Roofing Shingle Layers

[Ray J.]

We just purchased a very small (825 sq ft) SFR (Fix-N-Rent) in a C neighborhood with 5 layers of shingles on the roof and it has obviously been this way for at least a few years. I know you should only have up to 2 layers, some people even say only 1. Before purchasing, we got a home inspection and of course this was also pointed out by the inspector. But he also said, after walking the roof and inspecting the attic, that the roof was in great shape, other than that, and everything else appeared solid with no evidence of leaks. And it was raining during the inspection.

This is an older home.  We also got an inspection and quote from a roofer to correct this.   The numbers still worked out the way we like, so we purchased it.  Other than the roof, it only required a light rehab internally, which will be finished in about two days.  There's no question we plan to replace this roof and we have the funds, but I'm wondering if it's something we should rush and do immediately given that the roof seems to be in great shape and has been the way it is for a while.  This option would give me the opportunity to invest that money elsewhere and collect more rent, plus the new rent from this house, before replacing the roof.  The roof is small enough to complete in 1 day ,2  tops (presumably mostly while the tenant is at work), so it shouldn't disturb the tenant too much.  We'd inform them prior to lease agreement that this will happen in the summer.   Or do we need to get this done ASAP for some reason unknown to me?  

I've only been investing for about 3 years, and this is my first roof "problem", so I appreciate any insight from someone more experienced than I.