Is it required to close a runway if the paint has been removed for resealing the asphalt?
While some regulations or guidance material may call for some or most runways to be closed during maintenance or construction work, such as marking removal for asphalt reseal, this is certainly not always the case.
If markings are non-standard, faded, or removed, for any reason, the condition should be documented in a Notice to Airman (NOTAM) so that pilots and other interested parties will be aware of the condition and prepared for the non-standard situation.
An example of such a NOTAM includes this one from Randolph AFB (KRND), where some markings on runway 14L/32R are missing dues to removal and repaint during maintenance or construction work.
RWY 14L/32R SURFACE MARKINGS NON STD ; SOME MARKINGS MISSING DUE TO REMOVAL AND REPAINT.
Note that runway 14L/32R is not closed during this work. However, the parallel runway, 14R/32L, is closed:
RWY 14R/32L CLOSED
IT relies on being a Part 139 airport, mainly. the Marking Standard, AC 150/5340-1L states the guidelines and standards for marking are the only method of compliance with airport certified under Title 14 CFR Part 139. Part 139 is the certification and clasification of passenger airports. Markings are also required for any airport receiving Federal grant money through the AIP Program. Basically, if you are not a passenger airport with scheduled or non-scheduled service of aircraft with 30 or more passengers, or if your sealing project is not funded through a Federal AIP grant, you may leave temporary markings off as long as NOTAMS are issued to this effect to the pilots - that the runway is unmarked and they are on their own discretion whether to use or not. At least, this is my understanding. See the AC. I should also point out the "Operational Safety on Airports During Construction has the same compliance requirement - AC 150/5370-2L - applying to Part 139 and AIP grant program airports. This is why you may see non- standard markings or no markings (grass field) on private airports.
But there is a secondary consideration - State Funding Grants. You may need to check with the State Aviation Responsibility if they are paying in part for the work as if you need to meet the FAA requirement. Some states may be lenient due to cost. State grants are applied on a matching basis, and it may cost a local GA only 1/10 the cost when receiving a State grant for the work. Since even a simple seal and repaint project can cost $100K or much more, the decision to close a runway may rest with the State agency. You see, most GA's no matter how small are eligible at times for FAA AIP or State matching grants, and this drives what they do, and why most non-commercial GA's still meet the FAA AC's for marking and construction safety.
Any corrections gladly welcomed.
Yes, of course you have to close it since it falls under the runway closure reason of "Obliterated or faded markings on active operational areas." From this document. The "Obliterated markings" is what would cover the removal of the markings for any reason.
And with even simple common sense, why would a runway under construction be even open?