Switch off heart wall in the attic

[Marcello]

View attachment 673699 Hello!

In my house, there is currently an opening in the central wall that I would like to open a bit more. I don't know if the existing opening is reinforced in any way as I haven't started demolishing yet. I want to open up the wall all the way up to the ceiling, so any existing reinforcement I intend to remove if it exists. In its place, I want to reinforce over the rafters in the attic with a 90x225 glulam beam. The span of the rafters is about 8m, that is 4m on each side of the central wall. I don't know the dimensions of the collar ties, but the rafters are 45x145.
Preliminarily, it will probably be three rafters that will be reinforced, and the glulam beam will rest on each "supporting" rafter alongside these three, so a total of five rafters will be involved.

Attached is a sketch of the floor plan where I've drawn how I want the walls, along with a somewhat poor image of the rafters. I don't know the dimensions of the collar ties, but the rafters are 45x145, C/C spacing varies between 900-1150mm. The roof pitch is about 30 degrees.

There are two questions:
1. Is it enough to have two "supporting" rafters to reinforce the three that will lack support from the central wall?

2. What type of fastening should I use between the glulam beam and the reinforced rafters to bear the tensile forces? Are forked anchors sufficient, or are they too weak?

Thanks in advance.

Best regards, Marcello

 

[Daniel 109]

It's not the roof trusses that should support the load distribution. It's support from underneath.

 

[Marcello]

It is not the trusses that should bear the load. It is the support from below.

And that is how it will be, the support from below will come from the trusses on the side that still lean on the load-bearing main wall.

 

[BirgitS]

It sounds like you need to hire a structural engineer who can assess on-site how it can be resolved and calculate the required dimensions so that you have enough information to submit a building notification to the municipality.

 

[BirgitS]

And so it will also be, the support from below will come from the trusses on the side that still lean on the load-bearing heart wall.

Which means that the heart wall may need to be reinforced and become thicker closest to the opening, which in turn may lead to a need for reinforcement on the floor below.

 

[Marcello]

Which means that the heart wall may need to be reinforced and become thicker near the opening, which in turn may lead to the need for reinforcement on the floor level below.

I have planned to reinforce the heart wall, so it will not be a problem. The wall is directly above a concrete wall in the basement, so the floor/level below probably doesn't need any action. Thanks for the answer.