Thread: Over building?

I feel your pain as someone who has come from carpentry and is a self/book/youtube/forum- taught furniture maker. Furniture is usually not load-bearing (other than supporting its own weight) and so choosing the dimensions of materials used depends on aesthetics as well as construction method, purpose of the item etc. Usually too much weight on a shelf, for instance, will result in sag rather than collapse of the whole thing. I have seen 'span tables' for shelves, but that aside so far I'm working on a combination of following convention, instinct and luck.

Hmm.. That was probably not helpful. Good luck to you anyway!

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See the examples of over building above. With a very happy Customer. This project was made from roofing timbers salvaged from work sites (with permission) within the suburb. Connected to the wall with threaded masonry bolts. 8x 200kg load bearing 75mm type.

Sometimes when I make something, I will guesstimate what will be needed with regards to joinery and fixings during the planning stage and then I will go off and build it that way. But things don't just start from raw material to a finished product with no steps in between. As I am building it, I will be constantly flexing and stressing joints trying to replicate the real world situations the joinery will be put under. If something starts to creak or I can feel movement in the joint, I will go ahead and reinforce or redesign the joint.

I am just finishing off a batch of serving trays, something I have made a good number of in the past. But this time I decided to save some material for the bottom panels by resawing a piece of 23mm tassie oak down the guts hoping to end up with a flat bookmatched panel ~9.5mm thick. They ended up being ~6.8mm thick due to some severe cupping while resawing, which I thought would be way too thin. But since timber doesn't grow on trees I continued on knowing that I can check things out almost completely before committing myself to the design. Once I had the bottom panels in the grooves of the four sides, the bottom panel didn't flex at all/much with 30kgs on top of it. So I was good to go and out came the glue bottle to commit myself to the design.

If you want to quantify anything meaningful use as1720.1. Learning curve might be a bit steep initially for non technical people but once you work out all your units it's pretty easy.

Local library etc might have a subscription service for you to obtain a copy.

DO NOT design anything structural/important/large without the help of a qualified professional

Originally Posted by chris0375

DO NOT design anything structural/important/large without the help of a qualified professional

I agree in principal, but arent so sure if they're mostly a help or a hindrance. Theres an awfull lot of things that have stood an awful long time without any input from a "qualified professional" and most of them wouldnt get building approval today. Architects give us things of great beauty - though beauty is often in the eye of the beholder- that are impossible to build. Engineers give us standardised boxes to live in and Ikea type furniture.

It aint that hard to build a timber house/shed/bridge/chair/table/bed that'll last, and most "design professionals" truly do not understand timber: my experience is that an experienced chippie or cabinetmaker who works with the material is a better judge of fit for purpose then any of them. Personally I think the reliance on qualified professionals is mostly driven by insurance companies. Not to say that I dont get the "why" of that, but I also see the limitations that mentality creates.

(I'm trying to get approval on a large span timber framed shed ATM, and the fact that I can stand in a shed of similar design thats stood through every cyclone for the last 80 years doesnt mean a bloody thing apparently)

I'll often get an idea in my head - such as for bunk beds - and will will basically just square dress the timber stock and make working joints at the height & locations I want them.

Then I'll dry-fit it all together, with the bulk of the stock untouched, apply blue painters tape to mark out the lines on the stock and stand back a few metres for assessment until I'm happy with both the lines AND the structure.

Break it all down and machine the stock to suit.

Of course, this does mean some jiggery pokery as one has to work around already predetermined joints and sometimes my positioning is a bit inconsistent. Still, I usually end up with what I want.

It's better to use this approach for a prototype and then use the more traditional approach (machine the rails/stiles/etc first and then make joints) for subsequent copies, but that's really only practical for a production run.

Originally Posted by CCS

Hi all,

I have a tendency to want to over build everything. In particular using timber way bigger than needed thinking bigger is better/stronger. Does anyone have any pointers/tips/resources which can assist me in general furniture building timber sizes?

I built my son a loft bed. On inspection by multiple ppl the comments have been 'that's build like a brick sh*t house', that's going to last forever, that's staying in the house when you move isn't it? Is that a mezzanine floor or a bed? and so on...

I have now started making my son a fold down table for under his bed and the top is 30mm thick, butcher block style, from recycled hard wood pallets. It weighs a tonne. As such my original plans have changed multiple times and i now have legs for it... Argh, not my original intention.

My lack of knowledge and engineering skills is disenfranchising and i am struggling to want to get back to task at hand now...

Any pointers will be warmly welcomed.

Thanks.
Headband warrior.

there are lots of plans out there for study tables. Most of the good ones use a top no thicker than about 19 mm.

Originally Posted by John.G

I agree in principal, but arent so sure if they're mostly a help or a hindrance. Theres an awfull lot of things that have stood an awful long time without any input from a "qualified professional" and most of them wouldnt get building approval today.

It aint that hard to build a timber house/shed/bridge/chair/table/bed that'll last, and most "design professionals" truly do not understand timber

I guess my comments were more to do with the use of codes and standards without experience.

Yes I agree a carpenter or cabinetmaker is going to be better for stuff like joinery and furniture. They will have far more experience dealing with the unique properties of timber.

Houses stand up because carpenters rely on span tables that an engineer developed.

Hi all,

Thanks for the input. I am a safety professional and used a 'common sense' (I know i shouldn't have said that) approach. I.e. If it doesn't move and can support me then it was well strong enough for my boy to use. I have since completed the table and have it installed. He hasn't seen it yet and this is the surprise for this weekend.

I will be consulting with the forum in the future for all builds as i find this is a great source of knowledge which would be stupid not to tap into. The next project will be something much smaller, photo frames, kind of done this whole learning wood working stuff in reverse hey? Big structural semi-floating loft bed - table - picture frames... LOL.

Again, thanks for you input.