Requesting extra funds from lender for possible rehab mishaps

[Brandon Clark]

Hey BP, quick question about financing loan amount. 

My loan is 80% LTV of the purchase plus rehab net. I wanted to know if it was normal to increase the amount requested for the rehab to pay for any unexpected expenses. An example would be; if the estimated rehab is 30k, I would request 36k for any extra rehab issues that pops up. If I don't use it I couldn't potentially use it don holding fees or maybe closing cost. I'm not sure if this is a strategy that many investors use or is it frowned upon. I hope my question makes sense.

Thanks in advance 

-Brandon