I expanded the house three years ago, and everything went well, and I am satisfied with my work except for the floor. The floor is not solid; it shakes a little when someone runs. I built with 220x45 beams 60 cc, then chipboard on top and parquet flooring. And it's a room 4 m wide and 7.5 m long, no support underneath, the extension is on a crawl space. So building central support is too complicated because it’s 7.5 m long, and if you place posts in the middle of the crawl space, I thought that if the ground shifts, it could sink or raise the central support, making the floor not completely flat and even, which I'd like to avoid. So, how do you think I should proceed? Tear out the old beams and replace them. Install the same 220x45 but at 30 cc, or is it better with glulam beams? How far cc is sufficient with glulam beams if I use 225x45 glulam beams? Or what ideas do you have?
I would also like to mention that I am thinking of buying a stove for the room if that matters for what I should do.
Especially in the past, it was common to use cross-bracing (I believe it's called that) to increase stability.
These are relatively thin studs mounted diagonally between the beams. That is, one is mounted on the upper edge of one beam diagonally down to the lower edge of the next beam, and another one the opposite way.
Support beam/bar in the middle... And some adjustable props holding up the support... standing on something solid..? Just brainstorming a bit... (That is, if you can get into the crawl space and there's room)
...feels sad if you have to tear up the floor again when it's almost brand new!
But I understand you, I have the same problem here...going to tear up the kitchen floor here in the near future... (The fridges attack when you walk by)
Cross-bracing can probably provide at least as good an effect as switching to glulam. And it might be possible to solve it from below without tearing up the floor.
IF you switch to glulam or cc30, it might still be right to cross-brace as well.
I have no way to enter the crawl space. And the floor has already sunk a little in the middle, so I was planning to remove the beams and put new ones in. But if I'm going to put in a support beam with adjustable props, I still can't go into the crawl space to adjust. There's no way in.
Yes, it has sunk maybe about 1-2 cm. A cabinet about 2 m high that stands by the wall leans a little... That's why I was thinking if it would be better to replace the beams with glulam cc60. Is it okay like that without support beam or cross brace?
