# Problem with fibafuse or bad luck



## island slinger (Sep 1, 2018)

I'm in the middle of finishing a big project and as usual I tape the flats with fibafuse and corners with paper. There's a large room, about 42' x 18' with large doors at both ends. A few days ago we had a day and a half of solid rain at about 85 degrees. Following that with dry air at 65 degrees blowing through the room all day after a cold front.
I noticed early yesterday that a couple of the butts were cracked on the walls. By the end of the day almost all of the butt joints were either cracked or bubbled up. 
There's three bedrooms next to this room that were closed up and there was nothing wrong with the joints in them. Still fine this morning.
I've accepted that I have to repair ~40 butt joints but I'm afraid it will happen again. What do I do? I'm thinking of using paper this time. 
What do you think the cause of this was? Large room? Going from 100% humidity to windy, cold and dry over a couple days? Both? 
I've attached a couple pictures of the joints.


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## cazna (Mar 28, 2010)

Wow, Wouldnt it be a fixing and movement issue?
Bizzare thing to happen did you use lightweight mud to tape?


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## hendrix417 (Aug 9, 2018)

yes, what mud did you tape with? i hope it was bucket mud....


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## legendofrock (Feb 13, 2019)

The joint was still wet when you second coated and skimmed. You may have been dry but you weren't cured. Took me a while to get my head around it too but it killed me for the longest time. When moisture is that high it takes a lot longer to cure all of the way, sometimes up to 72 hours. USG has a chart you can download that shows temp and humidity and how long it will take to cure.


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## hendrix417 (Aug 9, 2018)

regardless, only fast setting mud should be used to tape. or am i wrong?


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## island slinger (Sep 1, 2018)

Sorry for the delay in responding.
I forgot to mention that I prefilled all of the joints with durabond. Trapped the next day with Pro Form all purpose. I probably had two days before second coating.
It can't be a framing problem because the walls are concrete and stripped at 16"oc. Ceiling maybe, but doesn't explain why the walls are having a problem too.


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## Superchief (Mar 9, 2016)

When you says walls are concrete is this above or below grade, and are they ICF or just a poured wall? When were they poured and are they still curing (technically, the answer is always yes but you know what I mean)? How were they backfilled (e.g.: good drainage) and waterproofed? Is there a functioning perimeter drain at the footing?

I know less about drywall then I do about buildings and concrete so I'll defer to others on your issue, but there are a lot of ways concrete can give you a serious moisture problem including condensation on a cold surface, passing through the wall, and wicking up the wall from the footing if not properly detailed ... so the question I'd be asking myself would be is moisture the source of your problem? I think taped joint compound is water soluble and will crack if excess moisture is present ... and if it is present, it may well crack again ...?


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