2,364 views ·
4 replies
2k views
4 replies
Switch load-bearing wall with point load 26kN
Hello
I have a project where I intend to remove a load-bearing wall and am investigating how it must be supported. The wall supports a beam/floor structure and is also subject to a point load of 26 kN.
The span is 240 cm, and the point load of 26 kN comes about 100 cm into the span. In addition, the floor structure is designed for 500 N/m2 + 1 kN variable load.
I have been in contact with an engineer who revised his calculation after the discovery of the 26 kN point load. I still feel a bit worried and would like a "second opinion." It's especially the point load that makes me unsure. Below is the engineer's calculation for the support.
Factors,
The floor structure is designed for 500 N/m2 + 1 kN variable load.
Load case, simply supported beam.
Span, 2,400 cm
M= 1410 kNcm
Wx= 470 cm3 (required section modulus)
Glulam beam 90x225 has Wx = 759 cm3.
S-factor=759/470= 1.6
Bearing pressure.= 14.1 kN / 50 cm2= 282 N/cm2
Regards
Richard
I have a project where I intend to remove a load-bearing wall and am investigating how it must be supported. The wall supports a beam/floor structure and is also subject to a point load of 26 kN.
The span is 240 cm, and the point load of 26 kN comes about 100 cm into the span. In addition, the floor structure is designed for 500 N/m2 + 1 kN variable load.
I have been in contact with an engineer who revised his calculation after the discovery of the 26 kN point load. I still feel a bit worried and would like a "second opinion." It's especially the point load that makes me unsure. Below is the engineer's calculation for the support.
Factors,
The floor structure is designed for 500 N/m2 + 1 kN variable load.
Load case, simply supported beam.
Span, 2,400 cm
M= 1410 kNcm
Wx= 470 cm3 (required section modulus)
Glulam beam 90x225 has Wx = 759 cm3.
S-factor=759/470= 1.6
Bearing pressure.= 14.1 kN / 50 cm2= 282 N/cm2
Regards
Richard
What type of floor structure is it, he has calculated with very small loads?
The support force basically indicates that only the point load from the floor structure is included...
The support force basically indicates that only the point load from the floor structure is included...
Hello
First, I want to say that I am a layman, not familiar with all the terms and have been Googling intensively recently to somehow verify the calculations I have received and also make them match the information I read on various forums and specs for materials (glulam beams in different dimensions). My feeling also tells me that the forces the engineer has calculated are still too small, but I don't know.
As an addition to my first description, I can say that the load-bearing wall to be removed does not extend across the entire span of 240cm, but it extends about 100-110cm. The wall is framed with 5x 45*95mm studs (C14/C24), of which 3x 45*95mm studs are assembled as a "post" to take point loads of 26kN that come about 100cm into the span (I hope you understand what I mean).
The building is of modern architecture, with building elements in wood.
The floor structure consists of 22 particle board, 45 insulation, Beams 45x220 c600, furring 28x70 c300, 13 gypsum.
Exactly in line with where the wall is to be removed and supported, there are 2x 45x220 "beams" that are back to back. On these, there are then joist hangers c600 with 45x200 that support the floor/joist structure in two different directions.
Best regards
Richard
First, I want to say that I am a layman, not familiar with all the terms and have been Googling intensively recently to somehow verify the calculations I have received and also make them match the information I read on various forums and specs for materials (glulam beams in different dimensions). My feeling also tells me that the forces the engineer has calculated are still too small, but I don't know.
As an addition to my first description, I can say that the load-bearing wall to be removed does not extend across the entire span of 240cm, but it extends about 100-110cm. The wall is framed with 5x 45*95mm studs (C14/C24), of which 3x 45*95mm studs are assembled as a "post" to take point loads of 26kN that come about 100cm into the span (I hope you understand what I mean).
The building is of modern architecture, with building elements in wood.
The floor structure consists of 22 particle board, 45 insulation, Beams 45x220 c600, furring 28x70 c300, 13 gypsum.
Exactly in line with where the wall is to be removed and supported, there are 2x 45x220 "beams" that are back to back. On these, there are then joist hangers c600 with 45x200 that support the floor/joist structure in two different directions.
Best regards
Richard
You should probably contact the designer again and check to make sure he has all the conditions. As you describe, it seems to be a furnished upper floor above the beam. In such a case, the load is 2kN/m2 beyond the self-weight of the joist. 0.5kN/m2 (500N/m2) you mention corresponds more to the load used when dimensioning an attic joist "with limited access," or he may have only accounted for the self-weight of the joist, which usually lands at about 0.5kN/m2.
Thank you Bossesspecial
After further discussion with the designer, we have partially concluded that part of the point load most likely comes from the bjälklaget. We will remove more of the ceiling below to ensure we haven't missed anything. Update to follow
/R
After further discussion with the designer, we have partially concluded that part of the point load most likely comes from the bjälklaget. We will remove more of the ceiling below to ensure we haven't missed anything. Update to follow
/R
Click here to reply