Reader DIANA writes, ”skylights leaking in 40 year old barn. Is it possible to replace the sky lights with metal.”
Skylights in steel roofs are problematic, and not just due to them eventually leaking. You will certainly want to read this article: https://www.hansenpolebuildings.com/2016/01/one-more-reason-to-not-use-skylights-in-steel-roofs/.
Now, considering your entire roof is 40 years old – it would be possible to replace only skylight panels. This would be providing rib configuration of steel can be matched. Over 40 years many patterns have been discontinued.
You asked for my expert opinion and I therefore take upon myself to answer as if it was my very own building. This isn’t about trying to make money (although some readers may become Hansen Pole Buildings’ clients following reading of a few of my articles), it is about people getting a great value for their building dollar. I’d be first to admit to it, if I did not believe our buildings are an example of best value.
If someone actually does happen to have a better value component, let me know and we will try to incorporate it and, if possible, improve upon it.
I’d look to replacing entire roof surface. Paint systems, such as Kynar (https://www.hansenpolebuildings.com/2014/05/kynar/), are available in most U.S. areas. There are also ‘Lifetime’ warrantees available on many SMP (https://www.hansenpolebuildings.com/2014/05/smp/) painted products.
Your existing roofing was probably installed using nails, rather than screws. It was industry standard then (read more here: https://www.hansenpolebuildings.com/2011/12/ring-shank-nails/). Ideally a new roof panel screw layout will be such as with some adjustment all existing nail holes can be missed.
I’d recommend using powder coated Diaphragm screws to attach roofing to underlying purlin framing. You can read why here: https://www.hansenpolebuildings.com/2012/08/this-is-a-test-steel-strength/.