# Traditional timber framed mezzanine for industrial unit



## ejtrent (12 Oct 2016)

Hello all!

My names Elliott and I'm a furniture maker down in Bournemouth and I'm just about to move to a bigger workspace (woohoo!) 

A couple of friends are joining me to work and we've secured an industrial unit that's around 800sqft, but the best thing about it is is 6m high! So to take advantage of this we would love to put in a mezzanine floor to to give us an extra half of space. The rough size of the workshop is 8mx8m so we want to put in a mezzanine that's 8mx4m.

Of course it's easy to go and buy a steel one, but they dont half look boring! We are looking to expand into doing some traditional post and beam framing as part of our overall offer so would love to use this as a chance to create an exhibition piece for the workshop - for practice and for when clients come by.

So here's the design of the frame, all of this design is based on knowledge read from Jack Sobon's wonderful book (https://www.amazon.co.uk/Timber-Frame-C ... 0882663658)

Ok so heres the run down:

DETAILS:

6"x6" timbers on the post, beams and cross beams,

Then 8"x2" floor joists house in the beams with a half lap and screw from above (through joint)

Posts are 4m apart in all directions so the joists span 4m, joinery is all traditional post and beam, so mostly mortise and tenon, through tenons where possible,

Long beams Are scarfed jointed over the central brace (as per my reading in my timber frame book) then the posts have tenons on the top into the long beam,

Cross braces are placed 6" below the top beam to space out the mortises, to stagger the joint so I'm not taking out too much wood in one point (again as per reading from my timber frame book)

All mortise and tenons are let in to the wood with additional shoulders for strength, same for the braces, everything pegged wit oak of course

Al the beams will be *Fresh cut Douglas fir* and the floor joists will be standard cArcassing.

And the top will be a simple 18mm chipboard

So here is the sketchup ive made so far:























Thanks so much for your input guys, just wanted to see if you think it's built up to standard!

Elliott


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## skipdiver (12 Oct 2016)

I would question 4mt spans with 8"x 2" if you are putting heavy stuff up there.


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## ejtrent (12 Oct 2016)

Thanks Steve, 

Yeah the 8x2 is right on the limit of regs so maybe 10x2 is a better bet!


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## skipdiver (12 Oct 2016)

Depends what you are planning on putting up there, but from experience of a similar job at a mates double glazing firm, they piled everything up there "out of the way" and didn't bother to spread the load around evenly. the floor started to sag slightly and i had to go back and sort it. Easier in the long run to over-engineer from the start. I would also make sure that the half laps are beefy and you will need at least one set of noggins down the centre, which your drawing doesn't show. Ignore me if you already knew all that.


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## ejtrent (12 Oct 2016)

Yeah at the moment the joinery on the joists is the only thing that's concerning me, as I feel the frame itself seems to be over engineered enough?

It will be another workshop level, no heavy equipment but essentially 4 sewing machines and a large assembly table (my brother who is moving with us is a bag maker)

Is this kind of full housing the thing to go for? Scalloping into the joint?

https://encrypted-tbn3.gstatic.com/imag ... pU3Ug12L5e


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## ejtrent (12 Oct 2016)

This kind thing is what i was thinking..


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## Chrispy (12 Oct 2016)

Don't forget you will need a safety rail, and a stairs for access.


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## skipdiver (12 Oct 2016)

I wouldn't comment on joints of that nature as i am more of your big nail and joist hanger type. Never done any post and beam construction but i'm sure someone will be along with some pointers.


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## ejtrent (12 Oct 2016)

Thanks Steve, and Chris - it will definitely have them!


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## skipdiver (12 Oct 2016)

A quick internet search threw up a pegged tusk tenon which looks the type of joint for this project but as i say, i'm no expert.




http://timberframehq.com/tusk-tenon-two-ways/


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## ejtrent (13 Oct 2016)

Further brainstorming...

As height of the floor isn't crucial (over 6m ceiling) I was thinking potentially we could put on the floor joists more like a deck.

So make 25mm deep housings on top on the 6x6 plate and run them straight on top - with and detail for aesthetics - that still leaves 5" under the joists


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