Tile over floor trusses - Ceramic Tile Advice Forums

tallycat77 · 04-12-2005, 01:12 PM

I have been trying to research a bathroom project and was recommended to check out this fourm. I have a 1986 wood frame townhome, built off grade with 2x12 floor trusses, 24"OC. I want to be clear about the trusses, they are 2 2x4's connected with metal bridging that sit 12" apart vertically. Different advice from different folks has left me at somewhat of a loss. I need to replace a patch of the bathroom subfloor between the tub and the toilet and would like to cover with 1/2" hardiboard and then tile. Some have said this is no problem, others have said no can do. If tile won't work, I can go with linoleum or laminate, but still need some advice on making the patch. The hole sits in between two joists - one is on the bathroom side and the other is on the kitchen side. How do I support the patch? I was thinking blocking, but was again warned that a floor truss system is very technical and that I shouldn't make any changes. If anyone can offer advice, I appreciate it. Until then I have a small rotten hole from an old water leak. The joists do not appear to be affected but this is challenging since the other joist is on the other side of the wall. Thanks in advance.

jdm · 04-12-2005, 01:22 PM

Tally --

Can you go down under the house and get any names and numbers from the trusses. The engineers need to know exactly what they are before they can say their sooth.

Mike2 · 04-12-2005, 09:14 PM

Hi Tally - that your first name?

How to patch that "hole" really depends upon how big it is. Be advised that for joists spaced 24" OC you will need a double layer plywood floor, 1 1/8" total thickness (I'm assuming you intend to use ceramic tile, not natural stone). If the hole in the first layer is "small" it could be blocked with a larger piece of plywood glued and screwed from below. But again, we need to know how big it is.

Additionally your truss joists need to be checked to determine if they meet L/360 deflection requirements for ceramic tile.

abnorm · 04-14-2005, 04:55 PM

Call me Doug.......I directed "tally" over here from the BobVila Forum for your expert opinions.......

She owns a small two story townhouse with first level flooring problems.......

From her e-mail descriptions she has something like these engineered trusses:

http://www.spacejoist.com/page1.htm

On 24" centers.......With a single layer 1 " plywood floor..........

Of course she would like to tile.........existing vinyl flooring.........

........the bathroom floor is water damaged ..........

a non-bearing kitchen/bath partition wall is located between two trusses.......the kitchen floor shows some signs of previous "repairs".........

she originally asked about supporting the wall and removing everything to the trusses and rebuilding the floor..........I said WAIT........

She's all yours....and thanks.........doug

Tally?....you're next..........

rich7 · 04-14-2005, 05:15 PM

Tally...what Mike said about the deflection is true..you need to give us a couple of more facts...the span..the distance between walls, or beams that support the trusses and the manufacturer data..the link Doug put up for spacejoists is the type of chart we will need to figure out what the trusses will bear..if, in fact, you do have that brand truss, then you might be ok for ceramic tile...no stone, no way...also, did you mean you have a partition wall between the trusses?? and that is where the hole is??..I read it that way...if that's the case, a few strongbacks (blocking) between trusses will take care of the wall..I'm trying to interpret both yours and Dougs posts..tell me if I'm even close..

....

tallycat77 · 04-15-2005, 11:49 AM

Quote:

Originally Posted by jdm

Tally --

Can you go down under the house and get any names and numbers from the trusses. The engineers need to know exactly what they are before they can say their sooth.

Where do I find the numbers? They are 16' long, 24"OC, 12" high. Subfloor is plywood between 1" and 1 1/8" thick.

tallycat77 · 04-15-2005, 11:55 AM

Yes, there is a partition wall that sits in between trusses (runs parallel to them) However, the hole is in the floor between the tub and the toilet, approximately 8" wide, but there is additional rot around this area. Probably 1 sq ft total. The final floor is really the least of my concerns at this point, tile is of course my preference, but if that is not possible, I can do some lino. Can I just cut the bad part out and patch? The only reason I have not done this yet is the position of the hole between the trusses and even though there is only about 4" on that side of the wall, I don't know how to support the floor on that end.

John Bridge · 04-15-2005, 03:04 PM

Hi Tally,

Cut out the one foot square or whatever and then screw two by fours flat up against the undersides of the surrounding floor. Let them hang out so that you can screw a new patch down onto them. You need a power screwdriver/drill for this. You can simply hold the blocks and screw through the plywood into them and draw them up tight. Don't screw into your fingers.