Table max load estimate

[brave]

Hi..

I'm looking to make a table that I will place a mud oven atop. I'd like to minimise costs so am looking at pine if it is an option and will hold the weight.

I've done a mockup here:
ImageShack® - Online Photo and Video Hosting (http://imageshack.us/photo/my-images/100/woodoven100x75.png/)

The image isn't to scale and I was intending to place a third beam through the middle to support the table boards. The table will be 1.6m by 1.6m, and the legs will be 0.6m. All timber inc legs will be 100x100 and the table top boards 200x50. The legs are only short because the table will be placed on an existing raised deck which is sitting directly on a concrete slab.

With those measurements what load do you think it could comfortably hold whether pine or a generic hardwood?

[elanjacobs]

I'm no engineer but, if you put a centre leg in as well as the centre beam, I'd say that with a good glue and some long coach bolts it should comfortably hold the weight of a small car.

[Sam]

Yep, a leg right in the centre is a good idea. I'd make the apron 200 X 50 (200 vertical) and also have a 200 deep centre beam running over the central post.
Most timber framed residential floors with floor joists at 450 centres are designed to take 150kg per square metre (1.5 kPa)

Vertical bracing ie making an 'X' where you have the upside down 'V' would be worthwhile. That will stop the whole thing twisting as people lean on it or you vigourously stoke the fire !

[Trav]

Will the deck bear the weight? You mentioned it is sitting directly on top of a slab, but even a few cm gap between the decking boards and the slab could be an issue if the weight is not evenly distributed. If the legs go through to the slab it should be fine. Or if the decking boards are directly on the slab.

Have you thought about cutting an appropriate hole in the deck and building a brick base? Pizza ovens don't strike me as a particularly portable thing, so moving them from one house to another would be a challenge. I made a pizza oven (well, I made the base of a pizza oven - long story) and I ended building it up from wall blocks used to make retaining walls. They fit together nicely, can hold a huge weight and look really neat. I topped it with pre cast concrete slabs (which almost killed me to move), but you could use fibre cement and cast your own top.

Also, I'd extend the front of the table a bit in front of the oven. That way you have some space to put the oven door (if you have one), oven tools, your beer (if you like it warm) and a staging area for pizzas.

Trav

[Robson Valley]

Your "mud" might weigh some 1,500kg/m^3. For long lasting even heat, an IR thermometer will probably show 500C or better. I'd use some cheap, generic local hardwood but stop about 2-3 bricks short of the height I needed.
Might not even need mortar. Until they repeal the Law of Gravity, I don't believe the oven will float away.