If it is wood framed and you hang it veritical it will show every wave in the wall at some point if not right away so horizontal works best. If its metal framed you can do it either way. If you are going DIY then hang it yourself and have a pro come in and finish it, wont cost that much and its better to get it right the first time, its a nightmare to try to repair once its not ideal.

 

ooops.

 

I'm no carpenter but a jack of all trades and master of none :blink:. But to my knowledge you always hang dry wall horizontaly so your vertical seams end up staggerd, otherwise if your floor to ceiling height is under 8' then you should go vertical. Just my 2 cents hope that helps.

 

It would be best to hang the drywall vertical.You only have to finish factory edges that way.If you hang it horizontal you have to to finish butt joints.To explain,the side of a sheet of drywall is rolled to less than the thickness of the rest of the sheet to create a slight recess when put together.When you put on the drywall tape it will be below the surface of the rest of the drywall allowing it to be finished flat.To finish a butt joint or where the end of the sheets join together the tape will be on the surface creating a bump when finished.

I would suggest the screen type tape that is sticky on one side.Make sure it it centered and pressed flat with a 4" knife.Use a drywall knife wider than the joint to finish, 8" works well.Use the 8" knife to put the drywall compound in the joint and use enough pressure to scrape flat,you are filling the recess not trying to build up the surface.Don't try to be perfect with the first coat because it is going to shrink,2 more coats and a light sanding will get you close to flat.Use a light off to the side and you will be able to see every imperfection.Paint your wall with flat white paint(because its sandable) give the wall a light sanding and then check it with the light.If you have any spots that need to be fixed,sand the bumps or fill the holes and touch up with paint and sand again.Useing the light you should be able to make the wall very flat with a little time and practice.If you have to fix drywall remember its easier to fill a dent than to smooth a bump,so make the bump a dent and you won't have any problems.
Hope this helps you out and good luck with your room.

 

I started to hang drywall in my small hallway in the basement going vertical. It worked out really well other than asking the wife to help hold the first piece of drywall on the ceiling while I screwed it in. Guess I will have to wait for reinforcements before any more drywall gets hung.

 

I have never seen drywall hung vertically and I used to work for a professional drywall company when in college.

Take the advise and at least hire a pro to mud and tape. Its a nightmare for the uninitiated and unless your really careful, you won't see your mistakes until your room is all painted and you turn your projector on for the first time.