How to Repair Cracks from Truss Uplift
LESLIE: Keith in Illinois is on the line. How can we help you today?
KEITH: I have a one-and-a-half-story house that has a – on the second floor is the – well, the rooms are basically half-heights. They’ve got the – in the middle, they’re full height but on the edges, they’re not. That’s where the closets are at.
During certain times of the year, the trusses tend to expand and it lifts the drywall in the edges and causes it to curl along the seams. And the builder wanted to put crown molding up there to prevent that. And what I had wanted to do, obviously, was prevent the action completely. It had been recommended before to add ventilation above the attic to get good airflow through there. The builder has said that by adding additional venting, which would be – I would consider the side vents. He said that would actually ruin the venting system that’s already in place, which is in the eaves.
Do you have any additional recommendations for that?
TOM: Well, a couple of things. First of all, truss lifts happen when the trusses shrink and they pull up in the middle of the room and that’s why you get the ceiling cracks, correct?
TOM: And the ventilation you have right now, do you have continuous soffit venting?
TOM: And do you have ridge venting down the peak of the roof?
TOM: Well, you’ve already got the best ventilation system out there. So as long as it’s working properly, it’s not blocked, there’s no point in putting additional ventilation in there.
TOM: Now, is it possible for you to get above the trusses, down like right above the ceiling?
KEITH: Well, I can’t get above that area. I mean it’s boxed off and of course, they have it insulated but they do have the Styrofoam blocks that prevent the insulation from blocking the truss vent. No, unless I cut through the top of the roof, I cannot get above the ceiling there.
TOM: Well, if the trusses were installed correctly – which, of course, isn’t going to help you – there are some L-shaped truss clips that they would have installed that could have prevented this problem, that help as the roof expands and contracts. The reason I asked you if you could get to them is because they may be able – you may be able to install them after the fact.
But if you can’t get to them, then I’m afraid there’s really not an easy solution to this. If you were to add a second layer of drywall over what you have and you were very careful to make sure that the seams didn’t line up with the seams you have now, you may create a roof that’s strong enough – or a ceiling that’s strong enough – to not show cracks like it is. I would also glue the new layer to the old layer. But again, I would overlap those seams, so to speak. Does that make sense to you?
KEITH: Yes. So they don’t line up.
TOM: And that might make it strong enough. Because right now, there’s no strength in the seams; you know, it’s just the paper.
TOM: So that’s going to be the weakest part of the ceiling structure. If you were to put a second layer of drywall and glue across that, then I think you would have a really, really sturdy ceiling and it would be unlikely that it would continue to crack.
KEITH: If I could sand on the – because I can get in the attic and get up to where the 2x4s come together in the truss. Would I be able to screw in a bracket there? That’s what you’re suggesting to basically strengthen that joint?
TOM: Keith, if you can get on top of the drywall, so to speak, those trusses are going to be attached to interior walls in some places, correct?
TOM: So what you would do is you would have to detach them from the interior walls and you would put an L-clip in place of the nails. The clip is attached to one side; there’s a slot on the other. And that allows the truss to move up and down and it will relieve some of that uplift and cracking.
Now, when you do that, you might see – over the next year, if the truss starts to try to move again, you may see some nail pops that occur. And if that’s the case, you want to punch them up and through to kind of relieve the pressure and then patch the drywall.
But I do think by the time you go through all that work, that it might be an easier solution just to put a second layer of drywall on. Because your problem is primarily with the seams and that’s going to be the easiest way to fix that.
KEITH: Yeah, it does sound like it. Alright. Thank you very much.
TOM: You’re welcome, Keith. Good luck with that project. Thanks so much for calling us at 888-MONEY-PIT.