Heavy tiles concern

Discussion in 'Ceramic and Stone Q&A' started by Philomene, Oct 14, 2017.

  1. Philomene

    Philomene Member

    We are renovating a 20 years old house in Montreal,Quebec, Canada. We are installing 23-10/16””x23-10/16” porcelain tiles, 19lbs each on an open space area of 1200pi2. We used the sluchter system for heating floor, the orange mat just over the double layer plywood 1” total. My contractor is putting 1/2” of floor bond 8400 to level the floor, so this adds a 5lbs/sf to the tiles, total 10lbs/ft! I was checking to purchase a quartz countertop (10lbs/sf) and i was asked to check my floor joist. They are open joist in wood with steel web 10.5” height, 2.5” deep, space at 19.2” and span 11’10”. The guy who sell structure worries about the weight or the counter so that made me wonder if my structure can take the load of those heavy tiles! Nobody who sells the tiles or countertop seems to be concern about anybody structure. They said that they install those in very old place without any problems. I would like to have your opinion about that.
     
  2. Mike Antonetti

    Mike Antonetti I Support TFP Senior Member

    That is determined by a structural engineer. Not sure about leveler, hope it's designed and Schluter ok's it, hopefully it's a Gypsum product?
     
  3. Philomene

    Philomene Member

    Yes i know it would be safer to check with an engineer (not to easy to find for residential) but i am just wondering if my concern is justfy since we are taking about heavy tiles but still not as heavy as a ciment floor. For the floor bond, you think i should ask Schluter about that? We did the bathroom floor the same way and the wires are working fine.
     
  4. Mike Antonetti

    Mike Antonetti I Support TFP Senior Member

    Yes, it's definitely a concern, and also I've heard about heavy islands causing failures.

    The Floorbond 8400 is just a mortar? by Mapei? Yeah, I'd put my car in reverse.
     
  5. Philomene

    Philomene Member

    Thanks, just talk to a structural engineer who says that i would be fine since the span is less than 14.5 ft where the quartz will be! I have other rooms that are 15’ span so those would be a problem if i put heavy furniture.
     
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  6. Mike Antonetti

    Mike Antonetti I Support TFP Senior Member

    Tiling around island?
     
  7. Philomene

    Philomene Member

    No tiling was done before and since it is 24x24 it was better to do it like that
     
  8. Kman

    Kman Tile Expert I Support TFP Senior Member Published

    Those heavy islands can definitely cause a problem over time. It's not as if you set the island in place and see cracking in the floor within days or even weeks. But over time the stress on the joists could cause them to sag, which is definitely a problem.

    I hate to see floor joists on anything but 16" centers. The strength you lose can make all the difference in the world, and the savings is minimal.

    I would try to find the joist manufacturer and get their thoughts on your plans. Often there is a tag or stamp somewhere on the joists with manufacturer info.

    You don't mention what's below that floor, but is there any chance you could build some support underneath the area where the island will be? That would solve your problem, most likely.
     
  9. Kman

    Kman Tile Expert I Support TFP Senior Member Published

    Ok, I read up a little on the Floor Bond 8400 since I haven't heard of it before. I would not be using it the way your installer has, i.e. as a leveling product. Could a person fill a small area with 1/4" or less material? Maybe so. But I would never pour 1/2" thick bed of a product that is designed as a thin bed mortar.

    Thin-bed mortars have minimum and maximum thicknesses, and while I don't see one mentioned on the technical data sheet for that product, I would never use a trowel with a notch larger than 1/2" for setting tile unless the manufacturer allows it. Keep in mind that 1/2" notch trowel will compress as the tile is set, such that the bed will come out to 1/4" or less. In your case, you have a full 1/2" of thinset mortar with no compression. The usual outcomes of using a product in that application are shrinkage and cracking of the material, and often de-bonding.

    You should really look into using a proper leveling compound to level the floor. Some of those even require the addition of aggregate when exceeding certain thicknesses to increase strength and reduce shrinkage.
     
  10. Philomene

    Philomene Member

    Thanks for those advices, the guy i hired has more than 25 years experience, this is really stange... half the job is done, how can I tell if the tile will be debonding? After years, or can I find out now? He will not like that I tell him how to do his job, wow what a nightmare! For the truss, I have calculate L/1155 which is OK for stone floor, since I guess with all that mortar and the 5lbs porcelaine, I need L/720. My floor structure is floor truss (open work joist with steel web) so no support can be done to change the span. Below is the basement but filled with ventilation, etc... I will probably go for a very thin counter top that will weight 10lbs/sf just to be safe!
     
  11. Kman

    Kman Tile Expert I Support TFP Senior Member Published

    Loose tile show up in the form of cracking tile and/or grout. Those will be obvious.

    They will also sound differently when stepped on, or tapped with a hard object like a screwdriver.
     
  12. Philomene

    Philomene Member

    You are right, some tiles (not all) has pocket of air on the edge. I will talk to him for the second half. We are so tight in our schedule can we do anything to fill the pocket of air by using a product without removing what was done? I google and saw something call fix a floor, not sure if it is available in Montréal.
     
  13. Kman

    Kman Tile Expert I Support TFP Senior Member Published

    I doubt those products will work in your case. They are made for loose tile that have been grouted. The material is pretty thin, and flows to the area needed through the path of least resistance. If you use it on tile that isn't grouted, it'll just fill the grout joints.

    Have him remove and replace the tile that aren't properly bonded. That's what you paid for.
     
  14. Mark Brown

    Mark Brown On The Surface Flooring I Support TFP

    This sounds like it just got ugly. Every time i lay tile.... every time, the day i get back on them terrifies me. That hollow tile sound is my fear.
     
  15. Mike Antonetti

    Mike Antonetti I Support TFP Senior Member

    I will tell you Mark Brown, but only you! With thinset, two priorities are to ensure moisture is not robbed from thinset either from slab or tile by dampening slab without standing water with sponge, then by placing tile into just troweled thinset and rocking tile back and forth to embed tile locking thinset into tile body.

    25 years experience means nothing to me if Contractor is not up to date, attends seminars, is a member of trade organizations,etc. Otherwise, they’re just going through the motions.
     
  16. Jim McClain

    Jim McClain Owner/Founder Administrator

    Sometimes 25-years of experience only means 25-years of making the same mistakes over and over.
     
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  17. Philomene

    Philomene Member

    You were right the tiler was not good. He might have been in the past but he is just alcoholic who was trying to steel money by charging extra for cement. We check with a laser and he did not need to raise the floor that much. He ask me for more money and when we told no, he just left with 70% paid in advance. The job is unfinished but left me with a big mess. I trying to remove some tiles that are close to my staircase with 1" of thinset underneath. He raised my floor 1" at this place when the floor did not need to be raised. I can't remove all the floor but I would like your advice about 2 things

    1-How can I remove easily the cement without damaging the wire (I have schluter and wire) we were able to remove the tile easily but the cement is so hard ( he used Chembond 8400). I want to remove a couple of tiles to lower the floor close to the staircase

    2-Did you ever see someone installing a floor with a so thick cement base? He had done around 900 ft2 with a 1/2-1" cement underneath, I am not sleeping well, this is a nightmare! Can anyone tell me what to do? This was the last thing to do for my renovation that started in 2014! I spent so much in that floor with the schluter etc. This floor weighs 5lbs without the cement!
     
  18. Kman

    Kman Tile Expert I Support TFP Senior Member Published

    I doubt he was making much extra by using more mortar. The time and effort taken to mix it wouldn't be worth it, unless he's charging you double. Even then, it's much more difficult to set tile over 1" of mortar, since it would shrink excessively and cause the tile to sag, resulting in high corners.

    I have doubts you'll get the mortar up without damaging the wire, unless it was mixed dry and simple didn't bond well. Start small and work your way up to something heavy to bust up the mortar, and don't use anything pointed or sharp.

    Maybe if you're lucky he did a crap job of spreading it as well. ;)
     
  19. Philomene

    Philomene Member

    I am thinking just shaving 3/4".
    and leave 1/4". My goal is to lower it 1/2", i guess I can't really remove enough tiles to lower the tile more than that.....unless I find a magic trick. I have 2 weeks part time before the new tiler comes. I can see very well where the orange membrane is since it is the last tile he put. Is it ok to install the new tile on 1/4" base?
     
  20. Jim McClain

    Jim McClain Owner/Founder Administrator

    That would be a personal attack against someone who can't defend themselves. There is no way for you to prove either of those accusations online. It doesn't make you look good. Don't do that again.
     
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