slab table help needed

[pinky]

I'm looking for some bookmatched 8/4 or 10/4 slabs at least 9 feet long for a table/bar. I'm using a pair of cast iron pedestals for the base. My question is the support for the slabs. Do I need support other than the pedestals. Looking for thoughts on the best route to take and avoiding as many mistakes as possible. Here are the bases.

[MichaelS]

Awesome idea Pinky, and those bases look great. Sourcing a spabslab currently for a desk myself, obligatory pics when complete


Michael

[BillMcD]

Three thoughts come to mind.
1 - Maybe turn the pedestals 180 degrees so that the third leg does not trip or otherwise interfere with people.
2 - Sounds like a heavy slab on heavy pedestals.  Don't want that beast coming down.  Tipping sideways looks a bit precarious if someone were to rest on the edge of the table top.  36"+ is going to overhang even the pedestal feet by enough to create leverage.  Not sure what to do about it, but maybe test the stability with a board.
3 - Use battens beneath a thinner, lighter slab.  Install them to permit expansion and shrinkage of the slab.  Sliding dovetails, slotted screwholes, etc.  Assuming you want to hide the fasteners and keep the top clean, the battens can be bolted to the pedestal.  I like that better than screwing up into the slab. 

In any case, this is going to be really cool.  Hope you get it in the right place the first time and don't need to move it too often.

[DonJuvet]

Don't worry about the length. Bring those in with a 16"-20" overhang and you will be just fine.
You will need something for the width unless you plan on joining the bookmatch edge together. 
(make it a good tight fit. 
weight is your friend in combatting the leverage advantage.

[pinky]

Thanks for the replies. I do plan on jointing and gluing the 2 pieces with a tight fit. I think I will bolt 1/4 plate steel maybe 10" wide x 24" long across the width with slotted or oversized holes to allow for movement. I have no concerns of tipping. These bases probably weigh at least 200 lbs each and the 3 legs or pads make them very stable.

I'm going to look at some 8/4 black walnut today. I feel these bases warrant something special on top. If anyone has suggestions on where to find something, please advise.

[ianab]

Gut feeling is that if you are putting a 2" thick slab of wood on top of those pedestals it's not going to need any other support. Unless you find the need for some cross supports, if the top is wide and is only going to be supported by the screws near the center?

Assume it's something you bring in as separate pieces and just drive some screws up into the base to hold it together?

We are in an earthquake risk area, so I'd also drive some screws into the floor, just in case. You wouldn't want that construction to topple on on you

[Bill Holt]

I agree, you will need support for the width only if the slab is close to two inches.  Are you using the large base and pedestal? If not, what will you use for the base of each pedestal?  BTW the refinished pedestals look great!!!!!!!!!!!

[pinky]

Yes, using the large bases, just have them apart while painting the letters.

[Wipedout]

Did I miss how wide the top will be?

[pinky]

Haven't bought the wood but thinking 36 to 44"