It is partially used but i replaced the transom from the outside and the transom wasnt rotted all the way up. therefore i used a section of the 4' x8' sheet. it ma be tight but depending on how you are replacing it it should be enough. i would definately recommend you seeing some pictures if you are seriously interested. if you send me an email with your addres ill get you some pictures.
chrisvazquez1@gmail.com