Hi,

It would be really great if someone could give me some advice on the following issue:

Last year I bought a house and had a hardwood floor installed (solid hardwood, stapled on plywood over crawlspace). Since then, there has been some noticeable crackling of the floor, especially in the kitchen. It's gotten worse over the year and it's now almost impossible to step anywhere in the kitchen without getting a loud crackling sound.

The sound normally occurs when I release the weight from each spot. Surprisingly, I can't detect any movement of a particular floor board. From the top it looks like the boards join together perfectly, without even the slightest gap. Also, the crackling is not localized to a particular board, but to several regions, each having a diameter of about 2-3ft. I can step anywhere in each region to get the same effect. It seems like all boards move downward and upward together to produce the sound.

The other surprising thing is that the crackling intensifies throughout the day. In the morning, it is not very strong, but as more and more people step on it, it gets louder and louder. In addition, the crackling seems less severe if the air is humid or after wet-moping the floor.

One other thing that I should note is that the floor in the kitchen seems a bit "bouncy", meaning that if I walk on it, then I can hear the plates in the cabinets vibrating. Also it may be the case that the subfloor was slightly warped due to the weight of the counters. I'm not completely sure about this though, and I don't know if it is relevant here.

I complained about the crackling after the installation was completed, but the installers said that some general crackling throughout the house was normal and will eventually subside. As for the kitchen, they blamed the subfloor. However, when I looked at the subfloor from the crawl space, everything looked fine and there didn't seem to be any movement.

Has anyone had a similar experience? I would greatly appreciate any advice or any guesses on what the issue could be. Is there some simple way of fixing the noise or is it likely that the whole job has to be done again? If so, who would normally be responsible for it financially?

Here is some extra info on the floor:
* solid bamboo hardwood floor
* installed on plywood underlayment above a crawlspace
* boards are about 4" wide
* stapled about every 12"-14", some of the staples protrude the plywood and can be seen from crawlspace
* Prior to installation there seemed to be a mix between carpet, linoleum with an intermediate asbestos layer or tiling (in the kitchen)
* Two boards have developed a small crack in the middle, but there is less crackling directly near these boards.
* There is a little bit of crackling everywhere in the house. It is only noticeable if I rock and shift my weight a lot and is comparable to the noise created when stepping on a thin plastic film.

All the best,

Richard

From what you say about the fastening, staples 12-14 inches apart, its no wonder that you have enough movement to cause noise when the floor is walked upon. Bamboo flooring is one half or five-eighths of an inch thick. Flooring this thickness should be fastened closer together, usually every 6 inches with a fastener within 2 inches of the ends of the boards. You could check yourself to see how far apart the fasteners are if you have some small round magnets called Bucky Balls. The magnets will be attracted to the staples, so you may find where the fasteners are in each row of flooring, if you let them roll.
I doubt the framing would be a problem if it was up to code, where the sub-floor should be glued down and fastened every 12 inches in the middle part of the sheets and every 8 inches around the edge where it sits on the floor joists within 3/4 inch of the edge.
If the fastening of the flooring is the problem, then you would need to call the floor contractor.

Thanks. Yes, I determined the spacing using a magnetic stud finder. The far spacing also looked suspicious to me, because the manual called for nails every 6-8 inches. I was hoping that staples are stronger than nails so that they could space them further apart.

Is there anything that I can do about this at this point? Maybe screw the boards tight from the crawl space?

You can screw the flooring to the sub-floor from underneath. The best way would be to follow each flooring row and add extra fasteners as needed. Pre-drill through the sub-floor until you hit the flooring using a bit that will be a larger diameter than the screw shank. Then use a screw that does not erupt through the surface of the flooring. Since the flooring may be sanded in the future, use a screw that is about an eighth inch shy of the surface. Since the flooring is not a full 3/4 inch thick this will be problematic. Using a washer or a wide flathead screw so it will not bury itself into the sub-floor when it gets tight would be better than using the countersink type of sheet rock screws.
What a lot of work!