I have an order for "sheet cake" for 500. I don't typically do sheets (nothing wrong with it just not usually what folks order) but what I'm wanting to do is 1 large cake to make a big impression. So, I'm thinking put 4- 16" cakes together (2 layers) or 4- 13x18 (also 2 layers) and have 1 additional to make up the servings.
Has anyone done something like this before? Any tips on decorating a cake that size?
TIA for your input

Please discuss this with the customer.

They may want standard 12x18 sheetcakes to be served as efficiently as possible. In which case one large cake would really defeat their purpose.

Such sheetcakes would normally have 2 layers and a simple piped border (shells, where I come from).

Thanks! They did tell me that one giant cake is fine. It is for a major anniversary so I think they are looking for something unique and decorative, especially since I charge more than the grocery stores.

I would think about one larger cake (maybe 100 serving) to be a centerpiece and then a kitchen cake to make up the servings.

For a giant cake, you need to use a masonite or plywood base well covered with foodsafe material.

The consideration would then be how big are the doors to the venue? because that will be a limiting factor.

As to the cake itself, you can layer 4 cakes deep as long as there is cardboard in the middle. A 32" square made up of 16" squares, 8' deep, would be fine IF you can get it into the door.

Decorating--go to town using larger tubes and everything like printed images to scale. Maybe a central round second tier with the logo and a message on the base tier?

I agree with BakingIrene. Even IF they told you that "one giant cake" would be fine, you need to consider the HUGE logistics involved.

I worked at a local VA Hospital for years. Every year they would celebrate the anniversary of the Marine Corps with a "giant" sheet cake in the Multipurpose Room at the Hospital. I was not into the hobby of cake decorating at that time, but now know that the cake was approximately 500+ servings. It was about 5 feet x 6 feet. The Marines had to transport, carry, and place that cake. The Hospital had double wide auditorium sized-doors and giant tables. The cake must have weighed a ton! It was a single, 2" high layer beautifully decorated with the Marine Corps logo.

Even though you want to "Wow!" your customers, I would suggest you consider full sheet cakes or half-sheet cakes. It will still be impressive, but FAR more manageable.

A 5 feet by 6 feet cake is not the way to go unless you have a flat bed truck and an army to carry it...

But a deep 2 tier cake will make it into most minivans/hatchbacks and need 4 people to carry it. Put 1" feet on the bottom of the cake board so that people can get their hands underneath.

I must be missing something so thank you for your help.

My thought was that a 2 layer 13x18 cake will feed 100. If I put four of those together (so 400 servings) the cake would be 26x36 (and about 4" tall) which would require a piece of plywood 30x40. I measured my car and my door, I can go over and measure their door. I am making calls to secure help for carrying this thing, cuz I know lil ole me can't do it alone.

Are my numbers off? I am kind of over tired these days so maybe I have it all backwards. They don't want the cake to have tiers so I'm stuck with something flat. I just cannot bring in something that they could have gotten from anywhere (appearance wise anyway, I know the flavor will be bangin'! )