My roofer informs he will replace, where necessary, the 3/8th sheathing with 1/2 inch. Says the new roof will not look any different, as the difference is so small. I had a bad winter with some leaks. Roof replacement is required. Want Dimentional Roof to replace 22 year roof. Is using 1/2 " to replace "some" damaged 3/8 inch a problem? Means I will have a mix. Difference of 1/8 inch seems so small. I have been with this roofer for over 40 years. I have confidence in his work, etc.