Panic or no? Rafter scare today

[MatBirch]

Had a bit of a scare today. My son was home alone and texted me saying that there was a big crack in the ceiling in one room. He then proceeds to tell me that he heard a load noise like "the house settling a lot". My wife was able to come home, and did a video call with me and walked the house. There are several long cracks in the plaster running perpendicular to the rafters across one whole half of the house. I'm home now, and went up into the attic, and all looks just fine. I wasn't up to digging out blown in insulation, but all the rafters, collar ties, purlins, and braces are still where the should be, the insulations isn't disturbed... Everything looks just fine.
The house was built in 1905. Shouldn't be a whole lot of "settling" anymore. I've checked several times throughout the day, and there's no news if any seismic activity. I looked over the basement, and all looks fine as well.
Any thoughts?

 

[PWC Repair]

If a main beam UNDER the house broke. OR, piers have settled down without being re-shimmed, I could see enough sag to cause perpendicular cracks. I'd be concerned enough to either find the cause or get a pro in ASAP to find it.

 

[FMB4]

Many houses built in that era need shimming, bracing, and/or lifting-support via foundation jacks. My Grandmother's house was probably built in the late '20s and it had several foundation jacks on one end of the house (this was in the '60s). I too would bring in team of pros before things get even worse.

 

[BillK]

It does look like there were a couple of quakes a day or two ago a little north of you.

Real-Time Earthquake Map

 

[TMcCay]

Time to call in a pro. And I would start at the bottom of the house also.

 

[Innovate1]

Very recently had a friend with a very old house that had a crack in the plaster in one bedroom. I went up in the attic and found the framing fine. The plaster was pulling away from the framing. Not sure why it didn't fall completely. I think the light fixture was helping hold it up. :0 You might want to dig into the insulation and see if the ceiling is still tight to the framing. They got someone to fix it - not sure exactly what they did. I was thinking of jacking up the ceiling and adding a bunch of screws. Think it had nails.

 

[wrenchguy]

Rafters?

 

[billconner]

I suspect he means ceiling joists?

Compare the area of perimeter foundation walls and typically piers along center of house, along with tributary area, and easy to see why they sink more.

Use a level or a marble on hard flooring and see if or how much it slopes to center. It can be leveled - slowly.

 

[Bucko]

How old is your son and is there a chance he was "exploring" the attic and didn't know where it was safe to stand. When I was a kid me and my friends had "forts" in the garage rafters we would climb up in before school.

 

[58Yeoman]

I bought an English cottage style house in '99, and it was built in 1936. Brick on the outside, lath and plaster inside. There was a crack in the foyer running horizontal. One day we had a tremor and I heard a loud crack. That crack had closed up.

 

[Jackfre]

You might consider getting a laser level and taking some readings making note of the result for later comparison. At the very least that will allow you to see if things are changing over time. Roll tests on the floor are good to.

 

[CraigStu]

I think I remember that Innovate's story of plaster pulling away is similar to a thread here a month or two ago. I will hope that is what this thread turns out to be about since it is probably the least problematic cause possible.

 

[crazylunker]

any termite trails on the foundation or supporting beams/joists?

 

[egdede]

I have some experience in the region and was surprised at what the local called 'plaster' on those older homes. Seemed more like lime based mortar (like cement). Heavy heavy compared to wood lathed plaster I see in similar aged homes in Southern CA. Many problems in the home I worked on because big slabs of that 'plaster' had separated from the lathe.

 

[FredWanaker]

Idaho does get earthquakes, and some are recent but IMHO not strong enough to cause the problem. I'd sit down with my son and explain the importance of being 100% accurate on explaining where he was, what he heard and felt. Were it me, Unless your son says he was walking in the attic and slipped, I'd be finding the best home inspection guru within 100 miles of me and paying for a home inspection, starting with the foundation and ground below.

 

[Karl1163]

if it's the south side of the house, it might be that the cracks were there before and they open and close with the seasonal temperature and humidity changes? if it were only one room, I'd suspect plaster coming loose from the lath, but not really a whole side of the house. You can check for that by using a taut line or long straight edge (strip of plywood) to see how much the ceiling is bellied- a little is normal, over an inch may be a problem.

 

[mcbane]

Is the crack in plaster that is level, that is, the underside of your attic floor? Or is the crack in a sloped surface along rafters that extend below the ceiling surface? Or is it near where the horizontal ceiling surface meets the sloped surface of the rafters?

 

[FMB4]

Yep, ID has experienced a lot of small/minor earthquakes and aftershocks during the last number of weeks. Our Australian Sheppard has been acting very much unlike his typical goofy self.

 

[wssix99]

Time to call in a pro. And I would start at the bottom of the house also.

+1. Did you have any high winds lately? Regardless, those cracks are a sign of a failure somewhere. Time to call in an engineer, find the failure, and fix it.

 

[engineer2]

I could be wrong, but I wouldn't think termites are a problem in Idaho.

Get up on a ladder and sight along the ridge of your roof. If you see a sag, that could be part of the problem.

 

[larry_g]

Had a bit of a scare today. My son was home alone and texted me saying that there was a big crack in the ceiling in one room. He then proceeds to tell me that he heard a load noise like "the house settling a lot". My wife was able to come home, and did a video call with me and walked the house. There are several long cracks in the plaster running perpendicular to the rafters across one whole half of the house. I'm home now, and went up into the attic, and all looks just fine. I wasn't up to digging out blown in insulation, but all the rafters, collar ties, purlins, and braces are still where the should be, the insulations isn't disturbed... Everything looks just fine.
The house was built in 1905. Shouldn't be a whole lot of "settling" anymore. I've checked several times throughout the day, and there's no news if any seismic activity. I looked over the basement, and all looks fine as well.
Any thoughts?

When was the last remodel, add-on, or work done on the house? What is the land your setting on, side of a hill, in the wetlands, riverfront, anything there that could contribute to movement? Take in the whole setting and the last change, don't just focus on one thing that it could be.

lg
no neat sig line

 

[MatBirch]

Ok- try to answer a few questions.
NO way my kid goes up in the attic. He’d have to go out to the shed, drag the step ladder in... then here’s no room for the 8’er, so you have climb to the very top osha step, then pull yourself up... lol
The ceilings are all flat
The last remodel was likely sometime in the 80s.
The ground here is hardpan clay. High desert, very little moisture.
No termites

I’ve now spent a good couple hours in the basement. Scrutinized everything with a nice brite flashlight. The overall span about 15’ with original 2”x6” floor joists, on 24” centers. There is a 5x8 beam (oddly oriented flat) at mid span. It rests on a pony wall on one end, has one center post 2-2x4s. And an end post. Span between posts is only about 7’. Each end of the floor joists sit on concrete. Exterior foundation wall, and center concrete pony wall. There is of course blocking of some form or another under the joists, and it all looks solid and in tact. Other than old, and one broken subfloor plank, everything looks good. Posts and beam are solid, concrete all looks good, no cracking. The slab in fact is in amazing condition for it’s age! Walls are spalling on the exterior wall, and is on the list to fix. I think there was a drainage issue in the past.
All in all, I’m still stumped. I’ve been in the construction industry in some form for nearly 35 years, and know my way around most structural issues. I’m new to old construction techniques though. Balloon framing, rafters instead of trusses, lathe and plaster, etc. Even with my lack of experience, I have to say everything looks fine.

 

[egdede]

Is your plaster more like stucco than drywall mud (hard and heavy)? I know homes in Wendell, Jerome and Shoshone that were plastered on the inside with a plaster that, as I posted above, is very very heavy. Once the keys break off it can fail in large slabs.

 

[BillK]

I know that you are all discounting seismic activity but the one site I linked to showed a 3.7 quake around 100 miles from you around that time ? When Mineral Virginia had their 5.8 around 10 years ago it cracked open 2 corner drywall seams in my house and I am over 100 miles away.

Would love to see a picture of the crack.