What is purpose of crack isolation me...

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Author Message Jerome J. Lazar, RA, CCS, CSI, SCIP Senior Member Username: lazarcitec Post Number: 774 Registered: 05-2003 Posted on Wednesday, February 29, 2012 - 02:51 am:    and when do you include it in the specifications? Do you include it as a product in the installation of ceramic tile or do you provide a separate spec section? Dale Roberts CSI, CCPR, CTC, LEED Green Associate Senior Member Username: dale_roberts_csi Post Number: 90 Registered: 10-2005 Posted on Wednesday, February 29, 2012 - 09:34 am:    Anti-fracture membranes protect against horizontal cracks in the substrate from transferring up to the tile or stone. If you are concerned that you will have some movement in the substrate I would recommend its use. In the old days we had #15 roofing felt under 1 1/2” mortar bed (sand & cement) to protect from any movement in the substrate this is a very labor intensive, expensive installation. Not to mention that the floor was typically recessed to accommodate the mortar bed. It is typically included in the tile section. 2.2 MATERIALS Waterproofing/Crack Isolation Membrane: Where indicated on the drawings, and elsewhere as required for thin-set tile installations complying with ANSI 118.10 for waterproof membranes J. Peter Jordan (Unregistered Guest) Unregistered guest Posted on Wednesday, February 29, 2012 - 09:53 am:    This can be installed in strips over joints and cracks in concrete substrates so that you don't have to put an expansion joint right there. I think the width is 1-1/2 times the minimum tile dimension, but not less than 12 inches (please, someone correct me if I am wrong). This permits the "soft" joint in the tile to be offset from the crack/joint in the tile. This is recommended for thinset installations; not sure I want to use the No. 15 felt in a thinset application. Dale Roberts CSI, CCPR, CTC, LEED Green Associate Senior Member Username: dale_roberts_csi Post Number: 91 Registered: 10-2005 Posted on Wednesday, February 29, 2012 - 11:57 am:    You are correct #15 felt is not for a thinset application. Only for a thick bed or mortar bed installation. TCNA F125-Partial Crack Isolation Membrane, typically the membrane should extend 6” to 8” beyond the length of the crack in both directions and should extend beyond both sides of the crack and at least 3 times the dimension of the tile used. Remember you cannot move actual expansion or isolation joints, those should continue through the tilework. Check with the manufacturer regarding the relocation of saw cut joints I do not usually recommend the partial coverage. What if cracks develop after the installation? TCNA states Specifier to identify areas of coverage (partial or full). What if the contractor does not see any cracks to cover? On one installation the substrate was not within tolerance to install tile on (many cracks and the floor was not flat or level) So the GC hired a company to come in an self-level the entire area. Tile contractor saw no cracks and did not install an antifracture membranes (spec was to cover areas were cracks were visible). Job failed lots of cracks in tile ask why he did not install antifracture membrane he said at the time of installation there were no visible cracks (with pictures to prove it). You need to decide is there a possibility of movement in the substrate. Does the owner want an insurance policy to prevent cracking or is he willing to assume responsibility of seeing cracks in the floor and living with it or replacing it afterwards which creates its own challenges. Jerome J. Lazar, RA, CCS, CSI, SCIP Senior Member Username: lazarcitec Post Number: 776 Registered: 05-2003 Posted on Wednesday, February 29, 2012 - 12:16 pm:    So here is the problem we included Crack Isolation Membrane in the Tile/Stone spec sections, however the architect did not indicate extent on his drawings, so architect wants us to cover his butt by adding language to the specs - any suggestions - need language that is to the point and simple so even a GC will understand (no offense to GC members of this board). John McGrann Senior Member Username: jmcgrann Post Number: 84 Registered: 03-2002 Posted on Wednesday, February 29, 2012 - 12:43 pm:    Being an in-house specifier/architect type I get this kind of request all the time. Where the designer exhibits a reluctance to draw and prefers me to design with words, I've offered the following. Sometimes when they realize what I'm doing to their design they will change their minds and draw what they really want to see. Best, John. A. Expansion Joints: Locate expansion joints and other sealant-filled joints, including control, contraction, and isolation joints, where indicated, or if not indicated provide expansion joints at 24'-0" in each direction. Do not saw-cut joints after installing tiles 1. Provide vertical and horizontal expansion joints sized to match grout joint width, but not less than 1/4". 2. Where joints in slab do not correspond with joints in tile, cover slab joint with 12" wide strip of anti-fracture membrane centered over the joint prior to installation of tile. 3. See Section 079200 "Joint Sealants" for sealants to be used in expansion and control joints. Provide sealant color to match color of adjacent grout. John T. McGrann, Jr., AIA, CSI, CCS, LEED AP William C. Pegues, FCSI, CCS Senior Member Username: wpegues Post Number: 851 Registered: 10-2002 Posted on Wednesday, February 29, 2012 - 12:46 pm:    The following is how I do this, Jerome. I write a system description part 2 complete with products for each setting system. Below is a thin set system in a residential foyer. xxx is where I put my specific products from the manufacturers that i use. So I am telling them that its required. In this specific instance I am using a combined sound isolation/crack isolation material. If it was just crack isolation it would be under ALL floor tile everywhere. Note that some waterproofing materials can also be crack isolation membranes, but not necessarily vv. A. Floors, Thin Set: 1. Primers: Provide setting system manufacturer’s recommended primers for the system and products specified for all conditions recommended by the setting system manufacturer. 2. Self-Leveling Underlayment: Cementitious underlayment shall be required to be the same manufacturer as the setting system components. Underlayment may not be required where the floor flatness is achieved with the concrete or is acceptable to the tile manufacturer and the setting system manufacturer as required to comply with the respective warranties required. a. Refer to Section 03 54 00, CAST UNDERLAYMENTS. 3. Sound Isolation and Crack Isolation: Required under all floors over residential spaces. a. xxx. 4. Waterproofing Membrane: Required in all showers, all bathrooms including residential bathrooms, and all floors where there are floor drains installed. a. xxx 5. Bond Coat: a. Tiles 8 Inches or Less on Any Side: xxx b. Tiles Greater than 8 Inches on Any Side: xxx 6. Grout: Refer to Section 01 62 00, PRODUCT OPTIONS, for grout color and texture. a. Joints Less than 1/8 Inch: xxx b. Joints 1/8 Inch or Greater: xxx Rule of thumb, put down a crack isolation membrane everywhere on floors, do not attempt to address visible cracks separate, the installation of the crack isolation product, if its good, will address existing slab cracks on its own. I have been using crack isolation membranes for years, and for the many many tile installations we have done the only failures have been when 1 was not used, or where they used other non specified products. Even those have been very rare (2 projects, tile installer 'used his own ideas' and ignored the spec entirely). You will note information about underlayments implying single source materials. Something that no one has mentioned here and that should be is that you don't want to just have a variety of grouts, setting materials, membranes and underlayments (for leveling) from different manufacturers no matter how good they are. If there is a problem, even if they all have 10 year warranties, its always the other guys fault. The major materials suppliers for tile setting systems where they provide a full line of products can do everything including the primers for the substrate up to the grout in the tile so that everything in the sandwich from the substrate and its prep to the top except the tile or stone itself is by one manufacturer. When you do that, the major manufacturers like Laticrete, Mapei, and a few others have lifetime warranties or life of the building warranties available. A few even include replacement of any tile damaged by the failure or the required repair of the failure. Even when the owner/developer does not want the extra comfort of that level of warranty, I still require the 'sandwich' of products from substrate and its prep up through the grout to be from a single manufacturer and that gets a default '10 year warranty' that the various manufacturer's make available. I also have language similar to John's above related to actual expansion joints, but that's really a different discussion beyond just crack isolation membranes. William William C. Pegues, FCSI, CCS, SCIP Affiliate WDG Architecture, Washington, DC | Dallas, TX Jerome J. Lazar, RA, CCS, CSI, SCIP Senior Member Username: lazarcitec Post Number: 779 Registered: 05-2003 Posted on Wednesday, February 29, 2012 - 01:27 pm:    Dale, was the latest TCNA manual ever issued in PDF? Lisa Goodwin Robbins, RA, CCS, LEED ap Senior Member Username: lgoodrob Post Number: 168 Registered: 08-2004 Posted on Wednesday, February 29, 2012 - 01:49 pm:    Jerome, I just received the new TCNA manual on CD. If it is small enough to email, I'll let you know. I typically recommend crack suppression membrane where the Architect wants a thin set installation for tiles larger than 12 by 12 on the floor, if I know about it. Does anyone else find it impossible to get the Architect to focus on tile installation? - Steven Bruneel, AIA, CSI-CDT, LEED-AP Senior Member Username: redseca2 Post Number: 324 Registered: 12-2006 Posted on Wednesday, February 29, 2012 - 01:59 pm:    FYI - The latest TCNA manual is quite a different beast than the previous editions: 2010 = 84 pages 2011 = 296 pages Now that it is a real "book", I am afraid that the days when a tile presenter gives away a dozen manuals at an office lunch and learn presentation are past. For crack isolation control we follow William's advice and specify 100-percent coverage at any location that isn't getting a 100-percent coverage crack isolation + waterproofing product. William C. Pegues, FCSI, CCS Senior Member Username: wpegues Post Number: 853 Registered: 10-2002 Posted on Wednesday, February 29, 2012 - 01:59 pm:    Lisa, Jerome, Read the floor flatness article for stone and tile floors in the March 2011 Specifier. The tables in that for tile sizes and grout joint widths reflected the new 2011 TCNA revisions. Big point is that it changes from 12 by 12 size for being a concern to 'any tile or stone where one side is more than 8 inches. William William C. Pegues, FCSI, CCS, SCIP Affiliate WDG Architecture, Washington, DC | Dallas, TX Gerard Sanchis Senior Member Username: gerard_sanchis Post Number: 65 Registered: 10-2009 Posted on Wednesday, February 29, 2012 - 02:31 pm:    On the west coast, where buildings are for the most part steel-framed and more flexible than concrete and masonry buildings, our office always specify a waterproofing/crack isolation membrane under tile on suspended floors. Most tile setting material manufacturers make systems that will provide both waterproofing and crack isolation. This applies to thin set tile regardless of size. For slabs on grade, I suppose that one could use the strip method over cracks but we specify the same system as for suspended slabs. For tiles set in conventional (thick) setting bed, again on suspended slabs, we specify a slip sheet (usually 6 mils polyethylene) under the setting bed to divorce the setting bed from the structural slab. Poly is more resistant than 15 lbs felt and its cost is minimal. This is similar to a conventional terrazzo installation, except that for terrazzo we use a thin sand layer in lieu of poly. Anne Whitacre, FCSI CCS Senior Member Username: awhitacre Post Number: 1246 Registered: 07-2002 Posted on Wednesday, February 29, 2012 - 08:23 pm:    I agree with Gerard. I ALWAYS have a membrane under EVERY tile installation, and ALWAYS use a modified setting bed. (with latex in it). I don't use the poly for anything. In addition, I've been asking for a warranty that the crack resistant membrane/the setting bed/ and the grout all be by the same manufacturer and compatible with each other. Dale Roberts CSI, CCPR, CTC, LEED Green Associate Senior Member Username: dale_roberts_csi Post Number: 92 Registered: 10-2005 Posted on Thursday, March 01, 2012 - 09:44 am:    Hi William I believe this is a typo regarding floor flatness “Big point is that it changes from 12 by 12 size for being a concern to 'any tile or stone where one side is more than 8 inches.” 2011 TCNA states for Subsurface Tolerance, for thin-bed ceramic tile installations when a cementitious bonding material will be used, including medium bed mortar: maximum allowable variation in the tile substrate – for tiles with all edges shorter than 15”, maximum allowable variation is Ό” in 10” from the required plane, with no more than 1/16” variation in 12” when measured from the high points in 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” when measured from the high points in the surface. For modular units, such as plywood panels or adjacent concrete masonry units, adjacent edges cannot exceed 1/32” difference in height. Should the architect/designer require a more stringent finish tolerance (e.g. 1/8” in 10”), the subsurface specification must reflect that tolerance, or the tile specification must include a specific and separate requirement to bring the subsurface tolerance into compliance with the desired tolerance. Such as the new thin tile 3mm to 4.5mm will need a flatter substrate. The question becomes who is to correct the substrate? And can you specify whether that is in the scope of the tile contractor or the contractor installing the substrate? Dale Roberts CSI, CCPR, CTC, LEED Green Associate Senior Member Username: dale_roberts_csi Post Number: 93 Registered: 10-2005 Posted on Thursday, March 01, 2012 - 09:52 am:    William, #5 Bond Coat TCNA has new language for coverage Mortar Coverage for ceramic tile: average contact area for dry areas is 80% and for wet areas is 95%. Mortar coverage is to be evenly distributed to support edges and corners Mortar Coverage for Natural Stone Tile: mortar coverage must be sufficient to prevent cracks in the stone resulting from voids in the setting bed. In dry and wet areas, the minimum coverage is 95% with no voids exceeding 2 square inches and no voids within 2” of tile corners. All corners and edges of the stone tiles must be fully supported, and back – parging, or back buttering, is recommended in all areas. Coating the back of tile, however does not constitute coverage, which is the area where the mortar makes contact with the tile and the substrate. William C. Pegues, FCSI, CCS Senior Member Username: wpegues Post Number: 854 Registered: 10-2002 Posted on Thursday, March 01, 2012 - 10:39 am:    TCNA has new language for just about everything, or modified anyway. When the page count more than triples, that's a lot of new words. I am not sure what specifically in your quote you are pointing to as a potential typo. As to who is responsible for floor flatness, the guiding point is that specifications do not address subcontractors. It is the General Contractor that is responsible. So I went into the slab finishing section for concrete (I use separate sections to address concrete with separate sections for general information to all types of concrete, reinforcing, formwork, structural, architectural, etc. and concrete finishing wherein I also have the flatness requirements for slabs). In that section I provide the flatness tolerances required for slabs with the different finishes that they will receive. I also include a reference to the section for underlayments and state that the contractor may achieve the flatness tolerances through the concrete itself or through the use of the specified underlayments. The underlayments also references back to concrete finishing for coordination purposes, and also references to the tiling section for single source responsibility for products and manufacturers and warranty requirements for the complete package of underlayments and tile setting materials. In the tiling section I refer back to underlayments tying the single source responsibility for products and manufacturers and warranty. I also require a reinstallation meeting for concrete, for underlayments and for tiling to assure that everyone knows the single source and warranty requirements. I don't care who the contractor assigns to install different parts, he is free to divide it up as he sees fit. The manufacturers that I use also do not have concerns on this either so long as any installer qualifications they have are met and those are spelled out in my sections as well. This is a fairly new process I have set up, started it in projects going out in October 2011. Several projects have gone through bidding and award and are underway, no contractor has raised any qualifications or concerns at this point. And on one of them this was inserted as an addendum modification and not much else in that addendum so its not like they don't see it. We have always had problems with flatness in the DC Metro area. No matter what you ask for, and no matter whatever reason, the concrete slab flatness almost always gets qualified to 1/4 inch (or the Ff/Fl equivalent) everywhere with a cure and seal compound (even if you specify moist cure for finish requirements). And when you get it its a good day when its even close to 1/4 inch, its often not. Are there issues with this kind of system? Yes, but if you want decent tile, you are pretty stuck. Especially if you are dealing with post tension slabs and lots of large open tiled areas that have large format tiles (24 inches and larger on a side). When I started doing this, I sat down with tile setting system manufacturers and went over this, and got their input. I also went out to them for different applications that I typically run into and had them give me their recommendations for each of these that address the setting system from the slab (or whatever substrate) up through grout. So I go out the door with complete systems of specific products for each application. I am currently getting additional manufacturers and their products, and I have a complete vetting process so that each gets to see the other's proposed system before it goes into my master, and if I get something very different, I go out to them direct for that. I get responses back very quickly. William William C. Pegues, FCSI, CCS, SCIP Affiliate WDG Architecture, Washington, DC | Dallas, TX William C. Pegues, FCSI, CCS Senior Member Username: wpegues Post Number: 855 Registered: 10-2002 Posted on Thursday, March 01, 2012 - 12:11 pm:    All, It was pointed out to me in my last post above that apparently my setting to turn off auto spell correction had been reset with a recent update. It does not recognize the word PREinstallation so it changed it to REinstallation. Everywhere it says 'reinstallation' above, change that to 'preinstallation'. Thanks! William C. Pegues, FCSI, CCS, SCIP Affiliate WDG Architecture, Washington, DC | Dallas, TX Dale Roberts CSI, CCPR, CTC, LEED Green Associate Senior Member Username: dale_roberts_csi Post Number: 94 Registered: 10-2005 Posted on Thursday, March 01, 2012 - 12:12 pm:    Hi William I just wanted to make it clear that the new standard uses 15” as the breaking point for a large format tile, not 8 x 8 or 12 x 12. Thanks for the reminder that it is up to the GC to hold them accountable for the substrate tolerance. Tile contractors want a level playing field when bidding on projects; so much of their work is dependent on others. Tile is a finish an inadequate substrate can cause a failure in the tile. Anne Whitacre, FCSI CCS Senior Member Username: awhitacre Post Number: 1247 Registered: 07-2002 Posted on Thursday, March 01, 2012 - 04:52 pm:    I was getting a lot of pushback from project teams about thin setting versus anything else, even for large tiles, and I found the answer for that. Ask the tile manufacturer what they require for flatness in the slab in order to warranty their tile. Invariably, its 1/8" in 10' (even if you have to look at the small print) and they will disavow breakage if the floor is not that flat. This has been a great help to me, since the tile product reps all say "Can be thin set" no matter how large the thing is. I got tired of sounding like a shrew in the office, and so I simply said "get the recommended flatness in writing from the manufacturer". I am very conservative about tile installations, but even I've allowed 12" x 12" tiles to be thin set if fully back buttered. (and that's a big if: we had a problem with a project where 12" x 12" tiles were breaking, and when they were forensically examined, the tiles averaged less than 40% coverage across the back. ) John Bunzick, CCS, CCCA, LEED AP Senior Member Username: bunzick Post Number: 1360 Registered: 03-2002 Posted on Thursday, March 08, 2012 - 04:22 pm:    Jerome, As to whether the architect needs to indicate on the drawings the extent to use crack isolation membrane: If the TCNA method is specified or otherwise indicated, and it is one of the ones using crack isolation membrane, then that should cover it.