On Tuesday, September 1, 2015 at 8:27:25 AM UTC-5, Stormin Mormon wrote:
I'm working with some church guys on a roof shingle
project. The compressor is in the garage, at the
power socket. There is air hose going to the air
nailer, which is in use on the roof.

A couple times, the hose was not long enough to
reach. The question was raised, should we get more
hose, or an extension cord and move the compressor?

There can be problems with air flow. There is also
voltage drop in extension cords. Which should we use?
--
.

On a serious note, have you looked into renting a small trailer mounted air compressor or one you can put in the bed of a pickup? You can pull it around to the side of the building you're working on and the air line or lines may not have to be pulled that far. You could ask the rental store for a break since it's for work being done on a church. Around here, vendors will often donate things for work being done on churches since most of them aren't multimillion dollar mega churches. I've donated time and material for repairs to "small" churches of different faiths that I don't share simply because the members are nice people. Perhaps someone will loan you a gasoline/diesel powered air compressor? ^_^

http://tinyurl.com/nvl7btn

[8~{} Uncle Compressor Monster