Stabilizing Your Wood Floors
LESLIE: Woody in Ohio is dealing with a bouncy floor. What’s going on?
WOODY: Well, when I walk in the dining room my China cabinet begins to rattle somewhat and I’m kind of curious how could I stabilize my floor joists without having to go and replace the joists or my wiring going through and what have you.
TOM: Not really. Woody, how old is your house?
WOODY: God, about 86 years old.
TOM: Ah, it’s a pretty old house, yeah. Well, in an older home, typically the spans on the floor joists are a lot longer and the joists themselves are narrower than what you would have today. And so, what I would do in this case is I would suggest you put in a midspan girder and this does not have to be really complicated because we’re not really holding up the house here. We’re really just sort of taking the flex out of that floor. So what you would do is you would go downstairs – is this on a basement?
TOM: OK, so you would go downstairs to the basement and you would install a beam that would be comprised of maybe three 2x8s, ought to do it. Midspan between the two ends of the joists that cover the dining room area; right down the middle, make sure you have good contact to all the floor joists – and because it’s an old house you may do a little shimming here and there to make sure you have good contact – and I would support that beam with probably two or three lolly columns. Now, you could probably put it right on the concrete floor because, again, we don’t necessarily want to do anything more than take the flex out of this. If you want to do a real super good job you could dig out the floor and pour a little footing there; maybe something that’s about 18 inches deep by about 18 inches square. But at least to start with I would just put a beam in the middle of the span of these dining room floor joists and that will take the flex out of it and you won’t hear the China rattle the next time you walk across the room.
LESLIE: Now when you’re assembling this, Tom, would you do sort of a staggered situation with a 2×4 so that it can become like one, long, continuous piece? You know, so like maybe the two end ones are even with each other and the middle one staggers out half of the distance so that you have areas to constantly attach things to; almost like a LEGO.
TOM: Not 2x4s. You mean 2x8s.
LESLIE: Oh, 2x8s. I’m sorry.
TOM: I would use as few seams as possible and the rule of thumb whenever you construct a load-bearing beam like that is if you have a joint in the beam – like if you had a triple beam with three, say, 2x8s and there was a seam somewhere – that seam would always be over a post.
TOM: You don’t have to be quite as strict about this because, again, we’re not really holding up much of the house; we’re just taking the flex out of the floor. But putting a midspan girder in there will solve this problem.
WOODY: OK, so it should be just the length of the dining room area in itself? Would that be it?
TOM: Yep. And across – perpendicular to the floor joists that are there right now.
WOODY: OK, 2x8s and three of them.
WOODY: What method would you use to fasten the 2x8s together? Would it be glue and screws or what?
TOM: No, I would just nail them together.
WOODY: Alright, then. Thank you so much.
TOM: You’re welcome, Woody. Thanks so much for calling us at 888-MONEY-PIT.