How do you join a timber bearer to a timber post?

[jaysay]

Hello, 

I am new to the diy building world and I'm sure I'm going to sound like the novice I am but we all must start somewhere.

I am building a 3 x 2m deck. I plan on digging 9 piers and attach 90 x 90mm posts using stirrups. I then plan to lay 190 x 45mm bearers in a 3m continuous span across the posts. I have three questions:

1. Does all this sound 'normal' so far? I have read a lot of people nailing two bearers together but I think that sounds like over kill?

2. I would rather not notch out my posts to support my beams, after all there is a lot of them and I am worried that I wont be able to keep them all level. Can I simply attach them using this? https://www.bunnings.com.au/pryda-30-x-0-8mm-x-30m-strap-brace_p1072800

3. At some point in the future I would like to extend the deck to the side so it becomes a 6 by 2m deck. I was hoping to place the bearer 45mm into the post, leaving a 45mm gap from the end. When I attempt the extension some time in the future I would then slide another bearer into the space and connect the two bearers using this https://www.bunnings.com.au/pryda-strap-nails-50-x-100mm_p2430030 . Does that seem safe?

Thanks for all your guidance, 

(Also, if it matter, the deck will be 990mm above ground level and my piers are 700mm deep)

[MitchellMc]

Welcome to the Bunnings Workshop community @jaysay. It's wonderful to have you join us, and many thanks for your questions about connecting timber.

You are definitely on the right track, and it is great that you are asking these questions before you start. A 3m span with 190 x 45mm bearers supported on posts is very normal practice for a small deck. People often double up bearers when they are carrying heavy loads or spanning further distances, but for a 3m span single bearers of that size are more than adequate.

When it comes to joining the bearer to the post, the simplest and strongest method is to bolt them together rather than using strapping. Strapping like the Pryda brace you linked is not designed to carry vertical loads, it is mainly for bracing and holding members in place against sideways movement. A better option is to drill through the bearer and post and secure them with large coach bolts, washers and nuts. This gives you a solid, stable connection and avoids the need to notch the posts.

For your plan to extend the deck in the future, it would be more reliable to butt the new bearer alongside the existing one when you extend, and then bolt the two together through the post. That way, you maintain a continuous and strong connection rather than leaving a gap and relying on straps to tie them. If you line the new bearer up carefully with the existing one, the extension will be much easier to integrate.

Since your deck will be almost a metre above ground, it is worth making everything as strong and secure as possible. Bolting your bearers to the posts is a straightforward method that gives you a very stable frame and peace of mind for both now and when you expand the deck later. I'd also recommend you contact your local council before you start to ensure you don't require permission due to the elevation. Also, you might need to consider handrails due to the height.

Please let me know if you have any questions.

Mitchell

[jaysay]

Thank you for your response.

I am just wanted some clarification about how to use the coach bolt. If the bearer is sitting directly on top of the post how can I screw the bolt through both the bearer and the post? I thought I would have to notch out the post to place the bearer beside yet supported by the post in order to use the bolts?

Perhaps I can add two of these and screw the bolt through them?

https://www.bunnings.com.au/carinya-350-x-125-x-5mm-galvanised-mending-plate-bracket_p3961591

I would use all four of the bottom holes to screw into the post. I would use two of the top into the exiting bearer and then in the future when I add the new bearer I will attach it using the remaining two holes?

[MitchellMc]

Yes, you would need to notch the post to utilise bolts @jaysay. For a bearer sitting on the top of a post, you'd need to use nailing plates or brackets.. However, since a bearer is typically thinner than a post, there's no great way to do that.

The best technique is to notch the post and have the bearer sit within it on the side, secured by bolts.

Mitchell