What to do about drywall seams cracking ...AGAIN!

[Robert Macy]

how to repaire [and prevent future cracking] WITHOUT adding a big LUMP
to the seam?

The wall run is around 60 feet and 10 feet tall. the junction right in
the middle is wanting to crack. Trying to keep from forming lumps on
the wall, I cut down, used paper tape with a layer of mud under and a
layer on top. [Many may remember the problems I had posted earlier. I
tried to wet the tape first thinking of wall paper and how that
shrinks to fit, but wetting CAUSED the paper to 'slide' as it dried
and thus a crack, so in response I took all that out and did it again
with dry paper tape, which did work better. Only had the tiniest of
hairline crack form all summer long only about four feet of run on the
wall only.]

Well this winter as we isolated that section of the house - meaning
cooler temperatures and probably contracting drywall sheets, the
crack(s) opened up with a vengence! I mean over 3 mil separation!, but
worse the crack is the full floor to ceiling AND even now goes up
along a ceiling section which I never had trouble with before. I
suspect in the heat of the summer the crack will close back up, too.

Yes, I know houses change shape with time, but this seems too much to
be caused by 'settling'. My conjecture is is that this is more caused
by 'flexing'. Oh yeah, the seams are ON a stud(s), so there should be
no reason for movement there.

So, my question is
How do you repair/prevent cracking at drywall seams WITHOUT creating a
huge lump on the surface? I already have built up 1/8 inch thick to ++
on these stupid seams.

[Frank]

I've used fiber glass tape, looks like screen, on cracks around door
frames that kept coming back. OK today.

[tra...@optonline.net]

I don't think the thickness is going to do much. There
isn't much tensile strength to drywall compound. If the
drywall moves, it's going to crack. And it sounds like the
movement is related to temperature and possibly humidity
changes. You say the room is "isolated". What does
that mean and how cold does it get? For small cracks
that are persistent in 90deg corners or similar, I've used
a flexible caulk type filler. don't know how practical that
would be for a long, mid-wall joint though.
But

[Norminn]

clipped

> So, my question is
> How do you repair/prevent cracking at drywall seams WITHOUT creating a
> huge lump on the surface? I already have built up 1/8 inch thick to ++
> on these stupid seams.
>

My simple solution to fine cracks, when I paint, is to push some
paintable, flexible caulk into the crack. Usually a problem at corners.

[Tim Watts]

+1

This is the only "proper" way to do drywall joints. The tape spreads the
strain over enough area that the plaster/filler on top can tolerate it
without cracking.

The only time I've seen paper tape in use was to joint drywall that was
painted direct without even as much as filling the joints - eg a crap bodge
(cheap 1980's apartment builders in south London). Noone who is sane and/or
not cheap would do it like that now.
--
Tim Watts Personal Blog: http://www.dionic.net/tim/

"A fanatic is one who can't change his mind and won't change the subject."

[hr(bob) hofmann@att.net]

You mean the wall is 60 feet long and 10 feet high, and there is a
vertical crack somewhere toward the middle of the 60 feet??? That
long a solid wall, without any expansion provisions is asking for
cracking if it experiences a full range of temperatures and humidity.
Is this an interior wall, surrounded by interior spaces on all four
sides, front and back and two ends, or is one side or one end an
exterior facing wall? What do you mean by isolated, isolated from
what???

A better description of the entire situation would allow folks to give
you a more meaningful and workable solution.

[DD_BobK]

On Jan 6, 6:44 am, "trad...@optonline.net" <trad...@optonline.net>
wrote:

Drywall "moves" more than steel but less than aluminum based on
temperature changes.

It it also wants to move quite a bit based on relative humidity....

Thermal Coefficient of Expansion: Unrestrained: 40-100 °F (4-38 °C):
9.0 x 10–6 in./in./°F

Hygrometric Coefficient of Expansion: Unrestrained: 5-90% r.h.
7.2 x 10–6 in./in./% r.h.

So keeping the the drywall within a narrow range of both temp & RH
will minimize the tendency for the crack to open & close.

As T4 mentions, thinkness of the "patch"/ coverage wont help much.

With finishes... if brittle, they will crack with movement. So there
needs to be minimal movement OR the materials need to accomodate
movement.

Flexible caulk is an option that I use at corner joints, I've also
used it with success on narrow (less than 1/16") field cracks in
plaster.

You might consider cutting the corner tape & using caulk in the
corners.
A 60' wall is quite long and suffers a huge amount of dimensional
change with temp or RH... if all the movement is forced to be
accomodated at single line....you'll get a wide crack.

You mention 3 mil...did oyu mean 3mm or .003"?

.003 " can easily be fixed with flex caulk
3mm (.125") is huge

cheers
Bob

[recycl...@gmail.com]

I don’t know if this relates to your problem but I’ve been inside thousands of houses and all the ones I’ve seen that were over a slope or hill have constant movement going on all the time; some very little and others a lot but all were sliding.

[George]

On 1/6/2013 12:08 PM, Tim Watts wrote:

>>
>> I've used fiber glass tape, looks like screen, on cracks around door
>> frames that kept coming back. OK today.
>
> +1
>
> This is the only "proper" way to do drywall joints. The tape spreads the
> strain over enough area that the plaster/filler on top can tolerate it
> without cracking.

Bedded paper tape is the classic and standard way of finishing drywall
seams. The tape does the job you described.

http://www.thisoldhouse.com/toh/how-to/overview/0,,410343,00.html

[tra...@optonline.net]

> "A fanatic is one who can't change his mind and won't change the subject."- Hide quoted text -
>
> - Show quoted text -

Paper tape is widely used in the USA for drywall in both
new construction and repairs. Here in the NYC area
it is used almost exclusively in new construction. I
can't recall seeing the fiberglass tape stuff used by
pros doing construction. So, it seems to work very
well overall.

I've used both tape and the fiberglass tape. I think the
tape is easier to use and agree i may give some additional
benefit from cracking. It's worth a try. But it's kind of hard to
imagine that the tape is going to make a thin layer of
mud strong enough to keep two sheets of drywall that
are moving from cracking it. To me it seems like
expecting a very thin layer of concrete to have significant
tensile strength and keep two sections of concrete
from seperating because you add some reinforcing
mesh to it.

[DanG]

It sure seems like a lot of your posts indicate pretty marginal
understanding of construction.

No one would expect a 60' wall to not have any relief.

Here is a link to the USG Gypsum Construction Hand Book - pretty much a
bible for the drywall, plaster, and acoustic trades.
http://www.usg.com/resource-center/gypsum-construction-handbook.html#

Your current question is covered in Chapter 15 -Building Sciences. The
bottom line is that drywall should never exceed 30' without some type of
relief. Your best solution would be to install one or more expansion
joints in the wall. I prefer using Trim Tex parts, here is a link
showing you how they should be installed:
http://www.trim-tex.com/installation-sheets.html
Go down to the one entitled Hide away expansion bead

This will be a nasty remodel to get the extra stud installed in the
wall, but will be the best long term solution. I suspect that you have
a wall or something on the opposite side of the crack that is pushing or
pulling the wall at this point. and may even involve interior and
exterior conditions. If it is fracturing the tape joint at the ceiling
and mid wall, there is plenty of movement going on.

One stop gap approach that may last longer than what you've been doing
would be to remove all tape and mudding and replace with thermal setting
type compound and mesh tape.

Hope this helps you some.


--


___________________________________

Keep the whole world singing . . .
Dan G
remove the seven

[DanG]

Paper tape is the normal and usual material to use. The nylon mesh tape
can be used on tapered joints, but no tapers I know would use it on butt
joints or corners and so, most just use all paper usually installed with
a "banjo".

[dadiOH]

That is *WAYYYY* too thick! On butt joints at least.

Step #1 is to make sure the joints are securely fastened. If they aren't,
the joints will crack. One way to tell is to put your finger lightly on the
joint and have someone else thump the wall lightly with their fist a foot or
so away. Can you feel movement with your finger? (Note: you can't do your
own thumping).

Step #2 is to bed paper tape. Use only enough mud and width to bed and
slightly cover the tape.

Step #3 - after #2 is dry - is to sand as needed and apply more mud using a
wider knife. You aren't trying to cover the tape with this, you are filling
the gap along the edges of the tape created by the taped area being thicker.

Step #4 is to repeat #3 but with a still wider knife. By the time you work
up to a 10" knife the tape hump will be pretty much invisible even if it was
on butts, not tapered edges.

You mentioned that the cracks were over 3 mils. A human hair is about 3
mils so your cracks don't sound like a disaster. If the sheets are well
fastened, rubbing some acrylic caulk into them before painting as Norminn
suggested (she's a sharp cookie :) will fix them nicely.

--

dadiOH
____________________________

Winters getting colder? Tired of the rat race?
Taxes out of hand? Maybe just ready for a change?
Check it out... http://www.floridaloghouse.net

[cl...@snyder.on.ca]

On Sun, 06 Jan 2013 17:08:03 +0000, Tim Watts <tw+u...@dionic.net>
wrote:

Here in north america paper tape is the norm - the drywall is paper
faced with a tapered edge - the joint is mudded, the paper tape
embedded, and the surface leveled with mud.

Perhaps using a "curing" compound instead of a "drying" compound would
make a difference??.(Also called "Hot mud" or "quick set" or "setting
type") - has a number as part of the name - like "sheetrock 45" or
"durabond 90" It is higher strength.. The normal stuff is awfull to
sand - but there are now easy-sand versions. I would not use the
setting type for fine finishing.

[tra...@optonline.net]

> bible for the drywall, plaster, and acoustic trades.http://www.usg.com/resource-center/gypsum-construction-handbook.html#

>
> Your current question is covered in Chapter 15 -Building Sciences.  The
> bottom line is that drywall should never exceed 30' without some type of
> relief.  Your best solution would be to install one or more expansion
> joints in the wall.  I prefer using Trim Tex parts, here is a link
> showing you how they should be installed:http://www.trim-tex.com/installation-sheets.html
> Go down to the one entitled Hide away expansion bead
>
> This will be a nasty remodel to get the extra stud installed in the
> wall, but will be the best long term solution.  I suspect that you have
> a wall or something on the opposite side of the crack that is pushing or
> pulling the wall at this point. and may even involve interior and
> exterior conditions.  If it is fracturing the tape joint at the ceiling
> and mid wall, there is plenty of movement going on.
>
> One stop gap approach that may last longer than what you've been doing
> would be to remove all tape and mudding and replace with thermal setting
> type compound and mesh tape.
>
> Hope this helps you some.
>
> --
>
> ___________________________________
>
> Keep the whole world singing . . .
> Dan G

> remove the seven- Hide quoted text -

>
> - Show quoted text -

I looked at the link and installation for that product:

http://www.trim-tex.com/installation/Hide%20Away%20Expansion%20Bead%20Installation%20Sheet.pdf

I get the idea that it's a flexible strip that goes between
two sheets of drywall. But they don't say anything about
how it's finished? It would appear from the pic it gets
covered with mud? But, if so, what good does it do?
If the two sheets move relative to each other the mud
at the joint will still crack? Or do you not cover the
middle with mud? I think that would look a bit odd in
the wall, no?

[weather_...@weather.com]

This indicates that there will likely be a massive Earth Quake in your
area very soon. Once the house is destroyed by the quake, the wall
cracks will not be noticable. Your best bet is to ignore the cracks
while preparing for massive destruction and possibly your death. Now is
the time to buy homeowners insurance, life insurance, and prepare your
Last Will and Testament, and make funeral arrangements.

[Tim Watts]

It's not in the UK -

http://www.screwfix.com/p/no-nonsense-plasterboard-joint-tape-scrim-48mm-
x-90m/68520

I would take that as superior to paper tape anyday - not seen paper used for
over 20 years now...

[Harry K]

Agree about the butt joint. I tried it once and could discover no way
at all to put a thin layer on
top of it. When you "wipe" the wet joint compount the knife rides the
highs and lows of he tape and that tecture shows through.

As for the OPs problem. It appears that the framing is movign and
until that is cured nothing will
keep the crack from coming back.

Harry K

[gpsman]

On Jan 6, 9:37 am, Robert Macy <robert.a.m...@gmail.com> wrote:
>

> So, my question is
> How do you repair/prevent cracking at drywall seams WITHOUT creating a
> huge lump on the surface? I already have built up 1/8 inch thick to ++
> on these stupid seams.

More mud = more cracking. Tape/mud won't keep a wall from moving.

If the wall is moving, pull that sheet off and tie the studs together,
which if the studs are wood should have fire blocks installed between
them already.

The bed coat for the tape only needs enough mud to paste the tape
solidly to the wall; all excess should be removed, the tape should be
visible through the mud.

The 2nd (and 3rd) coats should not extend beyond the taper in any
direction.

You apply the 2nd coat and knife it level with the taper. The 3rd
coat, if necessary, is knifed identically.

Self-sticking fiber tape is often easier for the novice to apply, and
perfectly acceptable, the bed coat just goes over instead of under.
-----

- gpsman

[Stumpy]

<cl...@snyder.on.ca> wrote in message
news:0gjje8lvl8kvaa1ma...@4ax.com...

I agree about the mud. Everyone appears to dwell on the tape. Durabond for
the first coat should solve the problem.

[Robert Macy]

> bible for the drywall, plaster, and acoustic trades.http://www.usg.com/resource-center/gypsum-construction-handbook.html#

>
> Your current question is covered in Chapter 15 -Building Sciences.  The
> bottom line is that drywall should never exceed 30' without some type of
> relief.  Your best solution would be to install one or more expansion
> joints in the wall.  I prefer using Trim Tex parts, here is a link
> showing you how they should be installed:http://www.trim-tex.com/installation-sheets.html
> Go down to the one entitled Hide away expansion bead
>
> This will be a nasty remodel to get the extra stud installed in the
> wall, but will be the best long term solution.  I suspect that you have
> a wall or something on the opposite side of the crack that is pushing or
> pulling the wall at this point. and may even involve interior and
> exterior conditions.  If it is fracturing the tape joint at the ceiling
> and mid wall, there is plenty of movement going on.
>
> One stop gap approach that may last longer than what you've been doing
> would be to remove all tape and mudding and replace with thermal setting
> type compound and mesh tape.
>
> Hope this helps you some.
>
> --
>
> ___________________________________
>
> Keep the whole world singing . . .
> Dan G
> remove the seven

THANK YOU!!!

Wealth of information there. Took a few days to get downloaded, [dial
up] but worthwhile.

The expansion joint from Trim-Tex is very interesting. I actually
have the 'extra' stud inside the wall, so using it should be easy.

Any ideas on how to download Chapter 1? kept getting an error on that
one.

[tra...@optonline.net]

> one.- Hide quoted text -

>
> - Show quoted text -

Any ideas on how you finish that product? It's totally unclear from
the datasheet. What are you looking at on the wall

[George]

I just tried and it took a few seconds to get other chapters but chapter
one gives this error:

Not Found

The requested URL /documents/construction-handbook/chapter1.pdf was not
found on this server.

You may want to send an email to them report the broken link.

[Vic Smith]

On Tue, 8 Jan 2013 10:01:38 -0800 (PST), "tra...@optonline.net"
<tra...@optonline.net> wrote:


>
>Any ideas on how you finish that product? It's totally unclear from
>the datasheet. What are you looking at on the wall

Mud to the protected gap, pull protective strip, then sand.
You can paint inside the gap, or not..
www.trim-tex.com/installation/093V%20Installation%20Sheet.pdf

You're looking at an open V gap in the wall/ceiling, painted or not.
Drywall control joint might be the best search term.
This shows a top view.
http://tinyurl.com/arxp3rn

I've never seen them anywhere. Just got curious.

[benick]

"Robert Macy" <robert...@gmail.com> wrote in message
news:89bdbdbc-3ead-44d8...@u19g2000yqj.googlegroups.com...

I have been in the drywall business for some 30 years so I'll toss out a few
suggestions...With a run that long you are probably crossing a structual
beam , post or whatever..Which is fine if you run the 12 foot sheets
horizontal and make sure the stress point is in the middle of the sheet but
I'm guessing the sheets are run vertical or if the sheets were run
horizontal there was a floor to ceiling butt joint put there..Either way
you're screwed so to speak and not even Durabond is gonna help..Here is what
I would do..

Cut the drywall back a few studs on either side of the crack and span the
stress point with new drywall..Mud the 2 new butt joints and paint..To much
work ??Construct a false beam by screwing 2X4s or whatever you want or have
laying around to the wall, sheetrock , add cornerbead and mud...To much work
?? Buy some trim boards and moulding and build a false beam over the
spot..Still to much work ?? Buy a 1x4 pine board , nail it to the wall
covering the crack and paint it...HTH...

[k...@attt.bizz]

On Tue, 8 Jan 2013 18:40:55 -0500, "benick" <ben...@fairpoint.net>
wrote:

Paint a mural of the Parthenon on the wall. If you don't want to fix
it, feature it.

[DanG]

You end up with a visible, straight line, joint in the wall much like
tooled expansion joints in concrete.

[Robert Macy]

On Jan 8, 4:40 pm, "benick" <ben...@fairpoint.net> wrote:
> "Robert Macy" <robert.a.m...@gmail.com> wrote in message

Thanks for all the good suggestions. The sheets are horizontal. I
actually was originally leaning toward putting something that looks
like it 'belongs' on the wall at that location, but since had
forgotten. Think I got used to the 'clean' look.

What is irritating is is that *IF* the tape were 3, or even 4 inches
wide, I think the joint would have remained invisible. The tape simply
ripped loose on one side and then transferred the crack to its edge.
Where the tape did not come loose [perhaps less tension on it] the
surface remained crack free.

Temperature did have a lot to do with the crack formation. the room
originally set around 90 degrees [i'm old] but now is isolated and has
dropped to around 60 - that's when the cracks showed up with a
vengence. But, while I've been working in that room, the temp has gone
up to around 70 and some of the cracks have turned 'invisible' again.
But, must make certain that they cannot form, else they permanently
will show [until re-re-repair] Perhaps if I repair this wall in a COLD
room, then when the heat comes back, the tape and mud will take the
compression better and no crack will form? when it turns cold again.

[dayum...@gmail.com]

[page...@gmail.com]

The human hair is 3/1000 of an inch far less than a single mm. I am having the same issue on a ceiling seam, but the contractor before me used 1/4" drywall and I am loathe to tear it down and do it in 1/2"

I am a applying a second layer of paper tape after sanding a large portion of the mud down.

Updates will follow