What size treated pine for bench seat?

Hello @Redboy65

Welcome to the Bunnings Workshop community. It's sensational to have you join us and thanks for sharing your question about building an outdoor bench seat.

Would you happen to have a sketch of the seat you are building? If you can please share a picture of that sketch, it will give our members a better idea of its structure. We can then make recommendations on timber size. If it is a three-seater or larger, I would suggest using the 90mm x 45mm, but if it is just a two-seater it might be possible to use the 90mm x 35mm. You can even technically use the 70mmx45mm if the spotted gum can provide extra support to the frame.

If you need a hand posting an image, please let us know.

Eric

https://www.workshop.bunnings.com.au/discussion/comment/48013#Comment_48013

G'day Eric, thx for getting back in touch with me. Please find attached Plan and Elevation diagrams for the design. Basically the bench seat is in an L-shaped config at the end of our decking balcony. It's going to consist of two frames "Small Frame" and "Large Frame". The frames will be made up of treated pine and the cladding will be spotted gum decking board (19mm x 86mm x 1600mm).

Hope this helps and once again, thanks heaps for your help.

Cheers,

Redboy65

https://www.workshop.bunnings.com.au/discussion/comment/86066#Comment_86066

Hello @Redboy65

Thank you for providing those detailed plans of your bench seat. I was initially concerned that you would have a very long seat, but now that you've shown me the plans, I suggest using the 90 x 35mm Outdoor Framing H3 Treated Pine - 2.4m for framing. It's not too bulky like the 90mm x 45mm, but it is strong enough to hold the weight of people sitting on it. My best advice is to drill pilot holes on both the frame and your spotted gum to prevent splitting the timber.

Let me call on our experienced members @JoeAzza, @Dave-1 and @Nailbag for their opinion on timber frame sizing.

If you have any other questions we can help with, please let us know.

Eric

https://www.workshop.bunnings.com.au/discussion/comment/108342#Comment_108342

Brilliant, thx heaps Eric ! I'll wait for the other replies in the meantime.

Cheers,

Redboy65

https://www.workshop.bunnings.com.au/discussion/comment/121448#Comment_121448

Afternoon @Redboy65

Love your plans 😀 Seriously nice and concise!

I prefer the 90 * 45mm pine 🙂 Mostly because I figure you will have characters flopping down onto a bench seat and that little extra cannot hurt 🙂 I also like @EricL's suggestion of pilot holes.

I built a bench seat with wheels and went with the larger sized supporting timber frame but looking similar (in my mind) to yours.

Outside timber lounge with wheels

If you "test" a smaller piece of timber in bunnings when you are purchasing what you want by having the span between two points and then slowly put your weight on it. if it bows go for a larger size if it dosnt then why not, problem solved 🙂

The last one id suggest is to oil your new seat as soon as possible and then set an aniversary/birthday on your ph (with a reminder the week before) to reoil it every year. We tend to forget that we should do it.

Dave

https://www.workshop.bunnings.com.au/discussion/comment/129688#Comment_129688

Thanks heaps Dave! Yes, I was definitely going to put pilot holes AND will definitely oil it! I will test the 90x35 and 90x45 for bowing when I pick up the timber tomorrow night. I figured the longest span without support is going to be approx. 700mm hence why I think the 35mm should be OK.

Thanks heaps for your guidance!

PS: Love your bench seat btw...gave me ideas about wheels !!

Redboy65

https://www.workshop.bunnings.com.au/discussion/comment/134874#Comment_134874

Hi @Redboy65

Please keep us updated with your progress, we look forward to seeing the start of your bench seat project.

Eric

Nailbag

Hi @Redboy65

Love your plans and I can't say I have much to add than what @EricL and @Dave-1 have already contributed. Except for the choice of timber! I'm on the other side of the bay to you and I have several spotted gum deck mostly exposed to the sun and weather. If I had my time again, it's the last choice other than treated pine. It looks awesome when first laid, but I can guarantee it will bow, split, and deteriorate rapidly even when coating with several layers of the best oil. I have already replaced boards within 5yrs and the last lot are already showing signs of deformity.

If you're looking for something other than Merbau, which is always a safe choice then consider Blackbutt.

Nailbag

https://www.workshop.bunnings.com.au/discussion/comment/48082#Comment_48082

Frame ready! A lot of learnings (😂) but overall happy with my first effort.

https://www.workshop.bunnings.com.au/discussion/comment/86287#Comment_86287

Good Evening @Redboy65

Brilliant! 😀 I would be happy with that for sure! Cant wait to see the cladding 🙂 Are you going to put it into place before cladding? It may end up pretty heavy to shift over once clad I am thinking.

Dave

https://www.workshop.bunnings.com.au/discussion/comment/86287#Comment_86287

Hello @Redboy65

Thank you very much for that update, the frame looks great! I agree with @Dave-1, it's best to put it into position before you start cladding it decking panel. Otherwise, it will weigh a ton be and be extremely difficult to lift.

Eric

Nailbag

Hi @Redboy65

Nice work on that frame and I also agree with that great tip from @Dave-1 in first positioning before cladding. You could still have all the boards pre-cut and pilot holed and even oiled in the shade of the shed.

If you still decide on spotted gum for the gladding then at least ensure you're paying for the real stuff and not Tallowwood. It looks very much the same as SG, but doesn't have the black streaks and spotting from Beatles common in this species during growth. With mills closing down, SG is becoming difficult to get and in consistent widths. So, Tallowwood is a cheaper alternative, but is often sold at the higher price as SG. I learnt this from a timber mill supplier.

When it comes to oiling, I am now a converted fan of Feasts & Watson water-based matt finish deck oil. I've only applied it to other peoples decks, but it's awesome. Great finish and doesn't leave the surface tacky for days even when fully dried like even Ingrain does.

Nailbag

https://www.workshop.bunnings.com.au/discussion/comment/108488#Comment_108488

Yes, absolutely agree, that was going to be my intention - to clad it once I put it into place! It's already very heavy to take up 3 flights of stairs!! Thanks for the advice guys, really loving the support I'm getting on this site!

Redboy65

https://www.workshop.bunnings.com.au/discussion/comment/48453#Comment_48453

@Nailbag,

Thanks heaps for the advice! Wasnt even aware of Tallowwood !! The SG I'm using is mostly our old removed decking that was lying around. A lot of it is warped as it's been sitting under the eaves of our house for a couple of years so really weathered. I've cleaned them all up but not sure how many of them are going to be useable due to the warping. Had I not had a lot of the SG left over to use, not sure I would have gone down this path. I really wanted to recyclye rather than re-purchase in bulk.

WRT to the oiling, because my holiday house is literally 500m from a surf beach on Phillip Island, the bench seat is going to be open to the elements and I'm actually contemplating painting rather than oiling. I know the finish will look nowhere near as nice BUT it will last longer and will remove the need to oil every year. Thoughts?

Cheers,

Redboy65

https://www.workshop.bunnings.com.au/discussion/comment/86314#Comment_86314

Evening @Redboy65

Oil 🙂 Oil all the way. Main reason is its not going to peel off. Yes you will have to do it every 6 months then yearly, but that close to the beach the paint would be doing the same. Well I do have a soft spot for oiling 🙂

Dave

https://www.workshop.bunnings.com.au/discussion/comment/108513#Comment_108513

Starting to come together !!

Starting to comer together! Haven't fixed the cladding just yet as it's taken me forever to find the "straight" pieces of cladding to use...nevermind trying to line up the mitre joints with warped pieces of timber !!!

https://www.workshop.bunnings.com.au/discussion/comment/121558#Comment_121558

Morning @Redboy65

With the bent slats right up to the worst bannana bends I have used a pair of ratchet straps to help me straighten them out. These have seriously not failed me and after fixing them to the backing timber have not shifted over the years. They bed in and keep their straight shape 🙂

Outside timber lounge with wheels step 2 towrads the bottom of the page shows how Ive used them. Ive also used it on my tall pricacy screen and that made life so much easier.

The seats look good and love the edge!

Dave

MitchellMc

https://www.workshop.bunnings.com.au/discussion/comment/129755#Comment_129755

That's looking great, @Redboy65! I can't wait to see the finished bench.

Mitchell

Nailbag

https://www.workshop.bunnings.com.au/discussion/comment/86314#Comment_86314

Stick to oiling I reckon @Redboy65. Weathered paint looks a lot worse in a shorter amount of time than weathered oil. To me anyway. Plus it needs to be sanded when repainting, where oil usually doesn't or very little. And as soon as you see it starting to fade off, then re-oil.

Nailbag

https://www.workshop.bunnings.com.au/discussion/comment/108560#Comment_108560

Slowly but surely....beaten by the weather yesterday !!!

JacobZ

https://www.workshop.bunnings.com.au/discussion/comment/121613#Comment_121613

Hi @Redboy65,

Nice work!

Your frame looks nice and sturdy, the natural colour of the decking looks fantastic and you've got some nice tight mitres that give it a clean finish.

I can't wait to see if finished once that pesky weather holds out and you can finish up.

Thank you for sharing.

Jacob

https://www.workshop.bunnings.com.au/discussion/comment/129790#Comment_129790

Afternoon @Redboy65

Loving those miter joins! 🙂 Its Looking good and will really be nice to sit out there and just watch life 🙂

Dave

https://www.workshop.bunnings.com.au/discussion/comment/134942#Comment_134942

Finally done ! Happy with my first ever attempt. Learnt a lot in the process....now onto the next project!

Thanks to everyone for their advice and encouragement, every little bit helped !!!!