Trimming a roof ridge cap - GIF

[old kodger]

What's the point in trimming for the sake of 25mm. It was better left alone.

Sorry bony, you got that one wrong, he's not "trimming" for the sake of 25mm, he's profiling the capping to fit the roof tin shape,AND IF YOU DON'T,WIND WILL BLOW WATER UP UNDER IT.

[Frank S]

Sorry bony, you got that one wrong, he's not "trimming" for the sake of 25mm, he's profiling the capping to fit the roof tin shape,AND IF YOU DON'T,WIND WILL BLOW WATER UP UNDER IT.

Most metal roofers just install corragated rubber under a cap without the turned down lip as the one in the video, because it is so much faster and costs much less than the labor to trim a turned down lip. IMO the trimmed edge gives it a more professional look. You can also buy caps fully shaped with the corrugations already there. Those are the most expensive and have a true blended finished appearance, also do the best job of sealing out wind and rain or insects