How to attach bearers to stumps?

jeffl_au

I don’t have a framing nailer. Just wondering what’s a good way to attach a 2x(90x45) to a 100x100 stump.

is there some galvanized bracket that sits on the stump and fixes it to the bearer?

also… is there significant advantage in using galv stirrup vs a bitumen painted treated pine post?

thanks!

MitchellMc

Given the 90mm thickness of your two joists, you'd likely be best having them sit on top of the post. You can then use a Pryda nailing plate on either side to fix them to the post. You could potentially screw a VUEPRO 90mm Galvanised Tradies Bolt Down Post Support to the top of the timber post, but that's not a method I've seen used before. You just need to bear the weight of the joists and load, and that's done sufficiently by placing them onto of the post.

Using a gal stirrup would require fewer steps. However, they are designed to have vertical posts installed into them, so the holes for fixing your 90mm horizontal joists might be slightly off.

Please let me know if you have further questions.

Mitchell

jeffl_au

Thanks @MitchellMc

Might be a stupid question… but should I use a 90x90 stump instead? So it’s good he same width is my bearers?

MitchellMc

Could certainly do that @jeffl_au, it would suit the joists better. There shouldn't be any real need to use a 100mm post for joist support. Just make sure you grab an H4-treated 90mm post. Some of them will only be H3 for above-ground use.

Mitchell

jeffl_au

Hi @MitchellMc

That one is a lot more expensive than this one

https://www.bunnings.com.au/100-x-100mm-3-0m-post-h4-treated-pine-sawn-cca_p0051259

whats the difference? Do I need that expensive one?

thanks

Jeff

MitchellMc

@jeffl_au,

90mm posts are typically milled to a smooth finish, making them suitable for painting. They are also structurally rated, which allows them to comply with construction standards. 100mm posts are generally rough-sawn and more for landscaping purposes, like building non-structural retaining walls. It's the same issue as why you can't use sleepers to build weight-bearing structures, as they don't have a structural rating.

Unfortunately, according to construction codes, you can't use a non-structurally rated 100mm post for deck construction.

Mitchell