# Inside Corner / FibaFuse Help



## kiegscustoms (12 mo ago)

Looking for any advice as to what may be going on here. I'm building a new construction house through every phase of finishes. I've done drywall, amongst other things, professionally for the last 20 years.

I've used Fibafuse and Fibafuse max plenty without any issues. I use Fibafuse on flats and butt joints and Fibafuse Max in corners. I also like to use USG Lite Taping Compound for bed coat or USG Plus 3. 

I hung and taped 5800 square foot ( surface, not floor sft) of drywall there last August through middle of September and I was unable to get the Fibafuse Max for or either of my preferred USG compounds due to shortages or unavailability. I was able to get the Regular Fibafuse (from Lowes) which seemed thinner / weaker / had less fiberglass strands than I'm used to seeing. I also was forced to use Proform Red Top Multipourpose compound for all coats. All research and based on fibafuses website it is appropriate for use in inside corners. I purchased a Level 5 corner roller and 3" Level 5 Angle head to set and flush the corners, then finished with the Level 5 3.5" Angle head on their corner applicator box.

Everything looked great through primer and paint which was complete by the beginning of October. This job is in a northern cold climate and the house was kept tempered around 50 - 55 degrees indoor with outdoor temperatures ranging from 40 down to 20 degrees as finishing continued. 

I noticed some weirdness in one of the inside wall corners about mid November. It looked like the paint had bubbled up almost like air was pushing it out. 

The beginning of December the outdoor temperatures have dropped between 35 and 10 degrees. Heat Pumps were installed and the temp has been held at a steady 67 degrees and a relative humidity in the low 40's indoors. 2 Weeks ago the ERV air exchanger was hooked up and there is a scheduled air exchange every hour. 

Now almost every wall / ceiling inside corner has developed a crack. Some hairline and some quite severe. Also several vertical wall inside corners have developed the same strange paint bubbling situation.

I cut the bubbled paint away to see what was going on today, keeping the knife blade along side the paint blister and out of the inside of the corner. and there is no connection of the Fibafuse tape in the corner. As though it has completely failed. I will mention that any gap in EVERY corner was prefilled with EZ 45. 

I know this is a lot of info to process but after 20 years of taping and finishing I've never seen this to this extreme. Maybe a hairline crack very rarely, but not a catastrophic failure such as this. I mention temperatures humidity and air exchange as variables in overall climate of the drywall.

Below is an example of the vertical wall corner bubbling and the wall / seiling corners cracking.

Any input is much appreciated.


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## picks drywall (Apr 13, 2021)

i would never use fiber tapes in corners. nor with regular mud. 

slice the bad spots and tape with paper to fix. and hope the rest dont fallow suite. something probably moving.


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## austinwoh (12 mo ago)

This is a video on everything you need to know about installing drywall.. hope you find it as helpful as I did.

[Smoner]


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## 🤡 drywall 🤡 (Feb 12, 2021)

I would not have used fiba fuse or fiba fuse Max on inside corners and or inside angles, only paper tape, but none the less it looks like movement, or settling has taken place since the drywall was finished and painted. Not sure if weather did or didn't play a role in it also because I've seen paper taped joints and corners/angles crack like this before too, my thoughts is still that some settling/ movement of some kind has taken place, hope this helps or encourages your situation...


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## David Schwaiger (6 mo ago)

It does not look like the structure is stable for there to be that wide of a split. You might need to open up the areas where that is happening and prefill them with hot mud. Durabond would be best if you can find it, if not you can use the USG or Proform quick setting powders. They don't shrink! I personally would use a composite corner since they are more rigid. If the house is settling, you might have a fight on your hands. If there was an installation issue, you would only have small cracks, peeling, or the edge of the tape bubbling. The only issue I have ever had with Fibafuse in a corner is cutting through it with my knife on my first coat. I do prefill the wider gaps which helps prevent me from doing that. I don't care what anyone says, fiberglass is lot stronger than paper by a large margin.


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## Yunggranmassa (Oct 9, 2021)

Honestly dude, one question -- Two things

First of all: Did you prepack any & all gaps you could fit a hatchet blade between in all your corners with 20 before you taped?

Two: 
You're shooting yourself down running mesh in bucket mud. Mesh must be run in a full bedcoat of hot mud if it's used to tape with.. 

And, Three: Paper is the proper. Screen tape sucks. It's for painters, people in a hurry, & DIY homeowner patchwork. 
As a finisher, I view it as a decadence to the drywall trade & something that needs to banned by the ICC. It does okay in the modular homes, but that stuff will not withstand the testaments of a stick frame home as it breathes & settles throughout the first 6-12 seasons following construction. Fibafuse is just a more refined & better polished turd to the rest of the mesh.
I've given the screen stuff it's chance.
I use to leave off all my closets in a house until I step finished everything else; because I thought it would be quicker & easier to screen tape all the closets, slop-hound em all in 20, then scrape the green and call them good..... I decided after a month or two I wasn't doing myself any favors and I thought it made my work look shoddy. So I went back to doing the closets traditionally, same as the room, before moving on to the next room. I still run some closet flats in Fibramesh & 20 time to time; however, everything else I run in paper because I wouldn't trust that stuff on ceilings, butts above door ways, or windows..... and I definitely wouldn't run my angles in it. Paper is the tried and truth👍


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## David Schwaiger (6 mo ago)

Yunggranmassa said:


> Honestly dude, one question -- Two things
> 
> First of all: Did you prepack any & all gaps you could fit a hatchet blade between in all your corners with 20 before you taped?
> 
> ...


Fibafuse is not mesh tape, it is a woven fiberglass and is a direct replacement to paper tape. It is all I use now. I never have bubbles and my bed mud dries quicker. And yes, I always prefill with hot mud so that I do not have a ditch to fill when I start coating my joints. It is the professional way to do things!


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## Yunggranmassa (Oct 9, 2021)

It's an $11 roll of screen tape that potentially serves as the only admissible alternative to paper tape if it is strictly run using setting compound, not bucket mud. By no means is it the Gospel of John. Pookie roller, corner roller, glazier; roll-papertape-swipe-roll-stripe, & that's the professional way to run an angle with no bazooka boo boo.



David Schwaiger said:


> Fibafuse is not mesh tape, it is a woven fiberglass and is a direct replacement to paper tape. It is all I use now. I never have bubbles and my bed mud dries quicker. And yes, I always prefill with hot mud so that I do not have a ditch to fill when I start coating my joints. It is the professional way to do things!


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