Hello,
Span 4.4m, current joists 70x195mm. CC about 54cm. Wobbly floor. Will screw 20mm oak floor onto the joists. Previously had pine flooring, still wobbled.
Have got the lumber now. What's best, to glue and screw a 45x195 against the existing ones, or to put a 45x195 between the current beams and thus get closer CC?
Then I'm considering bracing/cross bridging. Any opinions?
Span 4.4m, current joists 70x195mm. CC about 54cm. Wobbly floor. Will screw 20mm oak floor onto the joists. Previously had pine flooring, still wobbled.
Have got the lumber now. What's best, to glue and screw a 45x195 against the existing ones, or to put a 45x195 between the current beams and thus get closer CC?
Then I'm considering bracing/cross bridging. Any opinions?
Member
· Västerbottens län
· 18 051 posts
Reducing cc = new beam between reduces the deflection in the oak floor.
Doubling or placing between makes no difference for the deflection of the joist.
The oak floor can partly replace noggings/do the same thing, i.e., stiffen the floor and distribute the load over multiple joists.
Protte
Doubling or placing between makes no difference for the deflection of the joist.
The oak floor can partly replace noggings/do the same thing, i.e., stiffen the floor and distribute the load over multiple joists.
Protte
Hi, if it doesn't have any significance for the floor's deflection, then how should one proceed? What happens is that everything in the adjacent room rattles if someone runs around in the living room.
If you go from 70mm width to 115mm width on the beams, there will be no difference?
If you go from 70mm width to 115mm width on the beams, there will be no difference?
both options work well but I would probably reduce cc first and screw in 2 regular kortlingar between each joist. This way, the subfloor will be less wobbly already when you build it up and it might be a bit easier to work on it then. Cross kortling is a lot of work and quite unnecessary in your case so try to avoid it!
There will obviously be less bounce in the floor structure if you widen the joists, but there are many other advantages to halving the cc instead. For example, you reduce the bounce in the oak floor, but you hardly achieve this by screwing on a joist instead.
Hello, grateful for the response. The oak floor is 20mm and according to the Manufacturer, there is a requirement for a maximum of cc60. And already today it is cc54. Maybe it should be both. The timber isn't exactly expensive. There will be sofas, tables set up, and one wants to be able to have 20 people without having to worry.
Member
· Västerbottens län
· 18 051 posts
Don't misunderstand us, the deflection in the floor joists will be "halved", no matter if you double or add one in between. However, the deflection in the actual oak floor will be less with halved cc.spaxx said:Hi, if it doesn't have any effect on the floor joists' deflection, how should one proceed then? What happens is that everything in the adjacent room rattles if someone runs around in the living room.
If one goes from 70mm width to 115mm width on the joists, there's no difference?
Protte
Have you seen what the beams that are there now look like? Often they undergo some deformation over time, such as warping, which makes it difficult to get a good result from screw-gluing onto a beam. It's much better to reduce the center-to-center distance with more beams. Buy laminated beams that are more dimensionally stable.
It has to do with the fact that wooden houses are light in their construction, so it's hard to avoid completely.spaxx said:
Plank flooring makes the floor flex more than if you have screwed and glued chipboard. If you have the possibility to raise the floor, it would improve if you screw and glue chipboard on which you lay the wooden floor.
A follow-up question that occurred to me. If it rattles in the next room, it could be that there is some give in the support beam in the house in some way. If it's not the same floor structure, the vibrations shouldn't propagate in that manner unless they have a weak connection point between them? It may be that the measures you take here have quite a small improvement for the next room unless you also reinforce that floor structure. Or redo the connection to that floor structure so that it becomes more isolated.