How to build an outdoor dining table using Merbau decking?

[MorryM]

I've been tasked with building an 8 seater outdoor dining table for my daughter, I have no specific experience with this beyond some general woodwork/ construction projects but have access to most required tools except a jointer. As this will be an outdoor table, actually on a covered deck, I had planned on leaving a 3mm gap between boards so won't need perfectly parallel  edges.

Most online projects call for 25mm or 50mm planks but ideally I'd like to use merbau decking from Bunnings as it's a reasonable price and looks good IMO and  I've just completed a deck reno using 90mm * 19mm merbau and have some leftovers I could repurpose.

Anyway I guess my question is is 19mm going to be too thin or should I look elsewhere for 25mm boards * 140mm boards? I realise thinness is an subjective  concept but I'd like to make this setting  look good not just functional.

I had considered Bunnings 140mm*19mm merbau but was concerned about cupping with a wide thin board.

Any ideas much appreciated?

[EricL · Accepted solution]

Hello @MorryM 

Welcome to the Bunnings Workshop community. It's marvellous to have you join us, and thank you for sharing your question about using Merbau as a tabletop for an outdoor dining table.

I'm a big fan of Merbau timber and I think using it as a tabletop is ok. I've been meaning to make something similar but have not had the opportunity. 

I suggest applying the same rules when building a deck. The table frame should have joists at 450mm intervals or less depending on the size of the frame. Use proper decking screws with the recommended distance. You can even get fancy by using hidden fixings so that there will be no screw holes on the surface of the table.

This is a great opportunity to get creative with the tabletop, you can incorporate decking layout styles on the table in order to make it stand out. A good example would be put a picture frame around it or add breaker boards to add even more variety to the surface. You can even add patterns if you've got the time to do custom work. 

If the frame is built similarly to a decking frame, it should provide good support and will prevent the panels from twisting and warping. My best advice is to make sure to seal the top like you would a decking panel. This will protect it from the harsh weather and day to day use.

I've drawn up a sample sketch below to give you an idea of how you might be able to build it. Please note that the measurements are for reference only, make sure to adjust them to your needs.

Please remember to wear personal protection such as gloves, goggles and a mask when working on your dining table.

If you need further assistance, please let us know.

Eric

[MorryM]

Thanks so much for the comprehensive reply, I hadn't considered breaker boards as one of the benefits of Bunnings merbau is you select lengths rather than a random pack from some timber merchants but considering the length of the table I think it would look better  and help brealk up the palnky look of long boards.

I'll definitely do a picture frame border with rounded edges as I have to ustify buying routers track saws etc.

Any thoughts on 90mm vs 140mm?

Haven't really thought  about leg design, I don't want it to be rustic or overly fancy, clean and simple, maybe slightly angled  with appropriate scale would be ideal. I have quite a bit of left over hardwood joist material in 150mm* 50mm I was hoping to use.

[EricL]

Hello @MorryM 

Between the 90mm and 140mm decking, I prefer using the 90mm as it gives a compact appearance despite the fact that you are using more of the panels. It also gives the impression that its construction was more involved.

As for the legs, I suggest keeping it simple with like an inverted "T" with double supports and a moderately sized foot. This allows you to maximize the use of the table. You'll still be able to place a chair in front of the foot and use that area versus a leg that is close to the edge preventing you from placing a chair in that spot.

I've drawn a sample sketch below. Please have a look and tell me what you think.

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

Eric

[Jed1]

Hi Eric,

I have used your template for my own table and it looks great!

The only issue I am finding is that it seems to have a bit of a wobble that I am concerned about, especially as I have not fixed the decking on top as of yet.

Do you have any suggestions on what I could do to make it more stable? I was considering a metal pole of some sort as a stretcher but not sure how that might work.

Thanks

Jed

[EricL]

Hello @Jed1 

Welcome to the Bunnings Workshop community. It's marvellous to have you join us, and thanks for sharing your question about the outdoor table.

It's wonderful that you've been inspired by this project to create your own table. My apologies for the late reply and that I did not finish the plan. It was meant to be as an idea generator, and I did not realize that you would be using it as a full-on template.  

I've finished the drawing below and it includes the support struts that are supposed to be installed to give the legs rigidity. You are more than welcome to modify the plan if you feel that there is a better way to do it. This image was my original idea to support the legs at the time.

Please don't forget to post a photo update, I'm sure our members would be keen to see your table project. 

If you need further assistance, please let us know.

Eric

[Craig3]

Hi Eric,

thanks so much for the drawings - they have been a great help for my planning. I'm also planning to do a table top from spotted gum decking and pre-made metal legs (3400 * 1200, using 135*19 boards and 3* X metal leg set) . A couple of questions if you can help

I'm keen to have a low profile frame if possible to make it less visible under the table. What would be the best timber product to minimise the framing and what size would I need. What joist spacing would I need? All the span tables I can find online are structural.

I'd like to avoid fixings through the surface of the table and also avoid adding any additional height so I would be looking to fix the legs directly to the boards. What would be the best method to fix the boards to the frame and legs with the boards being 19mm thick?

Are breaker boards just for visual effect? I'm planning to build a picture frame and then just lay continuous boards within that, so they will span 3m +. Any issues with the long span.

Much appreciated. Craig

[EricL]

Hello @Craig3 

Thanks for sharing your question about building your own outdoor table. Due to the length of the table, I suggest using 70 x 35mm Outdoor Framing H3 Treated Pine - 3.6m. Using a smaller grade of timber might cause the assembly to twist and warp.

I propose keeping the typical deck framing spacing of 450mm as this will keep the panels from moving and twisting. Picture framing is a design choice, and you can choose to keep your table simple. If you decide to add a picture frame an extra piece of timber will need to be added at the long ends of the table.

Would it be possible for you to post a photo of your metal legs? This will give our members a chance to assess its configuration. We can then make a recommendation on how to fix the legs into place.

In the meantime, I've placed a sample image of your table frame to give you an idea of how you can assemble it.

If you need a hand posting the photos, please let me know.

Eric

[Craig3]

Hi Eric,

your advice is spot on as always and the design look just like I had in mind. Thanks for the advice on the framing.

I've attached a photo of the legs. They are 700mm wide so they would comfortably sit inside the frame to fix directly to the table if possible to avoid it being too high. The top bar of the leg is about 5mm thich and the decking I'm using is 19mm so I was thinking the easiest way would be to use a 15mm screw from underneath - I just don't know if that will be sturdy enough. 

Thanks, Craig

[EricL]

Hello @Craig3 

The decking panel will not be strong enough to hold the weight of the table frame. I suggest running another joist along the inside of the frame but in a horizontal manner. I've placed an image below to give you an idea of how to install it.

The new joist must be anchored to the ends and to the joist that is installed vertically beside it. This will spread the load when you attach the legs. Since the timber piece is only 35mm thick it will not raise your table too high and will be close to the proper eating level for a dinner table.

If you need further assistance, please let us know.

Eric