BUILDCALCTILE & THINSET SPEC
CONTRACTOR SPECIFICATION TAKE-OFF

8' × 10' Bathroom Floor Tile & Thinset Takeoff

Tiling an 8' × 10' master bathroom floor (80 sq ft) with popular 12" × 24" large format porcelain tiles requires accounting for a minimum 10% cutting and layout waste factor, yielding 88 sq ft of tile (6 full boxes at 16 sq ft/box). Large format tiles require a minimum ½" × ½" square notch trowel to achieve proper 85%+ mortar coverage, consuming 2 to 3 50lb bags of polymer-modified thinset mortar. Six 3' × 5' sheets of ½" cement backer board (Durock or HardieBacker) provide an impervious deflection-resistant substrate.

Tile & Grout Dimensions

88 SQ FT ORDER
GROUT TYPE
CEMENT BACKER BOARD
TILE SUBSTRATE CUTAWAY & GRID LAYOUT
Format: 12X24 (1/8" Joint)88 SQ FT (6 BOXES)
Tile assembly schematic for 10' x 8' roomSUBSTRATE ASSEMBLY CROSS-SECTION1. PLYWOOD SUBFLOOR (3/4" T&G)2. 1/2" CEMENT BACKER BOARD3. THINSET MORTAR (1/2" × 1/2" Square Notch (Large Format))4. 12X24 TILE & GROUTPLAN VIEW GRID & JOINT SPACING1/8" SPACER10' × 8' AREA (88 SQ FT ORDER)
Tile Quantity:6 Boxes (44 pcs)88 sq ft total
Thinset Mortar:3 Bags (50 lb)1/2" Notch
Grout Requirement:5 lbs (1 Bags)SANDED (1/8")
Underlayment / Backer:6 Sheets (3×5)2 bx screws
Trade Fulfillment & Jobsite LogisticsEstimated Materials Cost: $539
RETAIL STORE PICKUPDIY TRUCK / VAN
6 Tile Boxes
88 sq ft tile + 3 Bags Thinset (50lb)
Total Dry Weight:551 lbs
FLATBED PALLET DELIVERYCOMMERCIAL HAULER
1 Banded Pallet
Shrink-wrapped pallet drop with liftgate & pallet jack
Jobsite Placement:Curbside Drop

Contractor Trade Best Practices & Code FAQs

What trowel size is required for 12x24 large format tile?

For any tile with at least one side measuring 15 inches or greater (large format tile / LFT), ANSI A108 standards require using a 1/2" × 1/2" square notch or 1/2" U-notch trowel. Furthermore, each tile should be back-buttered (flat skim coat of mortar applied to the tile backside) to guarantee minimum 85% mortar coverage on floors and eliminate hollow spots that lead to cracked tiles.

Should I use sanded or unsanded grout for bathroom floor tiles?

Use sanded grout (or advanced polymer/epoxy grout) for joints 1/8" or wider. Sand aggregate provides compressive strength and prevents shrinkage cracking across the joint. Unsanded grout should only be used for narrow joints under 1/8" or on polished marble and glass tiles that might scratch from quartz sand particles.

Can you tile directly over plywood subfloors?

Never tile directly over standard OSB or CDX plywood in wet areas. Wood expands and contracts with ambient humidity, causing rigid tile and grout to buckle or shear off. Always install a 1/2" cementitious backer board (Durock, Wonderboard) embedded in a thinset bed and screwed with corrosion-resistant fasteners, or install an uncoupling waterproofing membrane (such as Schluter DITRA).