If you receive a check from insurance company to replace roof can you do the repairs yourself?

It is a question of honesty..... If you told the insurance company you were going to do it yourself and their check is for materials and some of your time then this would be OK. However, if your claim quote was for a builder to make the repairs, then their check is for this work and you should tell the insurance company that you intend to do the work yourself or you will be defrauding them.

You must also remember that if you do the work yourself and the roof is damaged again they will probably refuse to pay (unless you are a qualified builder) on the basis that your initial repairs may have been inadequate.

The fact that you asked this question indicates that you are basically an honest person - stick with the honesty and don't try and make money out of an insurance claim - it is not what insurance is for.