So i am planning on making a cake for my son's 12th birthday. I dont' really have the money o go get a large sheet pan so I was thinking about making 2 13 x 9 cakes and butting them together side by side. Not so that it turns out long and skinny. First question is would it be OK to tort and fill them, second question is do I need to connect them together with icing. I don't want there to be a giant crack down the middle of the cake. Also I will be making a soccer ball cake to put on top, is there anything special that I need to do to put it on top or can I just put it there and ice everything. Thanks everyone.

I've butted two 9x13's together and it's fine. Just make sure your board is very sturdy, or else it will crack down the middle when you go to move it. Torting is up to you. Personally I do not torte sheet cakes, to much of a pain.

So I don't have a ton of experience here, I've only done this once myself but here's what worked for me! I trimmed the two edges that were going to be meeting slightly so they'd be straight and flush and not slightly tapered like the pan's natural shape and used NO frosting and pushed them side-by-side. Figured that way there'd be no risk of the frosting in the joint pushing up with any cake movement and creating a "bubble". Frosted the cake smooth and it worked like a charm (for my purposes, anyway!)

I always support the cakes that are above the bottom cake. You can do it simply with plastic straws and put the soccer ball on a cardboard round and all should be good.

I agree with above too, I don't torte a sheet cake, I make layers. The hassle, aggravation, breaking and cursing that comes along with torting a sheet cake vs making another layer? No contest for me!!

I made a number 3 last year from sheet cakes which happened to also be 3 layers. If you are using more of a cardboard weight board, add another strip of cardboard in the center (if you picture your board horizontally, add the extra cardboard vertically in the middle ). For my number 3 cake I put the whole board on a carving board I have that has metal handles and used that to transport my cake 45 miles or so. If you are having an at home party, you can still use your carving board for support! I iced between the joints but not a thick layer. I agree on putting the soccer ball on a cardboard round, which will also make it easier for you to cut later. Good Luck. Theresa

As has been mentioned, the most important thing here is to make sure you have a *very* sturdy board. Glue 2 or even 3 cake boards together if need be
I didn't read all the replies so don't know if anyone answered this already. Yes, 9x13 sheet cakes can be split and filled if you want. Another method of filling them is to use the 'injection' method. Take a small round (2,3, or 4) on a piping bag; fill with a smooth filling (icing, bavarian cream or other pudding type) and poke the tip into the cake and give it a rather good, healthy squeeze; take the tip out and move over about 2" and repeat. Do this all over the cake. I have made many, many lg sheet cakes by putting together as many as 5 cakes to form one very large one - here's one http://cakecentral.com/gallery/1271950/in-the-jungle

Yes, you can but one 9x13 against another 9x13 to make a larger sheet cake.
About 1/2 of my cakes are sheet cakes 1/2 sheet to full sheet size that I have butted two cakes together because many of my customers want 2 different flavors in one large cake. I always torte them too.
Like the others have said, a strong board underneath is a must.
I would also support the soccer ball cake with straws just to be on the safe side.

I was wondering the same because I don't have a half sheet pan. If you sandwich them together and put buttercream and cover with fondant I'm afraid it will have a crease in the middle. What can i do to prevent that?

I do torte and fill my 1 layer sheet cake. Never had a problem. Never had one to break. If they want to pay for a 2 layer sheet cake, then i will make a 2 layer one. I also would torte them also. I like thin layers and filling between them. We all do things different and then alike. That is good. I use the same size cake board as the cake to move the top, etc. and then place it back after the filling.

......sandwich them together and put buttercream and cover with fondant I'm afraid it will have a crease in the middle. What can i do to prevent that?........

You prevent a crease in the middle by making sure both cakes are the same level. Best to put them together on the board, then level them so they are exactly the same.
Putting some icing between the two where they join will help also.