2.8m Long Table; 4 or 6 legs?

[Togalosh]

Evening Gents,
I am to make a long slender farmhouse style dining table from oak & I would appreciate your help with 1 or 2 aspects of the design please.

The table is a copy of what I made years ago but a lot longer.. almost twice as long. The table top is to be 35mm thick with bread board ends & maybe 1 bread board in the centre to aid assembly on site as my van isn't 2.8m long inside. Besides at 2.8m it'd mean a lot of heavy lifting ( I was told years ago that I am no spring chicken).

The skirts/rails (?) are 100mm wide x 35mm thick which will be double haunched M&T's into 90mm2 legs. The top is held in place by oak tabs (?).

Excuse the poor drawing.. it's my 1st go at digital plans.

View attachment NHI Table 1.pdf

So my main concern is that with only 4 legs the 2.8m table top will sag in the middle. I am I correct in thinking it really needs 6 legs or should it be fine as drawn?

4 legs looks better so if there is a chance of sagging then can I add more support rails underneath (like a torsion box).. or maybe something like an "i beam" running the length of the top?

Also; if my van is not long enough how do I assemble the base on site - can I use sliding dovetails instead of M&Ts ?.. maybe I should hire a bigger van.

As ever your help would be greatly appreciated.

Togs

 

[Togalosh]

View attachment NHI Table 4 legs.pdf
or this more like..

 

[MikeG.]

A centre breadboard/muntin(?) would really weaken this. That would take all of the structural strength out of the table top, meaning that the only longitudinal strength came from the skirt. I would have a rethink on that 'twere it me. Secondly, do the legs need to be at the corners? If they were inset one place setting from each end then that really horrible central leg idea would be completely unnecessary. Have you worked out how a central leg would go in relation to the place settings and chairs?

Personally, I'd be pretty confident that 135mm to structural depth was plenty for that span. However, I would be carefully analysising where the chairs would be going, and then I'd move the legs inboard, and worry no more.

 

[Jacob]

Yes, bring the legs in a bit so there's say 500mm overhang and just 1.8m between legs. It's quite common and traditional with big tables. Also convenient - no table legs at the end getting in the way of chairs.
I wouldn't bother with breadboard ends - just added complication.
The secret of designing common items like this is to have a very good look at some examples, otherwise you are re-inventing the wheel, and risk getting things wrong.
I'd also bring the legs in to make a bigger overhang on the length, say 80mm or so.

 

[Just4Fun]

My dining table is 3m long and has 4 legs (at the corners). The top is 45mm thick with no breadboards. There is no sign of any sag.

 

[Jacob]

Pictures here, 2.5m table
http://interiorboutiques.com/product/an ... use-table/

 

[Togalosh]

A centre breadboard/muntin(?) would really weaken this. That would take all of the structural strength out of the table top, meaning that the only longitudinal strength came from the stretchers. I would have a rethink on that 'twere it me. Secondly, do the legs need to be at the corners? If they were inset one place setting from each end then that really horrible central leg idea would be completely unnecessary. Have you worked out how a central leg would go in relation to the place settings and chairs?

Personally, I'd be pretty confident that 135mm to structural depth was plenty for that span. However, I would be carefully analysising where the chairs would be going, and then I'd move the legs inboard, and worry no more.

Ah, yes.. now you have pointed it out I can see that the centre board is a weakness. It's looking more likely I need a bigger van. I left it in beause I was sure 6 legs was the best option.

I put the legs 75mm in from the edge as it leaves 630 per person..again based on the awful 6 leg plan... but 600 would do at a squeeze.

Thanks.

 

[Togalosh]

Yes, bring the legs in a bit so there's say 500mm overhang and just 1.8m between legs. It's quite common and traditional with big tables. Also convenient - no table legs at the end getting in the way of chairs.
I wouldn't bother with breadboard ends - just added complication.
The secret of designing common items like this is to have a very good look at some examples, otherwise you are re-inventing the wheel, and risk getting things wrong.
I'd also bring the legs in to make a bigger overhang on the length, say 80mm or so.

My poor drawing does not show the overhand of 75mm each way but I can defiantely remeasure to bring them in more along the length. I haven't noticed the legs interfering with moving the of chairs on my existing table.. but that's not to say they haven't...hhmm???

The bread boards are also for character along with hand cut dowels etc.. plus I like them & they are not that much effort to do.

I have spent a lot of time trawaling the web & looking under tables wherever I go & have seen both 4 & 6 legged examples but only 1 like mine & that photo did not show what I needed to see.

Thanks
Togs

 

[Togalosh]

My dining table is 3m long and has 4 legs (at the corners). The top is 45mm thick with no breadboards. There is no sign of any sag.

Ace ..Have you got a skirt/stretcher/rail M&T'd into the legs, how old is your table ?

All the photo's of long tables had thicker looking tops.. not sure I have the stock to do 45mm though !..

Thanks
Togs

 

[Togalosh]

Pictures here, 2.5m table
http://interiorboutiques.com/product/an ... use-table/

Ha .. that's it. It's stood the test of time too & yes that extra overhand at the end looks good.
Nice one Jacob.

This is my original

 

[dzj]

A made a pair of such tables. 3m x 1.5m. Four legs, Oak, no breadboards.
(2009, where has the time gone, eh?)

 

[Racers]

How about a single central leg in the middle of a stretcher? it should be out of the way.


Pete

 

[Jacob]

Pictures here, 2.5m table
http://interiorboutiques.com/product/an ... use-table/

Ha .. that's it. It's stood the test of time too & yes that extra overhand at the end looks good.
Nice one Jacob.....

I wonder about the top - it's not as nicely made as the undercarriage - could be sawn off bread board ends, or even a new top with old boards?

 

[Just4Fun]

Ace ..Have you got a skirt/stretcher/rail M&T'd into the legs, how old is your table ?

There is a skirt along all 4 sides, attached to the top. From the outside it looks as if it is M&T'd into the legs but that is an illusion. Look behind and you will see that the legs are removable, held in place by a bolt and metal bracket, flat-pack style. I didn't make this table myself, I had it made as a custom size by a company who normally make flat-pack furniture, so I guess I got what I deserve. In reality it has been fine, with no racking, sagging or other problems so I shouldn't complain.

I have just been to measure it and the sizes are:
Top: 3000 x 1100 x 45
Legs 80 x 80 x 710 (to under side of top)
Rails are 75 x 25

One thing I had forgotten is that there are 4 cross rails (50 x 25) on the underside of the top, evenly spaced over the length. I am not sure what these achieve as they are not connected to the side rails and, at 900 long, they don't even span the full width of the table.

According to a date stamped on the inside of one of the rails the table was made 6 August 2006, which tallies with my memory of when we ordered it.

 

[Jacob]

.....
One thing I had forgotten is that there are 4 cross rails (50 x 25) on the underside of the top, evenly spaced over the length. I am not sure what these achieve as they are not connected to the side rails and, at 900 long, they don't even span the full width of the table.
....

They work the same as guitar sound board bracing download/file.php?id=75184&mode=view
keep a wide thin joined board flat and allowing for movement. Sound quality doesn't matter though!
It's common on round tables - very wide boards with a lot of potential movement, and allows for thinner boards

 

[custard]

I am to make a long slender farmhouse style dining table from oak
The table is a copy of what I made years ago but a lot longer.. almost twice as long. The table top is to be 35mm thick with bread board ends & maybe 1 bread board in the centre to aid assembly on site as my van isn't 2.8m long inside. Besides at 2.8m it'd mean a lot of heavy lifting ( I was told years ago that I am no spring chicken).

The skirts/rails (?) are 100mm wide x 35mm thick which will be double haunched M&T's into 90mm2 legs. The top is held in place by oak tabs (?).



So my main concern is that with only 4 legs the 2.8m table top will sag in the middle. I am I correct in thinking it really needs 6 legs or should it be fine as drawn?

I've made several tables at this length, four legs is perfectly adequate provided the side aprons rails are at least 30mm thick.

Your proposed six leg plan has a few serious problems though. You might get away with that centre joint for a few years in a very quiet household, but two or three house moves would definitely see that joint fail.

I suspect this is a case of the tail wagging the dog, in that the size of your van is dictating the design. I'd say build it full length with four legs, then just hire or borrow a bigger van.

 

[Togalosh]

How about a single central leg in the middle of a stretcher? it should be out of the way.Pete

Hello Pete,
That was my 2nd thought .. but again I dismissed it as no one else has done it... & that it also looks odd. Odd is what I usually like but something just didn't feel right... also if the floor isn't level then that'd lead to more wobbling.

Togs

 

[Togalosh]

[/quote]I've made several tables at this length, four legs is perfectly adequate provided the side aprons rails are at least 30mm thick.

Your proposed six leg plan has a few serious problems though. You might get away with that centre joint for a few years in a very quiet household, but two or three house moves would definitely see that joint fail.

I suspect this is a case of the tail wagging the dog, in that the size of your van is dictating the design. I'd say build it full length with four legs, then just hire or borrow a bigger van.[/quote]

Hello Custard,
You say a 30mm thick (side to side ? ) apron.. I thought the height (top to bottom) was the crucial measurement... What would you recommend for the height (top to bottom ) ?

You are correct in your opinion that the tail is wagging the dog.. I will hire another van & make the table as it must be made. I still have to carry the thing in by myself & they don't make gluten free wheatabix ..

Thanks
Togs

 

[Togalosh]

Pictures here, 2.5m table
http://interiorboutiques.com/product/an ... use-table/

Ha .. that's it. It's stood the test of time too & yes that extra overhand at the end looks good.
Nice one Jacob.....

I wonder about the top - it's not as nicely made as the undercarriage - could be sawn off bread board ends, or even a new top with old boards?

The top is surprisingly thin & the legs suspiciously coloured..

 

[MikeG.]

I'm wondering about your forum name, Togalosh. Is it based on the Southern and Eastern African boogie-man? I know him as Tokolosh, and we have a statue in the corner of the lounge be bought in, I think, Malawi.