Thinset cement, to which polymers have been added, is commonly called latex-Portland cement mortar. In fact, this term is a bit of a misnomer. The original polymers used to modify thinset were based on latex and the term originates from their use. Today, there are over 10,000 polymers considered by cement chemists when formulating their products. Polymers such as EVA, PVA, SBR, and others are all commonly used in the industry. Many of these polymers are acrylics and not latex chemicals. The use of these polymers allows specific properties to be imparted to the cement - commonly, freeze/thaw resistance, improved flexibility, and improved adhesion. There are also polymers used to make the cement waterproof or sufficiently elastic so that it acts like an anti-fracture membrane.
The American National Standards Institute (ANSI) set minimum performance levels for latex-Portland cement mortars in the A118.4 and the A118.11 specifications.

What is (unmodified) thinset mortar, dryset mortar or drybond mortar? Thinset mortar is a blend of cement, very finely graded sand, and a water retention compound that allows the cement to properly hydrate. Tile set by the thinset method is adhered to the substrate with a thin layer of "thinset" cement. The terms thinset cement, thinset mortar, dryset mortar and drybond mortar are synonymous. This type of cement is designed to adhere well in a thin layer - typically not greater than 3/16th thick. For example, a 3/8" notch trowel will produce a 3/16th inch thick coating after the tiles are pressed in to the cement. While very minor adjustments in height can be made, this method is not appropriate for adjusting the level or flatness of a surface - rather the tile will follow the plane of the substrate.
Dryset thinset mortars are strong and unaffected by continuous exposure to water. They are also somewhat brittle and absorbent.
Set up time is 12-24 hours full cure is 28 days.
The American National Standards Institute (ANSI) defines the properties of thinset mortar in the A118.1 specification.

Modified thin-set is sand and cement, polymer enhanced with latex additives,however the term latex is a broad explanation of what is in todays thinsets. True latex is not even in most of modern thin-sets, it is chemicals that produce the similiar result, added bonding, greater strength, longer life span greater flexibility.
We have heard the arguement that modified thinset will not dry behind a product like Ditra or Kerdi, this is false statment and an attempt to misdirect the public and installers alike into false sense of security to coinside with Schluter Systems required warranty applications.
I have used modified thinset with Schluters products and had excellent results.I have used unmodified thinset with Schluter products and had terrible failures.... of course Schluter says it is the type of thinset, the expiration date on the thinset, or the installer.( Never their regressive install method)
Not only will modified thinset it dry, it will cure better, harder etc. It will take longer to cure, this is true, but it will cure and perform better than any unmodified.
The set time is about 12-72 hours, the cure time is about 11-28 days. Modified thinset will continue to cure for years.
I advise my installers to allow three days set time prior to grouting any shower.We do not compromise quality for speed.If the customer wants a quick sloppy job, we will take the contract.

SpiderWeb Uncoupling underlayment
Ceramic Floor Tile Installation Systems Using the Robinson-Type Floor Tester Resilient Floor Covering Institute � (RFCI) Recommended Work Practices for Removal of Resilient Floor Coverings Tile Council of North America (TCNA) � TCNA Handbook for Ceramic Tile Installation, TCNA Method EJ171 TECHNICAL PROPERTIES Results based on applicable ANSI test specifications Property Results Thickness 2 mm Weight <.1 lbs./sq. ft. Robinson Floor Test (Concrete) Heavy Bacteria and Fungus Resistance No Growth
ENVIRONMENTAL CONSIDERATIONS
Custom Building Products is committed to environmental responsibility in both products produced and in manufacturing practices.

PREPARATORY WORK
General Surface Preparation:
Surfaces must be structurally sound, clean, dry and free from grease, oil, dirt, curing compounds, sealers, adhesives or any other contaminants that would prevent a good bond. Glossy or painted surfaces must be sanded, stripped and cleaned of waxes, dirt or any contaminants.
Existing Ceramic Tile or Resilient Flooring:
Resilient flooring or plastic laminates must be well bonded, clean and free of all contaminates. Roughen the surface by sanding or scarifying, rinse and allow to dry. Do not sand flooring containing asbestos. For existing well-bonded ceramic tile, mechanically abrade with carborundum stone. Rinse and allow to dry. When sanding we recommend the use of an approved respirator.
Cutback Adhesive over Concrete :
Adhesive layers must be removed as they reduce mortar bond strength to cement surfaces. Use extreme caution as adhesives may contain asbestos fibers. Do not sand or grind adhesive residue, as harmful dust may result. Never use adhesive removers or solvents, as they soften the adhesive and may cause it to penetrate into the concrete. Adhesive residue must be wet-scraped to the finished surface of the concrete, leaving only the transparent staining from the glue. Do a test bond area first, to determine desirable results. Refer to the RFCI Pamphlet, �Recommended Work Practices for Removal of Resilient Floor Coverings� for further information.
Cementitious Surfaces:
Concrete slabs must be cured a minimum 24 hours and accept water penetration. Test by sprinkling water on various areas of the substrate. If water penetrates, then a good bond can be achieved. If water beads, surface contaminants are present and loss of adhesion may occur. The contaminants should be removed before installation. Concrete must be free of efflorescence and not subject to hydrostatic pressure. Can be used over exterior concrete where moisture (vapor transmission) never exceeds a reading above 12 lbs. (5.4 kg). Concrete slabs should have a broomed or brushed finish to enhance the bond. Smooth concrete slabs must be roughened to ensure a good bond.
Gypsum Substrates:
Gypsum substrates must have a PSI greater than 2000 and must first be primed or sealed per manufacturer�s instructions. When using thin-set applied SpiderWeb, all gypsum substrates must be coated with RedGard� Waterproofing and Crack Prevention Membrane or Custom� 9240 Waterproofing and Anti-Fracture Membrane.
Wood Substrates:
Plywood flooring including those under resilient flooring must be structurally sound, built to industry standards, and deflection should not exceed L/360 for tile or L/720 for stone.
METHODS
Mortar and Notch Requirement
Using a thin-set mortar that meets ANSI A118.4 and/or A118.11, apply the thin-set mortar using a 1/4" x 3/16" (6 x 4.8 mm) v-notch trowel to the substrate. Be careful not to trowel out more mortar than you can cover in the specified open time with SpiderWeb Uncoupling Mat. Installing SpiderWeb Uncoupling Mat Apply the SpiderWeb Uncoupling Mat to the floor, fleece side down. Embed the matting into the bonding mortar using a float or screed joining sections of mat, simply align end and side sections of adjacent sheets. Make sure to occasionally check the transfer of the bonding mortar to the mat. Lift up a corner of the matting to check coverage. Proper installation results in full contact between the fleece webbing and the thin-set mortar.
Waterproofing
Each roll of SpiderWeb Uncoupling mat is waterproof and creased on one side allowing it to easy fold up the wall. For a waterproof installation, start by installing SpiderWeb Uncoupling Mat on the perimeter on the floor and folding it up the wall before filling in the center portion of the floor. Inside corners can be pieced together by cutting two mats at a 45� and joining them. Make as few cuts as possible and join all seams with SpiderWeb Seam Sealing Tape or RedGard Waterproofing and Crack Isolation Membrane to completely waterproof the installation

Installing Tile Over SpiderWeb Uncoupling Mat
Tile can be installed over SpiderWeb as soon as it has been pressed into place. While working on the mat, place boards on the mat directly under you to prevent damage. Flat coat a mortar such as VersaBond� Fortified Thin-Set Mortar through the mesh being sure to completely fill all of the depressions in the mat first. Then, thin-set and comb additional mortar over the matting using a trowel that is appropriate for the size of the tile. Completely embed the tiles in the setting material. Periodically remove and check a tile to ensure that full coverage is being attained.
Mortar Selection
As described in the TCNA Handbook for Ceramic Tile Installation (2009), a polymer modified (ANSI 118.4) mortar is �required for the installation of porcelain tile�, and an ANSI A118.11 mortar should be used when bonding to exterior glue plywood. Custom Building Products supports the use of polymer modified mortars whenever required. SpiderWeb Uncoupling Mat is also compatible with ANSI A118.1 qualified non-modified mortars for basic tile installation.
Coverage
1 M x 30 M roll will cover 323 square feet.
BUILDING CODES
Installation must comply with the requirements of all applicable local, state and federal code jurisdictions

Limited Product Warranty
This product is eligible for Custom Building Products 10 Year Installation Systems Warranty and a Lifetime Residential warranty.
Custom Building Products warrants to the original consumer purchaser that its product shall be free from defects in material and workmanship under normal and proper usage for a period of one year following the date of original purchase. Custom�s sole liability under this warranty shall be limited to the replacement of the product. Some states, countries or territories do not allow the exclusion or limitation of incidental or consequential damages, so the above limitation or exclusion may not apply to you. This warranty will not extend to any product which has been modified in any way or which has not been used in accordance with Custom�s printed instructions. Custom makes no other warranties either expressed or implied. This warranty gives you specific legal rights, and you may have other rights that vary from state to state or from one country/territory to another. For details and complete warranty information, visit custombuildingproducts.com.