EIFS calculator

1. Net wall area
   length × height − openings
   40 ft × 10 ft − 0 SF = 400.00
2. Sheathing joints to treat
   net SF × 12 LF per 32 SF sheet (4×8)
   400 × 0.375 = 150.0
3. WRB coating
   net SF ÷ SF per unit, rounded up
   400 ÷ 450 = 1
4. Adhesive
   net SF ÷ SF per unit, rounded up
   400 ÷ 90 = 5
5. EPS boards (2 × 4)
   net SF ÷ 8 SF per board, rounded up
   400 ÷ 8 = 50
6. EPS board feet
   net SF × thickness (in)
   400 × 2 = 800.0
7. Base coat
   net SF ÷ SF per unit, rounded up
   400 ÷ 80 = 5
8. Mesh per roll after the lap
   (roll width − side lap) ÷ 12 × roll length
   (38 − 2.5) (in) ÷ 12 × 150 ft = 443.75
9. Standard mesh rolls
   net SF ÷ SF per roll, rounded up
   400 ÷ 443.75 = 1
10. Backwrap and detail mesh
    base + top + opening perimeter + 2 × expansion joints; ÷ roll length, rounded up
    (40 + 0 + 0 + 2 × 0) ft ÷ 150 = 1
11. Starter / drainage track
    base of wall + opening heads
    40 + 0 = 40.00
12. Primer
    net SF ÷ SF per unit, rounded up
    400 ÷ 750 = 1
13. Finish
    net SF ÷ SF per unit, rounded up
    400 ÷ 140 = 3

Where the numbers come from

• IRC R703.9: EIFS with drainage on all framed walls (90% drainage efficiency, ASTM E2273, WRB behind it); EIFS without drainage only over concrete or masonry, 6" above grade2021 IRC as reprinted in the 2021 Seattle Residential Code. The manufacturer's published installation instructions and the project spec govern every layer.Source
• WRB / air barrier coating: Sto Gold Coat 5 gal: 450 SF on glass-mat gypsum, plywood, cement board or concrete (10 mils); 300 SF on OSB (20 mils); 80 SF on CMU (60 mils) · Dryvit Backstop NTX Texture 5 gal: 250 SF on fiberglass-faced gypsum (joints included); 250 SF + 300 LF of sheathing joint per pail on paper-faced gypsum; 200 SF on concrete or masonryDryvit: https://www.dryvit.com/resource/download/DS_455BackstopNTX.pdf and DV-300 (NTX application instructions). The page uses the low end of each range and switches the rate when you pick the sheathing or masonry type. Where a sheet doesn't list a base (Sto: paper-faced gypsum; Dryvit Texture: plywood, OSB) the nearest listed rate is used — check with the maker. Sheathing joints (4' × 8' sheets): each sheet adds half its perimeter, 12 LF per 32 SF = 0.375 LF per SF (derived).Source
• Adhesive: Sto BTS Plus 47 lb bag: 90–135 SF over sheathing (½" × ½" U-notch, 2" apart) · Dryvit Genesis DM 50 lb bag: 100 SFDryvit: https://www.dryvit.com/resource/download/DS_452GenesisDM.pdf. Vertical notched-trowel ribbons let water drain on drainage EIFS. Rough masonry takes much more (BTS Plus 30–45 SF) — change the box.Source
• EPS board: 2' × 4' boards (8 SF) at most; 1 board foot = 1 SF × 1"Dryvit DV-169. Boards = net SF ÷ 8; board feet = net SF × thickness in inches; CY = board feet ÷ 12 ÷ 27 (derived).Source
• Base coat: Sto BTS Plus 47 lb bag: 80–125 SF · Dryvit Genesis DM 50 lb bag: 120 SFAbout 1/16" thick with standard mesh. High-impact mesh gets its own base coat layer, then the standard mesh and base coat go over the whole wall, so the page adds the high-impact SF once more.Source
• Reinforcing mesh: Sto Mesh 38" × 150' · Armor Mat 38" × 75' · Detail 9.5" × 150' — Dryvit Standard 48" × 150' · Panzer 15 48" × 75' · Detail 9½" × 150' · Corner 9¼" × 150'Dryvit: https://www.dryvit.com/resource/download/ds413_Reinforcing_Mesh.pdf. Standard mesh laps 2½" at edges (Dryvit US, Sika; Dryvit Canada says 3"), so a 38" × 150' roll covers (38 − 2.5) ÷ 12 × 150 = 443.75 SF and a 48" × 150' roll 568.75 SF (derived). High-impact mesh is butted, not lapped. Backwrap at the base, top and openings uses detail mesh; diagonal pieces at opening corners are not counted.Source
• Starter track and vents: Track along the base and over opening heads; Dryvit Outsulation MD vent assemblies every 10 ft along the baseSource
• Primer and finish: StoPrime Sand 5 gal: 750–1,100 SF · Stolit 5 gal: .75 160–190, 1.0 140–165, 1.5 120–145, 2.0 75–100, 3.0 55–70 SF · Dryvit Color Prime 50 lb: ~1,500 SF · DPR 70 lb: Quarzputz 140, Sandblast 150, Sandpebble 130, Sandpebble Fine 160, Mojave 125 SFAlso: https://stocorp.com/wp-content/content/Products_TechService/Coatings/Product%20Bulletins/PB_80801_Sto_Prime_Sand_EN.pdf · https://www.dryvit.com/resource/download/DS_410ColorPrime.pdf · https://dryvit.com/resource/download/ds416_DPR_Finishes.pdf. Check: Sandpebble 130 SF × 61.69 mils wet = 0.668 ft³ = 5.0 gal, a full pail.Source
• Sealant joints: At openings and expansion joints, at least ¾" wide; gallons = LF × 12 × width × depth ÷ 231Check: a ¼" × ¼" joint gives 231 ÷ (0.25 × 0.25 × 12) = 308 LF per gallon, the same as Dryvit's Dymonic 100 chart. Depth comes from the sealant maker — the page counts gallons only when you enter it. Backer rod LF = sealant LF.Source