I appear to have a crack on my drywall where it meets the ceiling in my bedroom.

The crack is spreading a bit. I went in the attic and noticed that this rafter beam is cracked and might be causing the ceiling in my room to lift? I'm not 100% sure what's going on here.

But on my other side of the home I'm developing a crack running down my ceiling. On this side of my home I noticed a few truss mending plates have come undone against the rafter.

I'm in Sacramento so we suffered a 5 year severe drought only to be completely drenched this past winter. Now that we're in the middle of Summer were experiencing a ton of heat and our clay soil is cracking all over our yard.

Wondering what's the best approach to repairs at this stage. Do I have foundation issues? Or is it just some wood expansion and shrinkage that's pulling my drywall apart. Do I patch the drywall or call a foundation expert?

This time of year last year I do have some door frames that go out of square leading to minor adjustments and it's been this way for the last two years I have lived here.

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More pictures enter image description here enter image description here enter image description here Edit: These are extra pictures, as you can see in the picture 1, ignore the temporary patch job, but the wall and the ceiling have a split and it crossed that piece of drywall, behind the wire for the lamp I put up is a gap about 1/2" wide. You could literally push up on that ceiling piece with your hand and it'll go up.

Picture 2. On the opposite side of the house, in the living room is that straight line crack that is crawling down from the ceiling.

The final picture is just a different part of the house where there are signs of bad drywall patch jobs that were done before we moved in that are starting to show more, like drywall tape that seems to be cracking.

2 Answers 2


The split top cord should be repaired. Lay a 6 or 8 ft long 2x4 or 2x6 across 3 or 4 of the bottom cords, then use a length of 2x4 to push up to close the split. When it is aligned properly, nail it in place with numerous nails that are the type that do not causing splitting. Then sister on 3 or 4 ft (or more) of 2x4 on one side of the repaired section. If protruding roofing nails prevent sistering on either side, then you might have to use a 2x3 on the side and on the bottom edge.

(You might squirt wood glue into the crack before pressing the crack closed.)

  • 1
    So using a 2x4 or 2x6 I'm creating a floor to use as a jack to lift my cracked rafter up til it reconnects before mending it with nails and sistering it. Is it something that can be done on my own as far as the weight loaded on top of the roof? I know there's nothing above it but a shingle roof so just thinking about the amount of force I'll need to exert. And also thank you for the tips.
    – HarrisonT
    Commented Jul 28, 2017 at 23:12
  • In most trusses the top cord is in compression. It is possible that pushing up will force it out of alignment. If that happens, you might have to attach a guide to one side of the top cord. Commented Jul 28, 2017 at 23:17
  • I doubt that you would be able to force it back in place with one hand while nailing or screwing with another. At the suggestion of an experienced builder who had started as a framer I used this technique to push up a section of roof decking before putting in blocking to hold it up. It takes a lot of force to shift framing members. When your (out of plumb) vertical brace is snug by hand you will be required to tap (or pound) on the horizontal 2x6 to shift it to raise the split top cord into place. It will take at least 100 lbf to close the split and hold it in place while you nail or screw it. Commented Jul 28, 2017 at 23:44
  • Are there any videos on YouTube which could show me some techniques to push up properly. Funny thing I think you answered my previous question about fixing a retaining wall as well, Jim S.
    – HarrisonT
    Commented Jul 29, 2017 at 0:22
  • I don't know of any Youtube videos on this. In my own case I positioned the 2x6 across the bottom cords (celing joists) and happened to have a length of 2x4 that I positioned at an angle along the 2x6 such that when I pounded it with a hammer (on the bottom) the bottom slid along the 2x6 becoming more upright and so raising the roof decking which had sagged. IIRC the 2x6 did not move or at least very much. Commented Jul 29, 2017 at 0:30

I agree with @Jim Stewart , it needs to be fixed.

However, I think I'm missing something. The trusses on the left side of the peak are different than those on the right side. Is there a reason for this? Maybe this is causing the cracked ceiling and the door problems.

If the ceiling is cracked EXACTLY where it meets the wall, then it could be from 1) lack of attic ventilation, or 2) lumber that was installed "green" and shrunk over time when it dried out.

1) I don't see any soffit vents. They're needed and you need to verify why you don't have them...maybe other vents somewhere?

2) Look for a grade stamp on the HORIZONTAL lumber near where the ceiling is cracked. If it's marked, "Grn", this means Green lumber was used. (If the ink in the grade stamp is smeared, this means it was wet when they applied the grade stamp and it is definitely "Green".

I doubt the foundation is the problem, unless you have wall cracks too, (I.e.: cracks in wallboard at the corners of doors and windows).

  • As far as I can tell I don't have any soffits outside, let alone soffit vents. There are these chimney like vents up on the roof itself, there are two of those. I can't get to the horizontal lumber near the part of the cracked ceiling because it's pretty tight down there, I got a pretty high pitch, never really measured it but it's at least 6/12 I'd say. I think the reason it's different on both sides of the trusses because one side has a higher vaulted ceiling than the other side. I'm getting the crack in the same center area on both sides of the house. The house was built in 83
    – HarrisonT
    Commented Jul 29, 2017 at 5:45
  • @HarrisonT If you don't have cracks at the corners of your doors and windows, then it's not the foundation. Hmmm...no vents?? Soffit vents allow "cross ventilation". This removes moisture from the attic and helps prevent dryrot. Plus, it helps cool the attic. Where you live, you don't have snow, so you won't have a failure until you walk on the roof.
    – Lee Sam
    Commented Jul 29, 2017 at 6:23
  • Do I need to concern myself that some of those staple like plates are coming undone? I'm going to perform the sister method Jim suggested as soon as I can get some help from my uncle who does his own work at home. So I'm confident he'll be more familiar with the whole sistering process.
    – HarrisonT
    Commented Jul 29, 2017 at 6:30
  • Yes. Those gussets are critical and handle much force. You'll need a very robust repair, such as 3/4" plywood gussets, twice as large as the steel ones, bolted and glued to each side.
    – isherwood
    Commented Jul 29, 2017 at 14:26
  • Could the gussets be glued and nailed or screwed? That would be a lot easier than bolting. Another way to pull the split top cord into place might be screws from below. I would try 3" or 3.25" long screws of the type which are optimized for clamping. These have a long unthreaded section next to the head so that it will pull a gap closed. If the screw is fully threaded all the way to the head it will not clamp as well or at all, e.g., decksdirect.com/… Commented Jul 29, 2017 at 14:41

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