I have clauses in my lease saying I'm not responsible for injury or loss to person or tenant's property, and that tenant waives all claims.

To add insult to injury, you are saying how you want to hire him for other jobs.

I would like to at least work through the pain and get this done and worry about the consequences later, but I don't know enough about knee injuries to understand what kind of damage I could cause.

As we age, we have less tolerance for risk, loss, injury and having knives pulled on us.

Structure seems solid and there are no obvious irreversible repairs.Here are the details:1526 Sq Ft

We've both had employment with the same company for over 2  years, it's just between getting pregnant and having down time post injuries we've been living off of our savings and staying with family until the work is full time again. 

I was very fortunate, escaping with just minor injuries, a few stitches to my Achilles area of my ankle. 

(Of course there would still be the likelihood of injury from a falling piece of sky)

Is there a way to add something to the lease that they can agree that they use it at their own risk and can't hold me liable for any injuries?

(a) A tenant's judicial remedies under Section 92.056 shall include: (3) a judgment against the landlord for a civil penalty of one month's rent plus $500;(4) a judgment against the landlord for the amount of the tenant's actual damages; and(5) court costs and attorney's fees, excluding any attorney's fees for a cause of action for damages relating to a personal injury.