To a degree, I would expect any property owner that has gutter systems on their home or business to believe the question as to whether or not their gutter system has seams to be a bit rhetorical.
After all, assuming someone is at least a little bit cognizant of gutter systems, they sure could quickly think/reply that, “Of course my gutter system has seams silly!”
In theory, they would be correct.
The definition of a seam (according to the Google Dictionary) in the case of gutter systems would be, “A line where two pieces of wood, wallpaper, or another material (components of a gutter system) touch each other.”
Technically, any place where a gutter system has any type of cut and is joined together would constitute a seam.
Examples of this with regard to a gutter system, could be their endcaps and inside & outside corners (or “miters”, if a particular run of a gutter system might have them).
I usually consider these places a “given”.
When I ask the question of whether a gutter system has seams or not, I am most often referring to longer stretches of gutter that have had multiple straight runs of gutter spliced together to make the entire run, vs. having a long, seamless run.
As with many facets of construction, the less number of seams you are able to have when constructing something, the better.
In the case of gutters, every single seam that exists, presents an opportunity for a leak at some point in the future.
Seams that exist on endcaps and miters are unavoidable.
Optimally, seams that are part of longer gutter runs that have been spliced together, should be eliminated, if possible, the next time the gutter system has passed through the course of its useful life, and is ready to be changed out to a new one.
In the meantime, I believe it is important to periodically check all of the seams of your gutter system to make sure they are not leaking.
One of the biggest sources of rotted wood and peeling paint we find on people’s homes, are areas behind seams on gutters that have sprung a leak over a period of time.
Although a relatively easy thing to keep intact, if you do not even realize that your gutter system has seams, it is obviously going to be a bit challenging to stay on top of.