I know so many 2x4s are overkill on my run, but a family friend built it (I paid him well) and he was sooo nervous about getting a call from me in a month or so and telling him something got into the run and got my ducks, lol. He didn't want to be responsible! So, better safe than sorry. notice my daughter has on a cast on, she fractured a growth plate in her ankle . The kid will not stay off her leg!! driving me crazy. I should just record myself yelling "SIT DOWN!"