Table top - will this work?

[SarahJ (Sarah Jones)]

I want to make a desk top to fit in a bay window for two people to work at, in a sort of squashed kite shape to match the angles of the bay.

I have worked out the shape and size I want it to be and a rough pattern for joining the planks, but my question is, will this work? The planks I have are 25mm thick rough sawn and I’m thinking they might be too thin once they are planed and squared to be strong enough to make such a big surface area without some support. The size I want it to end up is roughly 900mm front to back and 1600mm side to side. I want to put it on hairpin legs if I can get away with that. If that won’t work, what could I add to make it more solid? Some kind of shallow frame underneath, or a bar running side to side? The wood I have is mostly walnut, some zebrano. Thanks for any advice or suggestions.

[crafty_creator (Sally Brown)]

You say it will be a desktop - what would be on the desktop ?

If you are in the realms of heavy “kit” then it is possible your planks might be too thin, but if it will be just writing or something light duty you might be alright.

Personally irrespective of purpose, I would probably try and construct a frame for under your planks (with mortise and tenon joints) to match the outside shape with a couple of cross braces front to back. That would strengthen everything and prevent the desktop flexing if weight is added by spreading the load.

Don’t know if that helps - only my opinion !!

[SarahJ (Sarah Jones)]

Thanks Sally, that sounds like very sensible advice. I’ll be using it for office work and nothing heavy, just laptops and screens. I will think some more about a frame.

[Sean (Sean McCarthy)]

Very cool design, reminds me of a parquet floor

Personally I’d advise building a bit of a frame underneath just for peace of mind if nothing else - I built a desk about a year or 2 ago and skimped on structural support underneath and still kind of regret not doing that. Always nice to know something is good and sturdy if you’re going to be using it on a daily basis.

[Ryanf (Ryan)]

This will be such a good use of space. I’ll just echo what everyone else has already said. Only thing is if you build a table, always consider that people could potentially stand on it or climb on it, so design for that eventuality.

We have a domino at the space now, which will give you great support across the pattern. After prep, you’ll probably be looking at around 20-22mm finished dimension. I’d be inclined to weld up a 20mm square tube frame and just double the wood thickness around your edges to hide the frame. Essentially making the tabletop look 40mm thick.

[SarahJ (Sarah Jones)]

Thanks Sean and Ryan, that sounds like great advice. I’ve never tried any welding but like the idea of not adding too much extra bulk underneath. If I make a wood frame, how deep do you think it would need to be to give the strength it needs? I have a thick oak board I could rip into strips.

I think I’ll make a mock up version in ply to make sure the shape I’m imagining will work in the space. At the moment I’m working from home on an old oval gate leg table which is pretty but very awkward. So even a ply version of this shape would be an improvement on the current arrangement.

[crafty_creator (Sally Brown)]

Been thinking about this a bit more.

A follow up question -is the plan that it will be freestanding or attached to the wall in the bay ? With a brace under the frame that would give you a fixing point to the wall if needed.

With regard to frame I have attached a picture of a corner shelf unit I made out of American yellow pine; I see the frame for your table being constructed in a similar way to how the sides were made. This was made using a Trend Mortise & Tenon jig so the angles were not an issue; the wood was 25mm thick I think with 50mm wide strips. Having that underneath would certainly spread the load and would give you something to attach the top to from underneath.

I was going to mention using the Festoll Domino that I know has arrived at the Space to make loose tenon joints for a frame. Do you see the top being installed in separate strips ? I think I would consider biscuit jointing them together to make a wider board after I had laid out my design and trimming that down to fit the space. That would even out the surface rather than having the flex of multiple smaller planks. Only issue would be final sanding might be awkward with a wide board.

[tomnewsom]

Assuming the three equal-length sides are fixed to the wall, with the way you’ve laid out the planks you can get away with a single rib and a single leg I reckon. It’d be slightly off-center but you could hide that.

[RichM (Rich Maynard)]

The herringbone design looks great but I think you may have problems with the timber moving, especially if it’s a bit green. The planks will shrink across their width but not length so gaps will open up in your desk.

Something to watch out for!

[SarahJ (Sarah Jones)]

Oh that’s a good point about the wood movement. It won’t be fixed to the wall as the window is quite low. The shape is just to fit the maximum working area for two people into the space - a normal shaped rectangle desk would be a bit cramped for two. Plus I like facing down the road instead of directly across the street.

The boards have been stored in the room where the desk will be for years and the temperature in the room doesn’t vary all that much because it’s north east facing. @RichM do you think that would make them stable enough? Or still too much chance of unequal movement & cracking? @tomnewsom that’s a very nice drawing, thank you!

[SarahJ (Sarah Jones)]

Thank you. These shelves are lovely.

[crafty_creator (Sally Brown)]

Another thought ! Some wooden garden furniture is made in a way that I think would assist here, where a “frame” is incorporated as part of a top.

Found this picture of a table to illustrate.

https://www.sustainable-furniture.co.uk/1-2m-teak-octagonal-folding-table?gclid=Cj0KCQiApb2bBhDYARIsAChHC9sqlfBwzIaE0rqN1eCdda9304aqCjTWe84eF8ReyamcfP71DMcuVu0aAiEHEALw_wcB
https://www.sustainable-furniture.co.uk/1-2m-teak-octagonal-folding-table?gclid=Cj0KCQiApb2bBhDYARIsAChHC9sqlfBwzIaE0rqN1eCdda9304aqCjTWe84eF8ReyamcfP71DMcuVu0aAiEHEALw_wcB

If you look at the close-up, the frame and cross braces are made of thicker timber so give strength and stability. That removes the need for a supporting frame under your boards. They would have a rebate routed in to them the same thickness of the planks for the top. With the planks glued into this rebate, I think that would remove any flexibility in the table top, it also gives the impression of a much thicker table.

I’m thinking more about your project than my own !!

The shelves are probably the most challenging thing I have made; I like them too. In my opinion the picture doesn’t do them justice !

[Jonty_Bottomley]

Seconding @tomnewsom‘s suggestion.
You could also put a sheet of ply on top of whatever framework / battens and leg option you go for and screw / glue to that and run some thin bits round the edge to cover the ply and exposed end grains.
That would do a chunk to mitigate movement.

[SarahJ (Sarah Jones)]

I wondered about a sheet of ply. It feels a lot like cheating but that doesn’t matter if it works!

[TonyP]

re. making a mock-up version… I made a mock-up of a table that I’m planning (not wholly unlike yours - a sort of fan shape - imagine the three shorter sides of yours being one curve) from thick corrugated cardboard, mostly old boxes, with a few strips of scrap wood underneath to keep it rigid.

As I was planning round legs, I used those large diameter cardboard mailing tubes, so it cost next to nothing.

It didn’t tell me anything about appearance, construction or strength, but did give an idea of whether the shape and size worked for me before getting into anything that resembled hard work…