Our living room floor in our 1920s house is bouncy.
The room is 4.40 x 4.40 with about 60 cm center-to-center spacing and approximately 220mm beams.
There is a basement underneath the living room.
I am considering installing a HEA 120 beam in the basement ceiling directly across the floor to "stiffen it up."
Questions:
1. Would a HEA 120 beam across with a span of 4.40 m make a difference, or do I need to increase the size of the HEA beam? I want to avoid losing ceiling height in the basement...
Can the beam be cast into the basement wall (which is made of cement / lime and large stones), or do I need to make a pillar against the wall to support the beam? It would be nice to keep that wall clean...
Thanks for the response!
Jonas
The room is 4.40 x 4.40 with about 60 cm center-to-center spacing and approximately 220mm beams.
There is a basement underneath the living room.
I am considering installing a HEA 120 beam in the basement ceiling directly across the floor to "stiffen it up."
Questions:
1. Would a HEA 120 beam across with a span of 4.40 m make a difference, or do I need to increase the size of the HEA beam? I want to avoid losing ceiling height in the basement...
Can the beam be cast into the basement wall (which is made of cement / lime and large stones), or do I need to make a pillar against the wall to support the beam? It would be nice to keep that wall clean...
Thanks for the response!
Jonas
One could do that, but HEA 120 sounds weak at 4.4 m. I haven't calculated it. There will be work with supports and foundations.
Is there a possibility to supplement with glulam beams or kerto in approximately the same dimension as the existing joists as an alternative solution?
Is there a possibility to supplement with glulam beams or kerto in approximately the same dimension as the existing joists as an alternative solution?
A HEA 180 is probably needed for that job. I agree with witten, it feels uncertain with that type of basement walls and unstable foundations. The "simplest" is to add extra beams between the existing ones. For example, glulam 90x225 mm. If a HEA 180 costs 4000 kr, maybe all the glulam costs 6000 kr.
An alternative that might work (depends a bit on how the existing joists look), is to glue and screw a 45x95 lying on the underside of each existing beam. The idea is that it will act as a tension flange. If you can also manage to block or cross-brace between the existing beams, it will be even better.
In the 1920s (and into the 1970s), the thumb measure was used for cross-sectional dimensions of timber. What width do your floor joists have? I would guess 50 or 75 mm.
Exactly, the beams are wider and slightly higher than 45X220. I don't have access to the exact measurements now. But they are substantial beams and good solid wood. There is actually nothing wrong with the load-bearing capacity in the room, but it would be nice to have a little more rigidity when the children jump from the coffee table onto the middle of the living room floor. Will I get more rigidity despite a smaller beam like HEA 120? Is there any risk that a too weak steel beam will be a bit "bouncy" or is it simply that the rigidity won't be as good with HEA 120 as with HEA 180? I also think that installation is faster and easier the smaller the beam you put in. Plus the preserved ceiling height. I'd be satisfied with noticeably less bounce but not perfect, while still retaining the ceiling height in the basement.
An HEA 120 will bend down terribly. There will be no rigidity with it. Overall, you have a problem attaching a beam to that type of masonry. Supporting the beam with columns assumes you know how the foundation is made, which may require breaking up parts of the basement floor. There are other alternative solutions besides additional joists, but there is no point in calculating them without knowing the exact measurement of your joists.
One option is to screw-glue two 25x230 mm (preferably, in urgent cases 23x220) boards on either side of your beams. This assumes that the old beams are fairly smooth and straight. This action will increase the beams' stiffness (moment of inertia) while the glue joints also contribute to greater resistance against deflection (better modulus of elasticity). The chipboard under the floorboards should also be glue-screwed.
A bit trickier to calculate because plywood has different properties than solid wood. It's probably fine to use, but I think solid wood is better. In this case, I would use 21 mm plywood.