Contractor Talk - Professional Construction and Remodeling Forum banner
1 - 20 of 66 Posts

·
Registered
Joined
·
74 Posts
Discussion Starter · #1 ·
Hello All.

I am a professional builder.

Having build many new homes and cottages we are faced with a problem.

We use a very experienced drywaller.

On two of our last projects we have been plaqued with hairline cracks in the drywall and we cannot figure out why.

First project-

renovation
drywall cracked immediately after ceiling paint.
cracked on the original section of house not new addition.
ceiling was strapped on 12" centers
long cracks in the main areas...6 to 8' long.
building was heated and dry ( electric heat)


Second project

- New build
- Truss roof
- strapped 16" oc. Strapping was screwed up
- electric construction heat.
- Ceiling hairline cracked shortely after ceiling paint.
- Crackes were cut out and repaired.
- Just got a call from Owner that 6 or 8 cracks have re appeared.
- Went to look,,, house is at 32 % humidity which isn't too bad.


We are all stumped. Drywaller is stumped. I have had to cut out and repair and paint two full ceilings now and it getting expensive.

It looks like I will be re doing another full ceiling as well.

Drywaller has been fixing drywall no charge but I have bee paying for the painting.

To be honest we don't know really what to do or what is causing it.

Funny thing is it doesn't happen on most of the builds .

Drywaller says he has never seen it before.

Looking for discussion on this issue to try and get to the bottom of it

These two projects do not have much in common other then the drywaller, and supplier.

One was a winter build and one was a summer build.
 

·
Registered
Joined
·
2,716 Posts
A better description of the drywallers technique would help---paper or mesh tape?

Type of mud?

Screwing pattern?

Could be truss heave also---
 

·
Registered
Joined
·
74 Posts
Discussion Starter · #4 ·
Hi,

I will do my best. I am not a drywaller so bear with me.

This is what I know.

- 1/2 cgc.
- Prefill if necessary with 90
- coated with premixed mud in box cgc
- cgc paper tape.
- not sure on screw pattern but I know he prides him self in using lots of screws.

- I am not sure on the truss heave......my thoughts is this displays itself at the intersection of truss and top plate usually? Our problems is showing on the flats.
 

·
Registered
Remodel
Joined
·
31,084 Posts
Pictures would be good. That could happen if the strapping was too dry. It will pick up a lot of moisture once paint is put on.
 

·
Registered
Joined
·
74 Posts
Discussion Starter · #7 ·
Hi Guys,

I really appreciate all the brainstorming.

The current problem ( new home) was a summer build. Very little rain before the roof was one. Lumber is what it is. Bought from our local building center.

I have never heard of too dry strapping before.

There are now 5 or 6 cracks in the current problem home. cracks vary from 2 feet to six feet long.
 

·
Registered
Joined
·
1,978 Posts
I wonder if Lite dw compund was used in the last finishing coats ?

Lite is far more fragile than All Purpose mud. This in combination with high MC in the framing may have did it ?
 

·
Registered
Joined
·
1,978 Posts
Big builder - where are you located ?

You say strapping ? Was the strapping kiln died --- with the lumber stamped ? It could have been #2 or #3 grade not dried or stamped. This can be a problem ?
 

·
Registered
Remodel
Joined
·
31,084 Posts
Cracks at the edges or out in the middle of the ceiling?

Normally I'd think things were drying out or truss uplift, as mentioned. In this case, I got the impression that the cracks were along the tapers out in the ceiling, not edges.

The usual problem to see with strapping moisture content is too high of a content. In a reno where the ceiling is strapped, the strapping ends at the upper angle, and this is where you can get cracks when it shrinks.

If the trapping is too dry, it expands when it takes up moisture. Generally, the upper angles aren't cracked, but you can get some on the tapers.
 

·
Registered
Joined
·
74 Posts
Discussion Starter · #12 ·
Hello,

I will try and answer these questions.

These are all flat ceilings. No slopes or cathedrals. Has a tray ceiling but that area seems fine.

Yes is the graded and stamped SPF for framing. I am not sure if the strapping is graded and stamped but I highly doubt it.

We are location in Central Ontario , Canada.

Cracks are mostly in the middle areas, some extend from wall out into the main ceilings.

he uses the CGC lite. I discussed this with him and he drywallers says he has been using that for many many years and has never had problems before.
 

·
Registered
Joined
·
74 Posts
Discussion Starter · #16 ·
Again thanks everyone.

I don't think 5/8's drywall would have an affect on our problem.

Can someone clarify what APC is?

Thank you
 

·
Super Moderator
Joined
·
11,331 Posts

·
Super Moderator
Joined
·
10,672 Posts
All Purpose Compound.

Was the 1/2" used on 24" centers?. There tends to be a lot more movement in ceilings than there is on walls.
 

·
Registered
Joined
·
74 Posts
Discussion Starter · #19 ·
Hi Everyone.

Sorry about missing the APC thing ...

We will definitely try that.

Trusses are on 24" o.c but then strapped to 16" o.c with 1 by 4 strapping.

I guess it is definitely worth a try using the steel channel and regular mud.

We are framing a few right now so I want to not make the same mistakes again.
 

·
Particulate Filter
Joined
·
4,430 Posts
Rushing to paint over incompletely dry mud? Did you have a tight schedule on these builds that your crew was racing to meet?

I think I would try retaping the cracks rather than tearing it all down and starting over.
 
1 - 20 of 66 Posts
Top