I have torn down the knee wall now the whole house is thumping

[Nissens]

Even though the discussion has come to center around the serious side of the problem, i.e., weakening of the structure, it would be interesting if someone could provide an analysis of the original question, i.e., the bounciness and the acoustic aspect. Regarding stability, the basic structure already has features that make me wonder. With exterior walls protruding above the floor, there is a risk that the rafters/high beams (the diagonal beams) push the walls outward. With the floor integrated into the rafter as a bottom chord, one would get a much stronger structure and the rafter would essentially only transfer vertical forces to the wall. The disadvantage is, of course, that the upper floor is not as high. The collar beam naturally helps hold the structure together, but the collar beam is positioned quite high, so if the high beams are not rigid enough, they may tend to bend out into a split. The knee wall studs should also help stabilize this part somewhat but at the cost of high moments in their attachments and/or load on the part of the exterior wall above the floor. Unfortunately, I have a similar structure (which never had knee wall studs) in an older outbuilding. There, there is indeed a diagonal iron going from the floor beam to the wall plate, but there are still issues because the iron tends to lift and twist the beam (it is on one side of the beam and therefore twists it) while the top of the wall stud has come to be pushed outward.
Addition: saw that post 37 addressed roughly the same thing.

And why would one want to make the structure stronger? It's already strong enough...

 

[Bernt Ö97]

If you read up a bit on the construction of roof trusses and then look at the original poster's drawing again, you will have a completely different impression.

The original poster's drawing clearly shows that the walls in the attic spaces were a supporting part of the roof construction…

So you should be careful about giving advice if you have no knowledge whatsoever in the subject…

Correct
The support legs are part of the roof trusses and connect the upper arm with the lower arm (middle floor). Often the wall itself (against the attic space) is not load-bearing, in old houses often tongue-and-groove boards with chip-filling.
The advice to the original poster is:
Hire a knowledgeable structural engineer for on-site advice on how to restore the function of the roof trusses.

 

[AG A]

One thought, shouldn't the support legs be inside the wall that remains in the room?
Don't you usually see how the meeting where the upper rail and the lower rail meet in an attic?

Compare the photo with the sectional drawing, and you should realize your mistake. TS has also said that he has already demolished the attics, not that he is going to.

 

[Snigla]

The house has spoken... regardless of what may be right or wrong!

Make sure to understand the problem before the roof/rafters collapse if it snows. Considering your drawing... and where the support for the roof disappeared... I would be more worried about the roof leaning downwards towards the house...

Rebuild the structure... or look into what alternatives exist to support the roof/rafters... (a bit of calculation might be needed to sort it out... but if it's so important to have it completely open, it might be worth hiring someone for structural drawings (who can do some calculations on necessities, etc.)

There are other options too... where you can combine built-in storage with studs and support... (just a little tip)

 

[DrDengrot]

Where do you get the idea that there would be diagonal support legs?

Otherwise, I agree with everyone else, restore it or bring in an engineer/designer as soon as possible.

I interpreted post #61 as if the sketch was about the OP's house. But maybe it was a response to them?

 

[matsgran]

Hello, so here's the house design, so it feels like there's something to it.

The problem that I see is that the pressure on the outer walls outward has increased significantly, so the risk is that they might bow out, hence the sounds you hear! Hope it gets resolved.

 

[Saxdaling]

Hello!

How can one even come up with the idea of removing a load-bearing wall? If you get a heavy snow load, the entire roof will definitely collapse! If you want a beam, you should get help with the sizing. It may need to be really substantial depending on how long the span is. And attach it to the outer wall with a joist hanger and at the other end in a wall that is supported in the floor below. I hope you manage before it collapses.

We have bought a 1950s wooden house that we have renovated.
One thing we have done is remove the eaves to get "bigger rooms."

BUT

When you walk upstairs, it "thumps" a lot. (it didn't do that before)
The closer you get to the demolished eaves wall, the more it thumps.
(it thumps when my 4-year-old walks up there, and we're sitting downstairs, so it's very sensitive)

The beams are very substantial; I tried adding even more battens in between, but it didn't work.
Now I'm starting to think that the eaves walls had a function that pressed down the beam running along the house's long side and thus made it "stiff."

In the places where we still have the eaves, the floor is perfect.
Has anyone experienced the same thing?

My thought is to put up a couple of hefty battens that "press down" this beam at the wall sides.

Or does anyone have a tip?
I would be very grateful for it.

Here is a picture when the floor is open, and the green line is where the eaves used to be.

 

[heimlaga]

Prop up the roof with supports and wedges, then rebuild what you've torn down and it will be fine!

The other alternatives are significantly more expensive and labor-intensive.

 

[mangebest]

hi. can recommend this video:

 

[Nissens]

Correct
The support beams are part of the roof trusses and connect the upper frame with the lower frame (between floors). Often the wall itself (toward the attic) is not load-bearing, in old houses often made of tongue-and-groove boards with wood shavings.
The advice to TS is:
Consult a knowledgeable structural engineer for on-site advice on how to restore the function of the roof trusses.

Yes, the support beams in attics are load-bearing. That's why they exist. They likely also stabilize the floor structure, but I know less about that myself. The video in the message above says that the "support beams" also hold up the lower frame, and that sounds reasonable.

You surely have upper and lower arms, but houses don’t have those; they have upper and lower frames…

 

[star_daddy]

Support legs are part of the roof truss construction. Must be addressed immediately before the next heavy snowstorm. The snow load on your roof can be 20-30 tons or more depending on where you live

Looking at the drawing, you can see that the vertical strut, which also serves as a wall stud in the uppermost room, relieves the outer frame almost in the middle. This is the most effective place, as the deflections on the upper and lower frame become significantly smaller than if the strut were located elsewhere or completely absent. If you move the strut outward, the deflection in the upper part of the frame increases, and if you remove the strut, the standardized snow load plus the weight of the roofing will likely be able to break the frame according to calculations.

There is a possibility that the trusses are more numerous and therefore closer together than today's norm of 120 cm. In that case, the load can be slightly reduced. But even if you follow the norm, there is not much load you can have on the lower frame, that is, the floor of the upper room, and it is not surprising that the inquirer notices that the floor is shaky.

I usually recommend builders to add extra floor joists between the trusses, i.e., c/c 60 cm. In the outer wall, the studs are already c/c 60, so it often matches well; the vertical outer wall studs that are lost at door and window openings are moved to either side of the openings as reinforcement for the first shortened stud and create a support for a laminated beam that bears all the loads over doors and windows from the roof and upper floors (of course, this must be calculated).

 

[SueCia]

But....

it has already been established that TS is a troll who creates similar threads now and then and abandons them.

 

[Hybro]

Fytterackern, as the norbaggen would have said.

 

[DrDengrot]

They apparently managed well without computers when calculating sustainable roof structures even 70 years ago.

Yes, because the principle used is the same, the only difference is that the rather large systems of equations that need to be solved to determine the dimensions are solved in seconds by computer. It can take a couple of days manually if it is to be optimized....

 

[heimlaga]

No, I don't think he's a troll. Rather a consequence-fearing person who is fleeing, I believe.