Why did the ceiling sink, took down interior wall

[skorpion_]

I believe that these W-trusses are supposed to be self-supporting, but they still "benefit" from having support underneath to prevent sagging over time.

One thing you can do to be a bit more sure is to place a glued laminated timber beam in the attic, whose ends rest on 2 trusses that are still supported by a wall, and the remaining trusses (where the wall has been removed) can "hang" from the beam using suitable metal supports.

 

[AG A]

What does the building specifications say next to the drawing? Because it states how the different building elements (load-bearing, non-load-bearing wall, etc.) should have in terms of dimensions/construction.

I suspect it is not structurally load-bearing based on the description given by TS on the construction. 10mm of more deflection is not much when the span becomes much longer. As already mentioned, it is okay with a deflection of L/300 in most cases, roofs that are not connected with floor structures are sometimes even approved at double that, L/150.

What we haven't done is any load calculation. What loads is the house dimensioned for, and what loads were present during the demolition. A winter is coming, with up to a couple of hundred kilos of snow per square meter. How would that have affected the deflection?

 

[orienterarn]

Another question about a load-bearing wall, I'm in the process of taking down the wall between the kitchen and living room. I and several others assessed the wall as non-load-bearing. The house is a Gullringshus from 1966. The wall is longitudinal with the roof ridge. The distance between exterior walls is 7.4m. The only walls I can find that are marked as load-bearing in the drawings are the basement walls.

I have trussed rafters and the studs in the wall were, in my opinion, very weak, 50x35mm. The distance between the studs was also over 100 cm in one place, none of the studs were centered with the floor joist. The wall was between 2 door openings and ends with an opening of 4m.

Upon demolition, there was pressure on the last stud closest to the exterior wall, but when sawed, the stud easily broke and the ceiling dropped about 10 mm. The ceiling is now supported to the height before demolition. So my question is, did the wall have a load-bearing function, or is it normal for the ceiling to sink slightly over time?

It's a heart wall, meaning load-bearing, and not self-supporting trusses as clear as day.

 

[sunds14]

The wall you demolished is drawn on the section drawing (the one with the house in cross-section viewed from the gable), and usually only load-bearing walls are. Now, the wall in question is not exactly in line with the heart wall/wall in the basement, but it still makes one a little suspicious.

You have probably misunderstood everything a drawing contains. Section drawings show both load-bearing and non-load-bearing walls. It is the floor plans and section drawings needed when applying for building permits. The building permit officer should be able to see inside the house. Construction drawings (K-ritningar) usually only show walls that are part of constructions. Construction drawings should also be present at the start meeting. That the truss sags 10mm when you remove a non-load-bearing interior wall is quite normal. When we build houses, the interior walls are usually in place before we lay roof tiles, so a sag in the truss when removing the interior wall is quite normal.

 

[BryggArk]

Yet another question regarding load-bearing walls, I'm in the process of taking down the wall between the kitchen and living room. I and several others assessed the wall as non-load-bearing. The house is a Gullringshus from 1966. The wall runs parallel to the ridge of the roof. The distance between the exterior walls is 7.4m. The only walls I can find marked as load-bearing in the drawings are the basement walls.

I have truss roof joists and the studs in the wall were, in my estimation, very flimsy, 50x35mm. The distance between the studs was over 100 cm in one place, none of the studs were centered with the floor joist. The wall was between 2 door openings and ends with an opening of 4 m.

During demolition, there was pressure on the last stud closest to the exterior wall, but when sawn, the stud snapped easily, and the roof dropped about 10 mm... the roof is now propped back up to its height before demolition. So my question is, did the wall have a load-bearing function or is it normal for the roof to sag slightly over time?

No, the wall is not load-bearing simply because it is included in the drawing and/or because there is a wall in the basement directly below. The basement wall supports the floor, which is not a truss construction and hence has a maximum span of about 4m. The drawing merely indicates where the wall is located. Given the flimsy studs, it can't be load-bearing. The truss should support that span unless it is under-dimensioned. If the wall were load-bearing, the truss's braces would connect to the wall, as they do on the other side where the truss also extends slightly over the patio.

But why did the roof sag? It's hard to say. Perhaps the builder pressed the truss up too much during the construction of the house? It becomes stable if you press the studs between the floor and ceiling. With the sagging, the truss may be returning to its intended original form. Have you checked with a level to see if the roof is leaning or not?

Finally: A wall with standing wood studs can indeed have a load-bearing function, even if it wasn't intended to be.

 

[Sir Duke]

Finally: A wall with vertical wooden studs does have a load-bearing function, even if it is not intended as load-bearing.

Good point, I didn't see that mentioned earlier!

Anything that has contact with both floor structures contributes to the total load-bearing capacity of the construction. Even if it is not load-bearing in the sense of indispensable for the construction's integrity.

 

[Byggahus48]

Yet another question about a load-bearing wall, I'm in the process of taking down a wall between the kitchen and living room. Both I and others assessed the wall as non-load-bearing. The house is a Gullringshus from 1966. The wall runs lengthwise with the roof ridge. Distance between the outer walls is 7.4m. The only walls I can find marked as load-bearing in the drawings are the basement walls.

I have truss roof trusses, and the studs in the wall were, in my estimation, very weak, 50x35mm. Even the distance between the studs was over 100 cm in one place, none of the studs were centered with the floor joist. The wall was between 2 door openings and ends with a 4 m opening.

During demolition, pressure was put on the last stud closest to the outer wall, but when sawing, the stud broke easily and the ceiling sank about 10 mm.. the ceiling is now supported to the height before demolition. So my question is, did the wall have a load-bearing function or is it normal for the ceiling to sink slightly over time?

🤔 Is this an example of penny-wise, pound-foolishness? When you don’t let a building expert evaluate BEFORE YOU HAPPILY REMOVE A WALL? It might come as a surprise, but not all houses are INTENDED to have an open floor plan. This is a new trend, but many houses can't achieve this without load-bearing beams, etc.
🤔 I get uneasy reading the forum here, seeing how people with little or no knowledge demolish and remodel. I assume you haven't even been to the building committee to discuss your “new solution.”
🤔 Or checked with your insurance company regarding how they feel about a total change in the load-bearing structure of the house. One thing to be aware of is that if the house settles or the roof collapses due to your renovation, you WILL NOT receive any compensation!
🤔 Maybe the house can handle this right now, but add half a meter of wet snow, and that could be what causes the house to "collapse."
🤔 Somewhere, I hope this is a “troll-writer,” but I fear this is a guy who thinks he can fix most things with a “chainsaw, hammer, and nails.” There’s a reason it takes several years to train as a structural engineer at a college level…
🤔 My advice, if it’s not already too late; put the tools down (you’re not as skilled as you think). Contact a structural engineer and have them calculate the beam dimensions that the house needs to have an open floor plan.
🤔 This is not something you can take a chance on!

 

[lärjungen]

Now concrete tiles aren't much heavier than clay tiles, as has been widely discussed here on the forum.

It depends a bit on the manufacturer. Benders Palema Benderit 2-cup concrete tiles weigh 38.8 kg/m2 while Vittinge classic T11 2-cup clay tiles weigh 30.8 kg/m2. On 150 square meters, that's 1.2 tons more weight with concrete tiles. Admittedly spread over the entire roof surface, of course, but it's still quite a weight difference on paper so to speak.

 

[Sebyhed]

Another question about load-bearing walls, I'm in the process of taking down the wall between the kitchen and living room. I and several others assessed the wall as non-load-bearing. The house is a Gullringshus from 1966. The wall is longitudinal with the roof ridge. The distance between outer walls is 7.4m. The only walls I can find marked as load-bearing on the plans are the basement walls.

I have truss roof supports, and the studs in the wall seemed very weak to me, 50x35mm. The distance between the studs was over 100 cm in one place, none of the studs were aligned with the floor joist. The wall was between 2 door openings and ends with a 4 m opening.

During demolition, pressure was applied to the last stud that was closest to the outer wall, but during cutting, the stud easily snapped and the ceiling sank about 10 mm... the ceiling is now supported back to the height it was before demolition. So my question is, did the wall have a load-bearing function, or is it normal for the ceiling to sink somewhat over time?

I live in a similar Gullringshus from 1963. Here, the corresponding wall is opened about three meters but it is reinforced up in the attic, from the outer wall to the chimney, as the carpenter assessed it as load-bearing. (Previous owner.)

 

[Shaft1]

Yet another question about a load-bearing wall, I am in the process of taking down the wall between the kitchen and the living room. I and several others assessed the wall as non-load-bearing. The house is a Gullringshus from 1966. The wall is longitudinal with the roof ridge. The distance between the outer walls is 7.4m. The only walls I can find marked as load-bearing in the drawings are the basement walls.

I have truss rafters and the studs in the wall were, in my assessment, very weak, 50x35mm. Even the distance between the studs was over 100 cm at one point, none of the studs were centered with the floor joist. The wall was between 2 door openings and ends with an opening of 4 m.

During demolition, pressure had been applied to the last stud that was closest to the outer wall, but upon sawing, the stud easily broke and the roof sank about 10 mm. The roof is now propped up to the height before demolition. So my question is, did the wall have a load-bearing function or is it normal for the roof to sag somewhat over time?

You have removed a load-bearing wall.
Support with a beam and distribute the forces. There is a solution, but hire a professional to calculate the beam dimension for you.

 

[useless]

It depends a bit on the manufacturer. Benders Palema Benderit 2-cupped concrete tiles weigh 38.8 kg/m2, while Vittinge classic T11 2-cupped clay tiles weigh 30.8 kg/m2. On 150 square meters, it becomes 1.2 tons more weight with concrete tiles. Admittedly spread over the entire roof area, of course, but it's still quite a weight difference on paper, so to speak.

At the same time, the roof should be designed for a snow load of 2-300 kg, so those 8 kg/m2 are less than the margin of error.

 

[Klag]

I interpret the drawing as if you have removed this wall:
[image]

And it is presumably needed to support the roof trusses somewhere in the middle of the house.

A so-called Swedish trussed rafter like this cannot be supported by a load-bearing wall in that position on the bottom chord. The settling is likely due to the truss not being assembled with the camber that is so clearly required on the drawing with bold capital letters.

 

[Kane]

It is a heart wall, meaning load-bearing, and there are no self-supporting roof trusses, it's very clear.

What do you base that on?

 

[GoC]

That's a load-bearing wall you have removed.
Support with a beam and distribute the forces. There is a solution, but hire a civil engineer who can calculate the beam's dimensions for you.

No need for a civil engineer to calculate a truss like this.
That was taught in high school in the 80s.
Just dust off your knowledge of Cremona's force plan and calculate the bearing capacity and deflection of the truss that the roof truss constitutes.

 

[GoC]

It is a heart wall, therefore load-bearing, and not self-supporting roof trusses any clearer than that.

Have you heard of buckling?
A wall meant to have a load-bearing function would not likely have been designed with sparsely set 2x3” studs, as they wouldn't serve any purpose in handling the compressive loads down the wall.