I am looking for assistance finding an non pigmented unsanded grout for Riad hand made concrete tiles. I installed the tiles without any problems according to the manufacturers instructions, sealed them with the recommended sealer and when grouting they stained. The manufacturer is vague about grout color, further research says non pigment and unsanded grout. Where could I find this and who would be the manufacturer of it? Please see attached information on the tiles. I have already removed the floor and am starting over as the tiles could not be cleaned to meet the customers satisfaction.
Grout as defined in ANSI A108.10 is a mixture of sand and cement in different ratios.
For on the job mixture:
• Grout joints up to 1/8” would be one part Portland cement to one part fine graded sand.
• Grout joints from 1/8” to 1/2” one part Portland cement ,two parts sand
In the tile manufacturers instructions it list exceptable grout manufacturers.
I spoke with those companies listed and two other technical support team they do not offer a non pigmented grout for joints under 1/8”. One company offer one for grout joints 1/8” or larger. Most explained that there grouts contain pigment in order to promote color consistency.
When using non pigmented grouts we are limited to the colors of cement available which are gray and white. The wide variety of grout colors offered by setting manufacturers is due to the addition of pigments to the grout. Concrete tiles are very porous in nature; as the tiles draw in moisture from the grout the pigment can be pulled in as well. Sealing and or saturating the tiles prior to grouting could elevate it this effect. If your grouting tile that has the potential to stain it is always good to test the grout on an uninstalled piece to see how it will react. Or create a mock up to experiment with different techniques to see what works best.
Always reach out to the manufacturer of the tile first. If you do not receive good answers proceed slowly and with caution.
In this installment, we look at these suggestions in more detail, some of them together, since they logically are part and parcel of the same process:
Understand the standards, and know the TCNA Handbook
Mark Heinlein, NTCA Training Director, Trainer/Presenter, and formerly a contractor in his own right, points to standards as the first line of defense, calling them the “alphabet soup of organizations and publications that guide our industry.”
The two to be most concerned with are: ANSI 137.1, the manufacturing standard for ceramic tile; and ANSI A108, the installation standard for ceramic tile that defines specifications for substrate flatness, maximum allowable lippage, grout joint size and other installation components, Heinlein said. And the TCNA Handbook contains the methods, details and best practices for installing ceramic and stone tile in dozens of applications.
Though these standards and methods are not law nor REQUIRED to be used, they are “highly regarded standards for tile industry materials and installations and hold up as such in courts of law,” he said. They work better when used in tandem.
“Here is my point: a certain tile may not meet some or all of the ANSI A137.1 specifications,” he said.“If it doesn’t meet certain specifications, it is going to be difficult for the installation contractor to meet the requirements of ANSI A108.” Heinlein observed that though these standards and specs are designed to help the contractor, many times they are unknown or ignored, much to the contractor’s peril if the installation is called into question.
Woody Sanders of D.W. Sanders Tile & Stone Contracting in Marietta, Ga., takes the standards seriously, engaging in ongoing study of industry documents and publications including A137, the TCNA
Handbook and the MIA Dimensional Stone Design manual. “Understand it is a voluntary standard, so educating your client to use an A137 tile is just like educating them on why they need to use qualified labor,” he said.
Don’t buy the tile yourself
Sanders also shared a strategy that works well for his company: “In our business model we work hard not to buy the tile or stone product. This is and will always be a hot topic but we do not have a showroom and our bidding strategies are different than others. We are a unique labor force whose focus is on tile and stone installation.We focus on billable service items, like delivery of tile. If a tile selected and furnished by others is out of spec or is not suitable, we work hard to find a resolution to our customer’s best interest, at the same time charging them for having to move the tile around or work on the resolution.”
Work with reputable distributors; order extra and do mockups
These two suggestions go hand-in-hand, along the lines of the proverb “Trust God and tie up your camel.” It’s great to trust that things will work out when you work with a reputable vendor, but it’s also wise to hedge your bets.
It is a no brainer to work with distributors you can trust. Even so, you may wish to inspect the tile when you pick it up. Sanders said, “I review lot numbers and calibers to see that they match or look at a few cases of stone if at all possible.” But he is clear that he is not the quality control on the manufacturer or distributor – and quality is THEIR job.
“That said, we work and have developed relationships with our vendors [so they understand] that we are not crying wolf,” he said. “We are looking for a quick and as painless resolution for all. But an uninstalled
tile is their problem. This is why we order extra and do mock ups in some cases on new tiles we have not seen before.”
Jeremy Waldorf, Legacy Floors in Howell, Mich., said, “It’s not truly possible, in my experience, to safeguard against substandard tile by going to the distributor and inspecting the tile in advance. The warehouses aren’t really set up like that, and even if they were there are way too many selections and not enough time. Often you can’t tell there’s something wrong until your layout runs off, you start seeing excessive lippage, or tiles start breaking funny while you’re cutting them.”
Bradford Denny, Nichols Tile & Terrazzo, Joelton, Tenn., added, “We greatly rely on our distributors to be looking out for the quality of the materials. If we can’t install it, they really can’t sell it. Additionally, it is a huge help when they educate the consumers in advance about the importance
of choosing tiles that meet
Stay ahead of the job; request technical information before starting a project when working with unfamiliar suppliers or owner-supplied material; and clarify that numbers for the project are based on it meeting standard
Staying ahead of the job means having everything you need at your disposal to launch into the project full speed ahead. As the subhead says, that means ensuring you have technical information on the project and materials and that the tile meets the standards for the application.
Sanders recommended troubleshooting in advance by having distributors send over tile cut sheets, SDS sheets, and manufacturers’ installation sheets during the bidding process – or getting them as soon as selections are made before ordering. “Look at them and look for problems,” he said. “Understand the tile types and their limitations.”
Denny added, “We try to circumvent this on the front end of a project. Working with reputable distributors can alleviate much of the problem, but when working with unfamiliar suppliers or installing owner-supplied material, we request all technical information in advance of starting a project, and any numbers given for the project are based upon it meeting the
Do not INSTALL substandard tile – and keep clients informed of the progress of the job
These two tips are also related. So you discover – on the job – that the tile you are working with is defective and is not going to fly. Now what? Is it something you can work around? Or do you need to order new material?
Contractors agree on letting clients know immediately if a problem arises. “As a general rule in every job I do, I am always diligent with keeping my clients informed throughout the entire process, whether good or bad,” Waldorf said. “I let them know the challenges I’m up against and how I plan to solve them. I also let them know when it’s an issue I can’t solve.”
Denny said, “Depending on the actual defective or unsatisfactory aspect of the material, we would outline the issues and discuss it with the client before proceeding, which could result in a new material being selected.”
Dave Karp, of Tile Fusion in Shakopee, Minn., said on some jobs where he has to deal with sizing or minor warping, he can open joints up more. “Worst case I’ll completely reject the tile,” he added, saying, “I also avoid certain distributors knowing there’s a high risk of [bad] tile.”
Be wary of homeowner-purchased product from big box stores
Though you may escape responsibility for bad product if you are not the one ordering it, if the homeowner orders the tile, other issues may arise.
“As a small two-man company, I run into some homeowners trying to ‘save a buck’ by going to big box stores when looking for tile samples,” said Phil Green, owner of P.G.C. Construction, Remodeling and
Design in Gilberts, Ill. “In many cases, the tiles that are purchased from these stores have their share of issues. The worst of these are the 2” x 2” mosaics on mesh backing. Sometimes the way they were shipped and stored, the sheets are deformed and tiles twisted on the sheet. We as the professionals are supposed to not only be the tile setter, but part magician as well.”
Problems Green has encountered aren’t limited only to mosaics – larger 12” x 24” tiles also have their share of problems. “Although I can understand that an ‘allowable’ warpage may exist in every large-format tile due to manufacturingBUT, out-of-square tiles and tiles that vary in size by 1/64” – 1/32” are very difficult to deal with.”
Educate the client to have reasonable expectations of what to expect from the job
This also applies to showroom personnel who often aren’t as knowledgeable about tile – and especially standards – as you’d hope.
Sanders had a recent experience with $15,000 of glass tile purchased for a steam shower. When he inquired about the thermal shock rating and whether the glass met ANSI, the tile distributor owner replied, “Can’t all glass tile be used in showers?” Clearly, it can’t, and the tile had to be reordered.
Sanders said, “We make an effort to be present with the designer and owner at the showroom or in early design meeting as much as possible to educate the owner as to the suitability of the tile and its intended use. Many times the showroom personnel do not know the standards.”
Waldorf explained, “I feel it’s extremely important to set reasonable expectations up front. I save a lot of headaches and problems by being honest and transparent with clients. ‘Under-promise and over-deliver’ is my motto. Like you and me, clients just want to know what’s happening with their home, and each challenge is an opportunity to build trust with them. This is why they hired a qualified professional, and sometimes you can be their hero just by delivering a quality service.”
Will following these tips make the substandard tile problem go away? Probably not, but they may reduce your liability and contribute to a smoother-running job and continued trust by your client.
The same way tile setters need to take responsibility for following installation standards and best practices when installing tile, tile manufacturers and distributors need to monitor their products to provide the best-quality products for contractors to work with.
“The tile manufacturers and distributors should have an active role in making sure the tile setter has an acceptable product that the end user will be happy with,” Waldorf said. “We should be working together as a team, and our end goal is complete satisfaction with the product and installation. If we don’t achieve that, another hard surface product will certainly take advantage of the opportunity. Many of us already fight a negative stigma about tile because of poor installations that consumers have had to live with. The manufacturing end of the trade needs to keep a reasonable pace and approach as we push the limits of size and speed.”
Templates, story poles help match the tile to the needs and flow of the space
By Ryan Willoughby, Hawthorne Tile
When you are deciding on a tile layout, it’s a good idea to check with ANSI 108.02 section 4.3 “Tile Layout, A General Statement.”
This document basically says we are to center and balance the area to be tiled, while both minimizing the amount of cuts and maximizing their size. Fundamentally these are the rules we follow, but in their definition and execution it can get quite subjective.
Having spent the vast majority of my career in the high-end residential market, some of my opinions may differ from someone in the commercial side of the business. That being said I feel pretty fortunate to have had a mentor who took extreme pride in layout and instilled the same in me. While maybe only other craftspeople and design professionals will truly appreciate all the thought and effort put into a great layout, I think everyone can feel the difference between a chopped up space and one that flows. If you don’t take the time to really think it through and begin with a clear vision of the finished project, you will make mistakes and have some uncomfortable conversations with your clients.
Besides being able to share my philosophies on layout, writing this article gave me an excuse to reach out and discuss the subject with someone I’ve watched on social media, the NTCA’s Oregon State Ambassador, Jason McDaniel. Jason has a really cool and unique approach to laying out some of his installs, but first I’ll walk you through my process and then share a bit from our conversation.
Getting started with tile layout – square, plumb and level
My first course of action is to familiarize or re-familiarize myself with any detailed drawings for the project and identify what the architect or designer’s vision for the space is. Next, I’d square up the space and locate any problem areas that will need to be discussed or fixed prior to install, such as an out-of-square room, or my wall tile tying into an out-of-plumb or level surface. Putting up perfectly plumb and level grids really accentuates these problems, and the smaller the tile, the more obvious it is. Someone may have a hard time seeing a 3/8” taper in a 24”x 24”, but it’s an entirely different story over the same distance with a 5/8” mosaic.
If you’re going to be tiling a shower to the ceiling, you need to know if the ceiling is 3/4” out of level across the back wall. On floors, I snap a reference line off my longest or most visual run and find square from that by using “3-4-5” also known – to the more academic among us – as Pythagorean theorem. To be honest, these days I just use a laser square; it speeds up the whole process. On walls it’s the same; find center, then plumb and level with either a spirit/bubble level or a laser.
Creating a story pole; envisioning the space
Next is creating a story pole. I’ll lay my tile on the floor with the appropriate joint spacing, and do one of three things:
Write the full tile measurements down, or
Measure off of the tiles on the ground, or
With mosaics, make a true story pole marking a piece of lumber at each joint.
Once I have all this information it’s envisioning the space and identifying the most visual areas. Do you want to “center” or “balance”? For floors: do I center the room itself, a threshold or hall, a kitchen island, a soaking tub, the shower, toilet? For walls: is it the space, a window, plumbing, start full here or there?
Our options are endless. Choose an approach to centering, and then work backwards from that first choice. You’ll also want to ask yourself, “If I don’t like the cuts I get in one place, what happens if I start somewhere else? What do I have control of?”
Niche sizes are typically nominal, as are height of the bench, pony wall, and curb. Looking at all of these things and being willing to do a little extra work will speak volumes to your clients and separate you from your competition. As Dirk Sullivan, Hawthorne Tile’s fearless leader, likes to say, “Never pass up an opportunity to do something awesome.”
The biggest mistake I see people making is getting locked into their first choice and not weighing all their options or passing on that opportunity to be awesome in lieu of saving 15 minutes. I’ve found making these suggestions to an architect or designer is typically welcome and appreciated.
The McDaniel solution: templates for elaborate installs
With the advancement of manufacturing technology we’ve seen all sorts of new shapes and patterned mosaic sheets become readily available. These more elaborate patterns can make it difficult to see what every cut will look like on a kitchen splash with multiple stopping points.
I saw Jason McDaniel of Stoneman Construction, LLC in Lake Oswego, Ore., making templates for these installs and thought it was a great idea. I gave him a call to talk to him about it.
Jason has a background in solid surfaces and was comfortable with making templates. The first time he tried it on a tile install was while working on a large project, a beautiful home where he had already completed four bathrooms. He came to a backsplash that had many things to consider: a window, cabinets, and multiple outlets. He was setting a 1” x 3” marble herringbone mosaic.
He looked over the space wondering where to start. That’s when it hit him – he made a quick template, laid the tile on the floor, was able to lay the template over the tile, and quickly see everything. He marked all his cuts, made his cuts, and had the backsplash set within a couple of hours. He saw in that moment that this was going to be something he’d be doing much more of in the future.
Jason shared with me other installs where this method really shines, like installing water-sensitive stones with epoxy or a rapid-setting thinset. You don’t have to stop to take a measurement or go to the saw – just comb and go. Or when stopping by a job on your way home, you can make a quick template, lay out the tile at your shop the next morning, make all your cuts, and hand them off to your installer. When I asked Jason if he had any advice, he said, “’Centered’ and ‘balanced’ are the terms most often heard when talking about layout. I lean more towards ‘balanced’ when laying out a space. Balanced doesn’t always equal centered, especially with all the different shapes and sizes of product we are seeing these days.” I couldn’t agree more.
Chicago’s iconic John Hancock building was put into service early in 1970, but 46 years later, one of the world’s highest indoor swimming pools drastically needed an update. Archimage Architects, Ltd. was awarded the project of a full remodel on the existing health club, including the pool and locker rooms. The space was gutted down to original concrete substrates, but until the demolition was complete, no one knew for sure what they’d find.
Clune Construction, the general contractor, awarded the tile contract to Trostrud Mosaic & Tile Co., Inc., early in the bidding process, due to the 10-week lead time needed for procuring the Italian porcelain tiles. This proved to be a fortuitous decision due to the on-the-job meetings with architects Kirk and Sheryl Stevens.
Trostrud was intent on setting a level-of expectation regarding the flow or puddling of water, at the barrier-free showers and the pool deck, insisting on a minimum 1/4” per foot pitch to drain to avoid pooling of water in the deck and locker rooms. The condo association balked, expecting the pool deck to drain just like a large shower floor. This conflict presented significant challenges, including a drainage drawing that was modified three times before getting agreement from all parties.
The existing pool was to receive a new stainless steel coping that would be set as high as possible to allow for the required pitch. At the perimeter of the pool deck Trostrud was required to meet existing aluminum flashing which could not be changed. The final drainage drawing consisted of several linear drains and many spot drains.
When the demo was complete and the tile mud beds were removed, it was clear that the existing concrete subfloor at the locker room required significant help. Leaking showers had caused rebar to rust and expand, fracturing areas in the sub floor. With the help of a structural engineer, the slab was rebuilt. All the adjustments resulted in a four-week delay in an already-aggressive schedule.
Once the floors in the locker rooms were resolved, the first phase went off without a hitch. The pool deck was another story. The pool contractor set his stainless steel coping 1/2” lower than agreed. Trostrud discovered the error when setting spot drains, in the beginning of the pool mud-bed installation. This greatly complicated the installation, and correcting the coping was not an option.
“We preceded the best we could,” said Brad Trostrud, vice president of Trostrud Mosaic & Tile Co., Inc. “Mike Miller, our foreman, worked his magic to make the deck drain effectively.”
The new schedule also required Trostrud to mud set over a freshly poured, uncured concrete slab. Even though Trostrud was using a floating mud bed, they worked with Tyler Barton from MAPEI and the concrete contractor to devise a better solution. It was determined that Barrier One Porosity Inhibiting Admixture, added to the mix, would allow Trostrud to cover the slab in 10 days.
The Italian porcelain tile was Caesar Uniqua in Tiburtina, Argentum and Imperium, and well as a solid black tile by Caesar. Glass mosaic was from Island Stone. Products were sourced through Virginia Tile in Wood Dale, Ill., and set using MAPEI products, including Ultracolor Plus, Keracolor U, Ultraflex LFT, AquaDefense, Adesilex P-10 and Mapecem Quickpatch.
When the job was completed, the condo board and Archimage Architects were extremely satisfied with the results.
The NTCA ReferenceManual is an important industry document that approaches challenges in the field from a problem/cause/cure format. It is free with NTCA membership or can be purchased at the NTCA store at www.tile-assn.com. The comprehensive culmination of knowledge, research, development and publication of the efforts of the NTCA Technical Committee addresses many problems that arise in the field, how to prevent them or address them when they occur.
Today we look at the chapter on Large Porcelain and Glass Bondied Tiles, appearing in Chapter 6, page 124 in the 2016-2017 version.
Loss of bond between bond coat and large porcelain tiles or tiles containing high percentage of glass in the body. Tiles may come off mortar bond coat clean,even with full coverage on backs of tiles.
Any of the following may prevent problems with large porcelain and glass-bodied tiles.
Inadequate contact between mortar bond coat and backs of tiles which may be caused by improper beat-in and using inadequate amounts of mortar, or worn or improper trowels.
Use of pure cement bond coat over plastic mortar beds.
Use of dry-set mortar without latex additives.
Presence of excessive white powder (manufacturer’srelease agent) on back of tile.
Bending or deflection of substrates.
Differential expansion between tile and setting material.
Working on or too early traffic on newly laid tile floors.
Shrinkage or setting of substrates due to changes of moisture in structure or movements in the structure after construction is complete.
Improperly engineered structure for the installation put into place.
Any of the following may be a cure to problems with large porcelain and glass-bodied tiles.
To secure good contact between tiles and ribs of latex-Portland cement mortar, tiles must be pushed and slid into the mortar using NTCA recommendations for bedding tiles. Backbuttering tiles with a thin, flat coat of latex-Portland cement mortar helps develop a better bond to the tile.
On large format tile, a box screed has proven to be an excellent means of controlling the amount of mortar applied to the back side of large tiles. Latex-Portland cement mortar applied to the substrate should be troweled out evenly in one direction – not swirled – with notched trowels. Ribbed mortar on only one surface helps reduce voids and air pockets. This method also produces a smoother, more even surface than conventional backbuttering, which often leaves tiles with excessive lippage.
Successful installations of large porcelain and glass bodied tiles require the use of a manufacturer’s recommended latex-Portland cement mortar which meets or exceeds ANSI specifications. Use latex-Portland cement mortars that are more flexible, in addition to having superior bonding capability. Latex-Portland cement mortars bond large porcelain tiles and tiles containing glass in the body, better than more conventional mortars. Mortar fl exibility helps bridge stresses created between substrates and large, unforgiving tiles, reducing possibility of tiles shearing off. Check with manufacturer for exact products recommended.
Press or slide tiles into position using NTCA recommendations for bedding tiles. Check to see that uniform contact is being achieved at corners, edges, and the back of the tiles by pulling tile up for examination. Beating-in only of larger tiles generally is not effective. Average contact area shall not be less than 80% except on exterior or wet area installations (see TCNA Handbook for wet area definition) where contact area shall be 95% when not less than three tiles or tile assemblies are removed for inspection.
Check tiles for presence of excessive white powder (manufacturer’s release agent) on back of tile. If necessary, brush or remove white powder before attempting to bond tile.
Porcelain tiles have extremely low water absorption rates. As a result, the setting time of many latex-Portland cement mortars may be extended. Therefore, working on or exposing the installation to traffic prior to a good bond forming may result in poor performance of the completed job.
Proceed with caution when installing large porcelain tiles over substrates subject to bending or deflection. When installing materials with special or unique properties, the code minimum may not be sufficient to provide satisfactory performance. Each project presents its own conditions; consult with owner or builder to determine if any modifications to the structure can be done prior to the installation when you suspect problems or have concerns.
Web floor trusses and engineered I-joists are used in ways which weren’t possible with traditionally sawn lumber. Be aware of the conditions you face prior to installation so adjustments can be made if necessary. See NTCA’s document on Installations over Engineered Wood Products for additional information.
Require architect or construction manager to locate movement joints in tile work as recommended in the TCNAHandbook. Design, locations, spacing, and actual installation must conform with requirements in the TCNA Handbook and ANSI Standards. Movement joint recommendations apply to residential construction as well as commercial and industrial construction.
When faced with installation of large porcelain tiles or tiles with glass in the body, insist on using latex-modified Portland cement mortars when they are not specified. Also, require mortar manufacturers to furnish test results showing bonding and flexural capabilities of mortars and bondability of tiles from tile manufacturers.
FEELWOOD, from EgeSeramic is a satin-finished, glazed porcelain with a look of naturally aged and weathered wood. Vintage wood-look 8” x 48” plank tiles are available in three colors (white, grey and brown) floors and/or walls in residential and commercial settings. www.egeseramik.com
Fiandre recently introduced the U.S.-made West Loop, named for the emerging Chicago neighborhood and resembling textured industrial concrete. It features high color variance including 35 shading patterns, with metal undertones. In four colors in 24” x 48”, 24” x 24”, 12” x 24”, 8” x 48”, 12” x 12” mosaic and 4” x 12” diamond.www.granitifiandre.com
PreciousHDP from Florida Tile authentically captures the essence and beauty of Calacatta marble, including the stone’sintense and random grey and brown veins that stand out from a crystalline white background, endowing it with a depth and movement that enlivens spaces. Rectified, porcelain floor tiles in a natural finish are available in 12” x 24”, 24” x 24” and 18” x 36”, with rectified ceramic wall tiles in a polished finish, two mosaic offerings, a ceramic wall deco and full package of trims. PreciousHDP ismade in the USA of 40% pre-consumer recycled content, is GREENGUARD® and Porcelain Tile certified. www.floridatile.com
Crossville has created a sophisticated, clean concrete look in the porcelain stone Notorious, in the same six colors as the wood-grained plank Nest. Modular sizes include 3” x 15”, 12” x 12”, 12” x 12” mosaic parquet, 12” x 24”, in unpolished and 24” x 24” and 24” x 36” in unpolished/honed. The package includes cove base and bullnose, perfect for healthcare and restaurant applications. Notorious is made in the USA with recycled content and is Green Squared Certified®. www.crossvilleinc.com
Many contractors contact NTCA technical advisers regarding acceptable tolerances for floor tile installations, but our trainers also tell us that with the increased use of large format tile being specified for walls, it is becoming increasingly challenging for tile contractors to successfully install these products without lippage. Contractors should be aware that the tolerances for both floors and walls are the same, and that this issue should be addressed before installing the tile. Many applications in dry areas are to be installed directly over gypsum board or drywall, and there is little opportunity with the adhesive to make up for imperfections in the surface. Lighting can also wreak havoc on a tile installation on a wall, making the edges appear to be even more uneven and imperfect. Industry tolerances for both floor and wall tile applications state that the substrate should have a maximum variation of /14” in 10’ from the required plane, nor more than 1/16” in 12” when measured from the high points in the surface. If a builder wants a tile installation to be flush with no or minimal lippage, they need to make sure the framing and drywall contractors are delivering a surface that meets tile industry tolerances. If the tile contractor doesn’t check for this, and accepts the substrate as is, they run the risk of having a serious issue take place that can cost everyone money and time.
For more information on this subject, you can order the TCNA Handbook or ANSI A108 Book for tile installation on the NTCA website at www.tile-assn.com
Q: Are there any standards or situations where it is acceptable to install ceramic tile over gypsum wall board and not a tile backerboard?
A: There are two methods in the Tile Council of North America handbook for installation of tile over gypsum board. Method W242 which employs organic adhesive for a setting material. And Method W243 which employs the use of thinset mortars that meet ANSI 118.1 or 118.4 or better.
In W242 (organic adhesive method) in the section preparation by other trades it states ” The maximum allowable variation in the tile substrate is 1/16 of an inch in 3′ with no abrupt irregularities greater than 1/32″. Both methods specify the gypsum board is to be installed according to GA216. ” Treated with tape and joint compound with bedding tape only( no finish coat) Nail heads, receive only one coat.
In Method W243 (thinset method) it states ” Maximum allowable variation in tile substrate for tile with edges shorter than 15″ the maximum allowable variations is 1/4″ in 10′ from required plane with no more than 1/16″ variations in 12″ when measured from the high point of the surface. For tiles with at least one edge 15″ in length, maximum allowable variation is 1/8″ in 10′ from the required plane, with no more than 1/16″ variation in 24″.
So there are many standards depending on the type of tile and adhesive you are using.
Proper preparation of substrate to ensure flatness requirements and installation of tile with acceptable lippage are key components for a successful wash wall lighting installation. Determination of grout joint size and layout and location of lighting prior to the installation are critical. Creating a mockup with lighting placed as it will be in the final installation and having all responsible parties review the mockup, make adjustments, or sign acceptance is strongly advised before proceeding with such an installation. NTCA Reference Manual Chapter 6, pages 113 – 120 provide an excellent discussion on Critical Lighting Effects on Tile Installations. Page 114 lists a series of 12 recommended tips for the tile contractor to prevent issues resulting from lighting
Dan Marvin, Director, Technical Services, MAPEI Americas
Membranes that are applied wet and allowed to dry are everywhere in the tile world for waterproofing, crack isolation and more. But how do you know if you need one coat or two, or more? There are lots of rules of thumb – ‘If you can see through it you need another coat’ is a common one – but the only true way of knowing for sure is to measure it.
To determine if you have applied enough liquid membrane, you need to know how much the manufacturer recommends. Almost all technical data sheets for liquid-applied membranes list a target film thickness. It will typically be listed in the form of “mils” of thickness; each mil is one one-thousandth of an inch (1/1000” or 0.001”). So, a 30 mil wet film thickness (you will often see this abbreviated WFT) means 0.030” of membrane. You will also see dry film thickness (DFT) referenced. To determine the dry film thickness, multiply the wet film thickness by the percentage of solids in the product (30 mils of a 50% solids membrane is .030” x 0.5 = 0.015” DFT).
As manufacturers, when we measure the properties of these membranes, we assume that you are using the correct amount. If we tell you that water will not penetrate the membrane, we mean water will not penetrate the specified thickness of the membrane. If it is extremely thin in some areas, or has holes in it from nails or pinholes during application, it will not be waterproof. Likewise, if we say that a crack isolation membrane can protect your floor from a 1/4” substrate crack, the size of crack the membrane protects against goes down as the thickness of the membrane goes down.
This is particularly important in steam showers. The thicker the membrane, the more it resists high temperature/high pressure water from moving through it (the ‘permeance’ of the product). The TCNA Handbook for Ceramic, Glass and Stone Tile Installation requires no more than 0.5 perms from a membrane being used in a steam shower. The liquid products that meet this requirement typically do so at 30 mils or more, much thicker than you would apply with one or sometimes even two coats. If the steam shower fails – and you did not apply enough waterproof membrane – that is on you.
Luckily, measuring wet film thickness is very straightforward. There are a variety of gauges available to manually measure the thickness, so make sure that you are using one that measures in the range you need. Sometimes you will hear them referred to as ‘combs’ or ‘rakes’ because of their shape with numbered teeth that show the film thickness.
We are including such a MAPEI wet film thickness gauge in select TileLetter issues. If you did not get one, contact your MAPEI sales rep.
Once you have applied your wet membrane (and while it is still liquid), place the wet film thickness gauge straight down into the membrane. Do not wiggle or move the gauge, just make sure that it goes all the way to touch the substrate. Remove the gauge and begin looking at the bottom of the teeth. Teeth that are longer than the membrane is thick will have membrane on them. At some point, you will find a tooth that has no membrane on it. The thickness is between the number on that tooth and the one next to it that has membrane on it. That’s it! Try it in several places to make sure you are seeing consistent results and wipe off your gauge quickly after every test – you do not want buildup on the teeth.
Once you have performed the test a few times, it becomes a quick double-check to ensure you are getting enough membrane applied. It can also show if you are applying too much.
If you ever need help determining the required thickness of a MAPEI membrane or have questions about the process, feel free to call 1-800-992-6273 to speak with a Product Support Representative.
Mold is a destructive organism that can overtake grout, stone and tile in showers and wet areas, rendering them not simply unsightly, but also unhygienic.
Sometimes mold is superficial and resides only on the surface of the installation. Most shampoos and soaps contain organic matter, some more than others. When you have organic materials, warm temperatures and moisture, you have a great environment for mold to grow.
Proper and regular cleaning of showers removes those materials. When used and not cleaned regularly you can end up with discoloration on grouts, stone and tile. Always use neutral pH cleaners approved for cleaning the stone or tile in your shower. And always test the cleaner in a inconspicuous area to make sure there’s no adverse reactions.
Double check for mold or wet areas outside the shower as well to ensure there are no leaks. If water has escaped the shower assembly and has reached the wood substructure this can also provide the organic matter needed for mold to grow.