DIY: Do it yourself (DIY) is the method of building, modifying, or repairing things without the direct aid of experts or professionals.

Time Consuming

 Since you are not a professional in repairing roofs, it would take a long time for you to understand the problem, buy the materials, and learn how to fix the part that has been damaged in the roof. Hence, it would be more time consuming to do it by yourself.

Risky 

 Since you do not know the techniques of how to fix the roof and how to use the complicated tools, you could end up injuring yourself while making the repairs. Just being on top of the roof can be dangerous if you are not able to maintain your balance.

Expensive

 Since you do not know how to fix the roof in an easy manner, chances are you would go out and buy the tools and materials needed for roof repairs and end up spending more money than contracting the repairs of the roof to a professional.

May not be perfect

 If you make the repairs to the roof by yourself, you may not achieve perfect results as you are not a professional and it is not your daily job. There could be leakages or any such things that can reoccur if the repairs are not made in the right manner.

No extra services

 You will not get extra services which you would have got from a professional roof repair company if you fix the roof by yourself and you may miss out on interesting follow-ups and offers that the companies provide after repairing the roof which could have been of great value.