SUBSTRATE REQUIREMENTS - CHEMBOND

1 Properly preparing a SUBSTRATE is one of the most importantsteps in a tile best installation is only as goodas the SUBSTRATE beneath the time to properly prepare a SUBSTRATE and address job-site conditions should be a priority. For best results, see individual ChembondProduct Data Sheets and this document for SUBSTRATE environmental conditions and protect workduring and after the installation. Comply with trade andindustry standards as well as the manufacturer's necessary,build a temporary shelter and use indirect auxiliary heaters to maintain an adequate temperature within the working environment and onthe installation temporary heaters to the exterior to preventdamage to the installation, or injury to personnel fromcarbon monoxide tiled areas,maintain SUBSTRATE and ambient temperatures at no less than 10 C (50 F) and no greater than 35 C (95 F)

2 During installation and for atleast 7 days after completion, unless otherwise indicatedin the product instructions and/or ANSI A108 ExaminationBefore work commences, examine the areas to be coveredand report any deficiency or adverse condition in writing to the general contractor,owner, developer or not proceed with work until surfaces and conditionscomply with REQUIREMENTS indicated in the manufacturer's instructions and in ANSI A108. For details, refer to the TTMACH andbook for ceramic tile REQUIREMENTS 1. surfaces must be structurally dry, sound, solid,dimensionally stable, clean and free of any substance orcondition that may reduce or prevent the adhesive'sbond to the include, but are not limitedto, concrete sealers or curing agents, dirt, wax, tar, paintand loose toppings.

3 If the surface contains these substances, they must be mechanically : The use of solvents, adhesive removers or acidetching is not Unless sanding or scraping a slab can produce a clean SUBSTRATE that is free from contamination, more aggressive methods such as grinding, shotblasting andscarification should be : It is important to follow safety guidelines forthe specific SUBSTRATE , as well as local, provincialand federal regulations. supporting surfaces should be structurally sound,solid, stable, level, plumb, and true to a tolerance in planeof 3 mm in 2,44 m (1/8" in 8 ft.)

4 For walls and 6 mm in3,05 m (1/4" in 10 ft.) for floors. (See current TTMAC guide and ANSI guidelines for details.)d. substrates should be free of deflection that could damage the flooring or installation areindustry standards required by most floor-covering manufacturers. In all cases, the structural design of thefloor should not allow a deflection greater than 1/360 of the span (1/720 for natural-stone installations) whenmeasured under a 136-kg (300-lb.) concentrated load(see ASTM C627). installation over a radiant-heating system is approved,the system should be turned off at least 24 hours before and until 48 hours after the installation.

5 Prior toinstallation, check with the ceramic tile manufacturerregarding the radiant-heating system current TTMAC Detail surfaces should be dry and fully cured (for atleast 28 days), and conform to ACI 302 standards. Theyalso should have a minimum density of 1,601 kg per m3(100 lbs. per ) as well as a compressive strengthgreater than 20,7 MPa (3,000 psi) for residential installations and 30 MPa (4,350 psi) for REQUIREMENTS For Tile ASTM F1869, water vapor emission from all slabsshould not exceed 1,36 kg per 92,9 m2 (3 1,000 ft2) over 24 hoursunless otherwise F2170 is also a method of detecting moisture (relative humidity) in a concrete slab.

6 Moisture metersare useful in verifying moisture's presence and determining where to set up calcium chloride an accurate test, the floor-covering industry as a whole has not determined an acceptable percentage ofrelative humidity. Floors with greater than 1,36 kg per92,9 m2(3 lbs. per 1,000 ) over 24 hours or with relative humidity greater than 75% should be pretreatedwith a compatible moisture-reduction and below-grade concrete slabs must beinstalled over an acceptable and effective vapor barrier,per industry porosity should be is always a goodpractice to perform bond tests before large-scale concrete surfaces should be wood-floated orbroom-finished, because a smooth steel-troweled finishcan reduce adhesion and greatly extend the products'setting needed.

7 Mechanical shotblasting can beused to roughen an excessively smooth prepare a concrete SUBSTRATE to a minimumICRI CSP #3 profile for setting mortars, and an ICRI CSP#5 profile for levelers and slabs(that is, slabs with an extremely smooth finish due toexcessive power-troweling) are not absorbent (porous) concrete surfaces canpull moisture from setting materials too rapidly. Surfacegrinding can be used to smooth an excessively porous or rough surface. If surface grinding is unfeasible, keepthe concrete SUBSTRATE continuously moist for at least 24 hours before work remove all excesswater or standing water, allowing the surface to becomealmost dry to provide an SSD (saturated surface-dry) condition before installing the setting : Self-leveling products and their primers should notbe installed over porous pH levels range from 5 to 9 on the pH scale.

8 Use distilled water and litmus paper or a pH pencil to identify the pH levels that are too high ortoo low by removing surface salts through sanding orscrubbing with clean :A high-alkali slab (with 10 to 14 pH) can signify amoisture a pH problem is found,the slabshould be tested for CEMENT BACKER UNITSC ement backer units (CBUs) should conform to the qualitystandard REQUIREMENTS of ANSI They must be installedper the instructions of the CBU manufacturer and in strictaccordance with ANSI standards for interior installation of cement backer EXTERIOR WALL SURFACESWhen surface waterproofing is required, apply a manufacturer's approved thin load-bearing waterproofingmembrane with a flat trowel.

9 If necessary and prior to waterproofing, apply a thin coat of a manufacturer'sapproved flexible acrylic Portland-cement mortar about 1,5 to 3 mm (1/16" to 1/8") thick to cover the entire concrete,masonry or CBU SUBSTRATE . Allow the coating to dry and cure for at least 24 hours before installing tiles. (Seerespective Product Data Sheets for details.) Quality wood substrates are typically acceptable for residential and light commercial applications in dry wood subfloors shall be properly ventilated and acceptable to local codes and REQUIREMENTS . Local buildingcodes as well as TTMAC guidelines should be followed forinstalling a wood :It is important to know and understand that your choice of SUBSTRATE is an approvedunderlayment underlaymentsmust be of Group 1 exterior-grade plywood, CC plugged or better,conforming to CSA 0121.

10 Plywood and flooring manufacturer's approved subfloor and underlayment should not be used in wet areas. Plywood should not be used as a SUBSTRATE on walls. Plywood subfloors and underlayments should consistof at least two layers, each of a nominal 16 mm (5/8")in thickness,allowing a minimum total thickness of 32mm (1-1/4") vs. a minimum 38 mm (1-1/2") forinstalling natural stone. Plywood surfaces should be installed with the smoothside facing upward,with the face grain running perpendicular to the framing. When using a latex-modified thin-set mortar or ceramic-tile adhesive for floor-tile installations, leave a gap of 3 mm (1/8") between sheets.