 

[AG A]

Then I'll probably skip PU-glue, a bit too many screws. It's for a pergola and 2x45 is mostly for appearance, so many screws don't look that good.

If you skip the glue, how many screws are appropriate?

But where on the pergola are these 90x145 meant to be used? I suspect they're for the posts. But regardless of where they're used, a single 45x145 will hold more than well enough. Double is solely for aesthetics. If, and which glue you then use doesn’t matter because it's not needed anyway. But if you still want to use it, it should be something that can withstand an outdoor climate, PU or Sättlim. The number of screws doesn’t really matter either. Ultimately, just so it holds together. 8 is what I would have used.

 

[hempularen]

Instead of most screws, you can use skruvtvingar.