I hope that all those records were horrible titles that are widely available in unwanted numbers in bins, or records so badly scratched (or otherwise damaged) as to be unplayable. With 350 of them all looking so nice in the picture, I doubt that was the case.
The idea is a little innovative, but generally not very practical. In a permanently-shaded location in a cooler climate, it might last a while... but as the labels fade, the records (probably, eventually) warp, and as they gradually become more brittle and chip and crack in places, it will become more of an eyesore than a nice roof. But anything and everything ages, so perhaps that isn't the best argument against it.
If that area ever gets even moderate snowfall, the records may not support the weight, which could even become dangerous, if they broke in numbers when someone was on the porch.
If, by accident (say, from a kid's ball hitting the top, or a carelessly-wielded broom handle from underneath, etc...), one or two records in the middle broke, unless you could slip replacement records in from underneath or something like that, you'd have a hard time replacing broken ones. You can't exactly walk across a roof of records to get to the middle of them! In that sense, tar paper, which is cheaper, more durable, more waterproof over larger areas, less affected by temperature change, etc... would be a better, if more conventional, choice. There are reasons why it is usually used in such applications. Similarly, the commonly-seen galvanized corrugated tin would be a more practical choice.
I think the key factor in whether I would approve or disapprove is WHAT records were used. Nice, playable ones that someone would want? Then I'd say :thumbsdn:, but if they were damaged and worthless discs, then --other than the practical drawbacks-- why not? [I won't go so far as to say it's good, because I'm not even sure that it's pretty, although in a way it is, and it does have an unusual character to it, something I usually approve of.]