[Simulated (OP)]

We've gotten a lot of rain lately and we'd see the gutter in the corner of the garage keep overflowing without more then 1/4 and inch of rain. We went up there today to see what was going on and we found this.



At first I thought it was just the little pieces of shingle that had came down into the gutter during the storm, since we just reroofed two years ago, but after we pressure sprayed it all out of there I went down and felt it and surprisingly it was spongy and still in large chunks, the parts of the shingle woudln't be spongy and in large chunks. Dad said it reminds him of what "grows" in the sump pump. I wasn't gonna post this until he said that.

Here's some more pictures





Thanks Sim  []

[blakestyger]

Slime mould?

[LeeE]

Out-of focus pictures are useless - worse than useless actually, because they could be anything.

It's bacteriologically modified gunk.

[Simulated (OP)]

Yeah, it ain't in any of the other gutters either.

And sorry. Our camera is a piece of junk.

[Karen W.]

Ohio Gutter fungus!

[Karen W.]

Maybe your gutter foam has deteriorated and is crumbling and deteriorating! Some gutters have like a foam filter thingy inside them to filter out debris etc...

[paul.fr]

Are you sure that it's growing and not a collection of leaves and other plant material that is all clumped together?

[RD]

Possibly tar-paper...

Roofing felt, one common type of tar paper, is a fiberglass or polyester fleece impregnated with bituminous material (tar, asphaltic bitumen)

http://en.wikipedia.org/wiki/Tar_paper