Sub-contractor accountability contracts

[Robert Freeborn]

On a recent flip, I had an electrician set us back by 3 weeks with no shows, walk-offs and other delays.  I want to put together some contract that I have all my subs sign with some sort of contingency to cover events like this, maybe with a penalty against the final invoice per missed day or walk off. I'd also be interested in a general, "any expense or total expenses above 10% of invoice bid require direct approval. If you go over that without permission I will only be responsible for the 10% overage."  

Anyone have anything prebuilt like this you'd be willing to share?