Roof truss and possibly intermediate support

[viklon]

Hello,

We have a 2-story split-level house and we are considering opening up between the kitchen and the living room.

- The house is from 1981, and in the construction documents, there is a technical description that states that the load-bearing part is the exterior wall. There are no interior walls listed under the heading of load-bearing.

- Interior walls consist of wooden studs 35x70 mm.

- The attic is furnished but wasn't initially. However, a useful load was considered when designing the roof trusses.

- The interior wall we intend to remove is in line with the ridge and could provide support for the roof trusses. It looks like the interior wall we want to remove was installed after the ceiling was put in if that's a clue.

- The roof trusses have C/C 1200 mm and the span between exterior walls is 7800 mm.

- I don't fully trust the Technical Description because it states that the roof truss is a truss and that the upper chord is 45x145 and the lower chord is 45x170. On the drawing made by Bjerking, you can see that the lower chord is 45x220 and it looks like a frame truss. The upper chord seems accurate.

I want to trust the Technical Description but I'm getting very anxious because it seems that most frame trusses require an intermediate support, which is exactly what we want to remove. I can't discern from the drawing of the roof trusses if there is an intermediate support marked.

Any thoughts and ideas?
Thanks for the help.

Best regards,
Viktor

 

[Centano]

On the truss drawing and section drawing, it looks like the interior walls in line with the ridge are load-bearing.
It's probably best if you bring in an expert to make an on-site assessment.

 

[Plupp 618974]

Tricky. Contact a designer. Costs a bit but it costs much more if it goes wrong.

 

[viklon]

Thank you for your answers. You confirm my fears, but it's strange that you can't trust what's written in the papers. I will have to contact someone who can come and take a look at it.

Thanks again!

 

[RiKr]

There is no doubt that the wall is load-bearing, and it is required to be so given the design of the truss and the use of the upper floor.

 

[BirgitS]

- I don't fully trust the Technical Description because it states that the roof truss is a truss and that the top chord is 45x145 and the bottom chord is 45x170. On the drawing produced by Bjerking, you can see that the bottom chord is 45x220 and it looks like a frame truss. The top chord seems correct.

I want to trust the Technical Description but am starting to get very anxious because it seems like most frame trusses require an intermediate support, which is precisely what we want to remove. I can't decipher from the truss drawings if there's an intermediate support drawn in.

Frame trusses look like a W approximately. So what does it look like in the attic?
Something could have changed at the last minute, for example, if the buyer suddenly wanted an attic that can be furnished.

 

[viklon]

There are no inspection hatches in the wall panels in the attic, but the distance between the wall panels is 4 meters. This matches the design of the truss shown in the drawings, and if it were a truss structure, it should be visible in the attic.

When I look at tables for the dimensioning of roof trusses, it seems that almost all trusses require an intermediate support to achieve a span of 8 meters. Although the tables are for a roof slope of 45° and I have 30°, it is a good indication.

I have requested documents from the municipality for a house of the same type a bit farther away to see if there is an error there as well.

 

[BirgitS]

Once you get up into the attic, you can clearly see if there are truss roof trusses, as you usually can hardly get around other than in a narrow path in the middle. So it seems like you have frame roof trusses, and then it's true that a load-bearing interior wall is usually required roughly under the ridge.

As mentioned earlier, a structural engineer can help you with the sizing, etc., to offset the load-bearing wall so that you have enough basis for a building notification.

 

[qvirre]

Is it for aesthetic reasons that you don't want a beam in the new opening? Depending on the size of the opening, it is not that expensive/complicated to install a beam. It is very likely that the partition wall is load-bearing, so it's probably more cost-effective to spend the money on a beam rather than an investigation.

https://www.byggbeskrivningar.se/dimensionering/oppning-innervagg-1-12-planshus/

Enter your values here to get an idea of what dimension of beam you need.

 

[viklon]

Is it for aesthetic reasons that you don't want a beam in the new opening? Depending on the dimensions of the opening, it's not so expensive/complicated to install a beam. It's very likely that the partition wall is load-bearing, so it's probably more cost-effective to spend the money on a beam rather than an investigation.

[link]

Enter your values here to get an idea of what beam dimension you need.

Hi,

I don't mind a beam. My original question arose because in the old construction documents it stated that there were no load-bearing interior walls. It says that the exterior walls are load-bearing and that there are no load-bearing interior walls.

I thought it seemed strange, and you along with several other skilled forum members are also saying that the wall should be load-bearing.

Thanks for the tip. I'll check it out and see!