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Flooring and Carpeting/mosaic tile installation, grouting - does my contractor know what he's doing?


QUESTION: Our contractor installed a 1-inch square border filled with 1-inch hex tiles in our kitchen. The tiles are unglazed black and white porcelain Daltile. After the floor was grouted last week, we noticed numerous issues: crooked tiles, edge tiles that fit poorly, grout that is too low, rubber pieces from the tile mats sticking up through the grout, uneven heights of tile, etc.

When we brought our concerns to his attention, he assured us that grouting is a process, and that it is standard practice to replace a certain percentage of the tiles at this stage. He also said that applying more than one layer of grout is typical and that there's no issue with adding more grout. I've read that grout doesn't stick well to grout (it adheres to the sides of the tile) and that you need to remove existing grout to 2/3 the thickness of the tile for best results. When I mentioned this, he told me the opposite is true, that grout adheres well to grout.

Nothing about his method lines up with what I'm reading about installation, so I'm curious if there are different schools of thought on how to install and grout mosaic tile or if we are being taken to the cleaners. Any guidance you can provide would be very helpful. Thank you!

ANSWER: Forgive my being tardy Margaret...had surgery on my ankle and been out of service.

  There is no method of covering grout by simply adding it overtop without creating "depth" to hold it. I don't care what any sub-contractor may say contrary to this statement. What I suspect is going on is there is a thickness issue where the 1" border is somewhat thinner than the field tile that it borders. You do not mention what the field tile actually is that it abuts but installing a hexagonal mosaic tile, a single row, means that the row was installed by hand into the adhesive and if the "dot mount" rubber is showing then perhaps they were installed one piece at a time. This would/could result in uneven tile placement, crooked installation and if the dots were trimmed off completely then there in nothing there to maintain the prescribed spacing and the fit could be off if not carefully monitored. If you look at the sheet of mosaic tiles the placement of the hexagonal pattern will not promote a single row of the tiles to be cut out in a straight row easily so typically they are just cut out individually and set by hand, so additional thinset adhesive will also be required to "build up" the thinner material to be flush with the thicker field material...perhaps a 12 x 12" or something like it. If the grout is low at this point of the install then removing grout in order to "fill" the joint properly is required not optional. Is the grout he used a "non-sanded" grout??...or did he use a "sanded" grout? I suspect he just used sanded for everything and this would make it more difficult to pack the joints of the smaller space with the mosaic with a sanded grout the material would be more easily washed out of the joint resulting in a low joint...simple stuff really. I do not know the level of experience for your contractor or if he had a helper do that part of the install but I am not impressed with the outcome for you. Ok Margaret I hope this helps you with your problem, feel free to return anytime...

Perry V.

---------- FOLLOW-UP ----------

QUESTION: Thanks for the response—hope your recovery is going well.

Our GC is doing the tile work, as it is supposedly his specialty (10+ years of experience). He does have a helper, and I'm not sure who did the initial grouting.

The tiles are all uniform thickness: the entire floor is 1-inch unglazed porcelain, square for the border and areas beyond, hex for the field—no individual rows of hex. The grout is sanded. Most of the tiles were laid as mats, and the variance comes from individual tiles that were replaced and not set at the same height. Where the hex tiles had to be cut to meet the border, things also got sloppy.

My main question is whether it's a standard practice to set tile and grout the floor, and THEN go back and remove/replace any unacceptable individual tiles. That seems unconventional, as opposed to trying to make sure the tiles are properly spaced and aligned before grouting.

I'm also wondering if we need to be concerned about how well the floor will hold up over time, given that the grouting was completed in two passes. We have no way of knowing how well they prepped the existing grout lines before applying the second layer. Is there anything we should look for that would indicate whether the job was done properly?

Hey Margaret welcome back...

   Your question about going back on an already installed floor as being a "conventional" method let me say this. When a floor is installed and then finished with grout the goal is always to correct any suspect tiles "as they are installed" not as a follow-up to a completed floor. Now it is possible that a few tiles that prove to be unacceptable to the customer may need to be addressed after things are installed and grouted as sometimes an install (if small) can be installed/completed one afternoon and then grouted the next morning before a critical inspection can happen. But if that is the case then it falls to the contractor to keep a critical eye on his or his helpers quality of work. Doing this as an afterthought is not a good business practice. You will always run the risk of having shading issues should tiles need to be replaced and regrouted. It's like running through an install as quickly as possible hoping that the customer won't notice or accept a less than quality installation just to get the money and run to the next one.
   It is impossible to predict how the grout will or won't stand up to the test of time. Visually the joints should be equal and even joint to joint, meaning the joints all need to be the same width row by row so there also shouldn't be a "fat, skinny, fat" look to the grout joint. You may notice small pieces of grout coming loose as the Seasonal changes come through, when in Winter when the heat comes on or Summer when the AC starts. It may even take more than one season to see anything happen. As you clean the floor just observe if the regrouted areas begin to break apart, it will be easy to see. Simply smearing more grout overtop of existing layer of grout has been and always will be a recipe for failure at some unknown date in the future. Ok Margaret I hope this helps you to move forward. Maybe you will be lucky and it last for a long time. Come again anytime...


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Perry Vellenga


Ceramic Tile/Marble. I can answer questions about floor preparation, tile selection, layout questions, performance of products, expectations of finish, compatabilities, questions about grout and epoxies, evaluating an installer, asking the right questions to check competence...more? 33 years this August 2012/ many years in commercial application from exterior finishes to Mall store fronts/ interior finishes like floor packages in stores inside Malls examples: The Limited, Lerner/NY, Lane Bryants, Bombay Co., Now involved in Residential new construction covering all types of interior finishes and designs.


I worked in an exclusive field of floorcovering called "Tenant Development" which is by invitational bid only, by way of a National bid list. These are large floor packages usually over 3500 sq. ft. of 18" x 18" Marble and Granite and many other types of Marble and sizes. They are specialty stores where the floor package can cost upwards of $50,000 for one store. I have also done "Structure" stores and J. Riggins stores, Lane Bryant,Express and Body Shop stores where wood flooring is used. Presently work for a National Flooring Company in the Residential new construction arena that covers most interior design elements..Granite Slab tops/wood flooring both job finished and prefinished ect..

My response's are published all across the Internet and picked up by multiple Interior Design sites and Industry related web sites where people have questions...

too many most of which don't count...

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