I’m adding 1/2 inch plywood to the present 5/8 inch plywood sub-floor to prepare the floor for installation of ceramic tiles. On the existing sub floor there is noticeable bounce in some places (when you purposely vary your weight on it).
Is there any standard test method to determine how much bounce a floor has? I’m thinking of something like, the number of bounces a hammer makes on the floor, or maybe some other totally different technique. Perhaps there is a measuring tool out there for this?
Thanks
Replies
Well, Bob, you already measured it "(when you purposely vary your weight on it)" and it is too soft for tile. Probably even after you add the 5/8".
Bob,
the key here is are you getting the bounce between the floor joists, or are the joists themselves to springy.
If the sheataing/subfloor is is deflecting to much between the joists, the you should add a layer of rated underlayment plywood. And a layer of cement board if you have room.
if it is the joists, then you are into a structural solution.
adding a beam mid-span is the simplest solution without more info.
Mr T
Do not try this at home!
I am an Experienced Professional!
Mr T,
What the heck is wrong with you?
Guy asks a serious question, and you come back with a serious answer!
Are you ill? Certainly not the sort of thing the forum has come to expect from you. Granted, it would take some doing to come up with something funny to say about floor deflection, but I was kind of counting on you.
Frankly, I'm disappointed.
skipj
Lay the tile on the floor you got and keep your fatasss wife off of it!!!
Hows that??Mr T
Do not try this at home!
I am an Experienced Professional!
Stretch a string across the floor, and measure the distance in the middle of the floor with no weight on it. You may have to raise the string on each end the same amount to get it off the floor in the middle if the floor does not have any sag to begin with.
Then add a 300 lb. load in the center of the floor, and measure the amount of deflection. For ceramic tile, the deflection can be no more than L/360. For natural stone, the deflection can be no more than L/720.
By adding a layer of 1/2" exterior grade plywood, glued and screwed to the subfloor but not to the joists, 1/8" gap between sheets, it will add a remarkable amount of stiffness to the floor. A layer of CBU will not give the same amount of rigidity that plywood will.
Hope this helps. If you have further questions, go to http://www.johnbridge.com. The professionals there will help you through your project.
"Objects in mirror appear closer than they are."
Klakamp Construction, Findlay, Ohio