I think I messed up the taping

[Bodrey]

I'm renovating my house right now including installing new drywall. Just today, I started taping the living room, but now I'm seeing that some of the tape seems to be blistering/bubbling up along the seam. The one in the pic looks especially bad. I think I installed the drywall tape backwards. Is it true that the crease in paper drywall tape has to face inwards towards the wall? If that's the case, I may have to re-do at least some of my taping. Some of the tape doesn't look bad at all, but I still don't know if that will come back to bite me. For those runs, will I still be able to apply compound over the tape as is and not have any imperfections show through? Does the crease still have to face inwards for inside corners as well? TIA for your help.

[HankBriggs]

Is this a straight line or corners?

Otherwise, you didn't tape it backwards. That crease in paper tape is only relevant for folding it into an inside or outside corner — on a flat butt seam it just lies flat, so there's no "right way" to orient it. What you're looking at in the photo is a classic air pocket or thin spot in the bed coat, not an orientation issue.

That ridge almost always comes from one of a few things: not enough compound behind the tape in that spot, pressing too hard with the knife and squeegeeing out the mud that was supposed to hold it down, or embedding over mud that had already started to skin over before you got the tape smoothed in. Sometimes it's also just trapped air that didn't get worked out during embedding. Whatever the cause, that section needs to come out — cut it back to clean drywall, re-bed with fresh mud, and re-tape. Don't try to skim over it; a bubble like that will crack or show through your finish coats later.

For the rest of your seams that look fine, don't just assume they're good — run a taping knife firmly over the full length and feel for any give or crackle, or hold a work light low and to the side to rake light down the seam and check for shadows from ridges. If a run feels solid and flat with no hollow spots, you're fine to coat over it as-is and don't need to touch it.

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