Does having to replace a roof qualify as an emergency expense when withdrawing money from retirement

It could, but be aware that only $1000 of the emergency distribution is excluded from the 10% early distribution penalty.  The 10% early distribution penalty will be assessed on the remaining distribution.  The penalty is entered on your federal tax return as a tax liability.

As indicated by DoninGA the amount of funds for emergency maintenance on your home is limited. 

• Distributions using the financial emergency exception are limited to one per calendar year and a maximum amount of $1,000
  • For more information and future possibilities you can view the links below:
    • What are the exceptions to the penalty for early withdrawal from my 401(k)?
    • Can I make a hardship withdrawal from my 401(k)?

Be sure to enter the correct codes in box 7, when entering your 1099-R into TurboTax. TurboTax will ask the appropriate questions for your return and the retirement distribution.