Black shimmering lines between func_detail brushes

[Psyrius]

What kind of sorcery is this? 

https://gyazo.com/edc66cd6bacac364aae7f861eebbd4e5

From some angles, it looks ok...

https://gyazo.com/83e17602ddb870c82ecd65af0bd3bcbd

This is how the brushes are put together:

https://gyazo.com/7af9a7f76c82ce4106fb2556d6575ee8

I went ahead and placed the brushes abit differently:

https://gyazo.com/72fcbdc5b998e0170ac55bf2679f7fa3

Which fixed the problem, but now there's a black, shimmering line here instead:

https://gyazo.com/148b1cebd738dd5eac1d5705ff8480c9

 

[Logic]

I'm not an expert, but I have been experiencing the same thing sometimes.

If you're sure that there isn't an actual space there then deleting the block and recreating it should help. Sometimes it's another block nearby that causes the issue. Look at at other blocks nearby and find edges that alignes with the glitch  

[Psyrius]

I don't really know how I fixed it, but I placed them all in a different way like I did in the fourth picture, applied nodraw to everything and retextured. Now it works fine

[Pawl]

You could also make the window func_brush and 'Disable shadows'