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Mortar mix calculator
How much mortar does your wall need? Enter the wall area, unit, joint width and mortar type to see the volume, the bags to buy, and the cement, lime and sand to mix.
★ CONSTRUCTION · MASONRY · REFERENCE TABLE #242
Mortar Mix Chart: Ratios, Strength & Bags Per Wall 2026
6.05 cu ft of mortar — 11 bags (80 lb) for 100 sq ft. A 100 sq ft brick wall with a 3/8 in joint needs 5.50 cu ft of type N mortar. Enter your wall size, unit, joint and type to see your mortar.
Type N at 750 psi is the general-use mix — pick the type first
Mortar is not one mix: the type sets the strength, and the strength sets where the wall can go. Type M (2,500 psi) is for below-grade work and foundations; type S (1,800 psi) is for below-grade and exterior load-bearing walls; type N (750 psi) is the general-use mix for above-grade exterior veneer; type O (350 psi) is for interior non-load-bearing walls; type K (75 psi) is for historic restoration. On the defaults — wall area 100 sq ft, unit brick, joint 3/8 in, mortar type N, waste 10% — the mortar volume is 5.50 cu ft, the volume with waste is 6.05 cu ft, that is 11 80-lb bags and 14 60-lb bags, the cement is 0.95 cu ft (1 bag), the lime is 0.95 cu ft (1 bag) and the sand is 5.67 cu ft. The volume tables below use the rounded rates the model uses — the calculator works from the same rates.
Mortar types (ASTM C270)
| Type | Cement : lime : sand (parts by volume) | 28-day strength (psi) | Use |
|---|---|---|---|
| M | 1 : 0.25 : 3 | 2,500 | Below grade / foundations / retaining walls |
| S | 1 : 0.5 : 4.5 | 1,800 | Below grade / exterior load-bearing |
| N | 1 : 1 : 6 | 750 | Above grade / exterior veneer / general use |
| O | 1 : 2 : 9 | 350 | Interior non-load-bearing |
| K | 1 : 3 : 12 | 75 | Historic restoration |
Mortar volume per sq ft of wall (cu ft / sq ft)
| Unit | Joint width | Rate (cu ft / sq ft) |
|---|---|---|
| Brick | 1/4" | 0.038 |
| Brick | 3/8" | 0.055 |
| Brick | 1/2" | 0.069 |
| Brick | 5/8" | 0.083 |
| Block | 1/4" | 0.030 |
| Block | 3/8" | 0.044 |
| Block | 1/2" | 0.058 |
| Block | 5/8" | 0.072 |
At the defaults — wall area 100 sq ft, unit brick, joint 3/8 in, mortar type N, waste 10% — the volume is 5.50 cu ft, the volume with waste is 6.05 cu ft, the 80-lb bags are 11, the 60-lb bags are 14, the cement is 0.95 cu ft (1 bag), the lime is 0.95 cu ft (1 bag) and the sand is 5.67 cu ft. Check the identities: V = area × rate; Vw = V × (1 + waste ÷ 100); 80-lb bags = ceil(Vw ÷ 0.6); 60-lb bags = ceil(Vw ÷ 0.45); cement = Vw × cement share × 1.25; lime = Vw × lime share × 1.25; sand = Vw × sand share × 1.25; cement bags = ceil(cement cu ft); lime bags = ceil(lime cu ft). The dry-mix allowance is ×1.25 on component volumes. Rounding convention: totals are computed from unrounded values, so rounded parts may differ by a cent from their rounded sum.
| Scenario | Volume | With waste | 80-lb bags | 60-lb bags | Sand |
|---|---|---|---|---|---|
| Default (100 sq ft brick, 3/8 in joint, type N, 10% waste) | 5.50 cu ft | 6.05 cu ft | 11 | 14 | 5.67 cu ft |
| 200 sq ft | 11.00 cu ft | 12.10 cu ft | 21 | 27 | 11.34 cu ft |
| 500 sq ft | 27.50 cu ft | 30.25 cu ft | 51 | 68 | 28.36 cu ft |
| 50 sq ft | 2.75 cu ft | 3.03 cu ft | 6 | 7 | 2.84 cu ft |
| Joint 1/4 in | 3.80 cu ft | 4.18 cu ft | 7 | 10 | 3.92 cu ft |
| Joint 1/2 in | 6.90 cu ft | 7.59 cu ft | 13 | 17 | 7.12 cu ft |
| Block, 3/8 in joint | 4.40 cu ft | 4.84 cu ft | 9 | 11 | 4.54 cu ft |
| Block, 1/2 in joint | 5.80 cu ft | 6.38 cu ft | 11 | 15 | 5.98 cu ft |
| No waste (0%) | 5.50 cu ft | 5.50 cu ft | 10 | 13 | 5.16 cu ft |
| Waste 20% | 5.50 cu ft | 6.60 cu ft | 11 | 15 | 6.19 cu ft |
| Type M | 5.50 cu ft | 6.05 cu ft | 11 | 14 | 5.34 cu ft |
| Type S | 5.50 cu ft | 6.05 cu ft | 11 | 14 | 5.67 cu ft |
| Type O | 5.50 cu ft | 6.05 cu ft | 11 | 14 | 5.67 cu ft |
| Type K | 5.50 cu ft | 6.05 cu ft | 11 | 14 | 5.67 cu ft |
The worked example, line by line
Setup: wall area 100 sq ft, unit brick, joint 3/8 in, mortar type N, waste 10%.
Line 1 — the volume. 100 sq ft × 0.055 cu ft/sq ft = 5.50 cu ft.
Line 2 — the volume with waste. 5.50 cu ft × 1.10 = 6.05 cu ft.
Line 3 — the bags. 6.05 cu ft ÷ 0.6 = 10.08, rounded up to 11 80-lb bags; 6.05 cu ft ÷ 0.45 = 13.44, rounded up to 14 60-lb bags.
Line 4 — the mix. Type N is 1:1:6, so the shares are 1/8, 1/8 and 6/8. Cement: 6.05 × 1/8 × 1.25 = 0.95 cu ft (1 bag). Lime: 6.05 × 1/8 × 1.25 = 0.95 cu ft (1 bag). Sand: 6.05 × 6/8 × 1.25 = 5.67 cu ft.
Reverse: the area for 20× 80-lb bags is 198.35 sq ft (exact 198.3471); at 198.34 sq ft it is 20 bags, at 198.35 sq ft it is 21. The area for V = 10.00 cu ft is 181.82 sq ft (exact 181.8182); at 181.81 sq ft V is 9.9996, at 181.82 sq ft it is 10.0001. The waste for Vw = 7.00 cu ft is 27.27% (exact 27.2727%); at 27.27% Vw is 6.9999, at 27.28% it is 7.0004. The area for 15× 60-lb bags is 111.57 sq ft (exact 111.5702); at 111.57 sq ft it is 15 bags, at 111.58 sq ft it is 16. The area for sand 10.00 cu ft is 176.31 sq ft (exact 176.3085); at 176.30 sq ft sand is 9.9995, at 176.31 sq ft it is 10.0001. The area for 25× 80-lb bags is 247.93 sq ft (exact 247.9339); at 247.93 sq ft it is 25 bags, at 247.94 sq ft it is 26.
Every branch, checked
200 sq ft: V 11.00 cu ft, with waste 12.10 cu ft — 21 80-lb bags, 27 60-lb bags; cement 1.89 cu ft (2 bags), lime 1.89 cu ft (2 bags), sand 11.34 cu ft. Doubling the wall doubles everything — the bags go from 11 to 21, not 22, because 12.10 cu ft is just over 20 bags' worth.
500 sq ft: V 27.50 cu ft, with waste 30.25 cu ft — 51 80-lb bags, 68 60-lb bags; cement 4.73 cu ft (5 bags), lime 4.73 cu ft (5 bags), sand 28.36 cu ft. At 500 sq ft the sand alone is 28.36 cu ft — about a cubic yard.
50 sq ft: V 2.75 cu ft, with waste 3.03 cu ft (exact 3.025) — 6 80-lb bags, 7 60-lb bags; cement 0.47 cu ft (1 bag), lime 0.47 cu ft (1 bag), sand 2.84 cu ft. A small wall still needs a whole bag of cement and a whole bag of lime — the bags round up.
Joint 1/4 in: V 3.80 cu ft, with waste 4.18 cu ft — 7 80-lb bags, 10 60-lb bags; cement 0.65 cu ft (1 bag), lime 0.65 cu ft (1 bag), sand 3.92 cu ft. A narrower joint takes a third less mortar than the 3/8 in default.
Joint 1/2 in: V 6.90 cu ft, with waste 7.59 cu ft — 13 80-lb bags, 17 60-lb bags; cement 1.19 cu ft (2 bags), lime 1.19 cu ft (2 bags), sand 7.12 cu ft. A wider joint takes a quarter more mortar than the 3/8 in default.
Block, 3/8 in joint: V 4.40 cu ft, with waste 4.84 cu ft — 9 80-lb bags, 11 60-lb bags; cement 0.76 cu ft (1 bag), lime 0.76 cu ft (1 bag), sand 4.54 cu ft. Block walls take less mortar per square foot than brick at the same joint — the units are bigger, so there are fewer joints.
Block, 1/2 in joint: V 5.80 cu ft, with waste 6.38 cu ft — 11 80-lb bags, 15 60-lb bags; cement 1.00 cu ft (1 bag), lime 1.00 cu ft (1 bag), sand 5.98 cu ft. A block wall at a 1/2 in joint needs 5.80 cu ft — about the same as a brick wall at 3/8 in.
No waste (0%): V 5.50 cu ft, with waste 5.50 cu ft — 10 80-lb bags, 13 60-lb bags; cement 0.86 cu ft (1 bag), lime 0.86 cu ft (1 bag), sand 5.16 cu ft. With no waste allowance the volume is exactly the base 5.50 cu ft — and one fewer 80-lb bag.
Waste 20%: V 5.50 cu ft, with waste 6.60 cu ft — 11 80-lb bags, 15 60-lb bags; cement 1.03 cu ft (2 bags), lime 1.03 cu ft (2 bags), sand 6.19 cu ft. At 20% waste the cement crosses 1.00 cu ft, so the bags go from 1 to 2.
Type M: cement 1.78 cu ft (2 bags), lime 0.44 cu ft (1 bag), sand 5.34 cu ft. Type M uses far more cement and far less lime than type N — that is what makes it 2,500 psi.
Type S: cement 1.26 cu ft (2 bags), lime 0.63 cu ft (1 bag), sand 5.67 cu ft. Type S sits between M and N: more cement than N, less than M.
Type O: cement 0.63 cu ft (1 bag), lime 1.26 cu ft (2 bags), sand 5.67 cu ft. Type O flips the balance — twice as much lime as cement — which is why it is only 350 psi and only for interior non-load-bearing walls.
Type K: cement 0.47 cu ft (1 bag), lime 1.42 cu ft (2 bags), sand 5.67 cu ft. Type K is mostly lime — 75 psi, soft enough not to damage old brick in historic restoration.
What the defaults assume
The model assumes standard brick (8 × 2-1/4 × 3-5/8 in) and standard concrete block (8 × 8 × 16 in), with the wall depth equal to the unit depth, and it uses the rounded rates in the table above — the rates are derived from first principles (wall volume minus unit volume per sq ft) and then rounded. It assumes the joint width and mortar type apply to the whole wall, and it does not model waste in the mix itself — the dry-mix allowance of ×1.25 covers the difference between the wet mortar in the wall and the dry ingredients you buy. With 0 sq ft the volume is 0.00 cu ft, the volume with waste is 0.00 cu ft and the bags are 0. With 100% waste the volume with waste is 11.00 cu ft, the 80-lb bags are 19, the 60-lb bags are 25, the cement is 1.72 cu ft (2 bags), the lime is 1.72 cu ft (2 bags) and the sand is 10.31 cu ft. At 500 sq ft the volume is 27.50 cu ft, the volume with waste is 30.25 cu ft and the bags are 51 and 68. Rounding convention: totals are computed from unrounded values, so rounded parts may differ by a cent from their rounded sum; the reverses are nearest-value solutions, and the exact unrounded figures (198.3471, 181.8182, 27.2727%, 111.5702, 176.3085, 247.9339) are stated wherever the rounded figures appear.
Output · formula · meaning
| Output | Formula | What it means |
|---|---|---|
| Mortar volume | wall area × rate for the unit and joint | 5.50 cu ft. |
| Volume with waste | volume × (1 + waste ÷ 100) | 6.05 cu ft. |
| 80-lb premix bags | ceil(volume with waste ÷ 0.6) | 11. |
| 60-lb premix bags | ceil(volume with waste ÷ 0.45) | 14. |
| Cement | volume with waste × cement share × 1.25 | 0.95 cu ft (1 bags). |
| Lime | volume with waste × lime share × 1.25 | 0.95 cu ft (1 bags). |
| Sand | volume with waste × sand share × 1.25 | 5.67 cu ft. |
| Area for 20x 80-lb bags | 12 ÷ (rate × (1 + waste ÷ 100)) | 198.3471 → 198.35 sq ft. |
| Area for V = 10.00 cu ft | 10 ÷ rate | 181.8182 → 181.82 sq ft. |
| Waste for Vw = 7.00 cu ft | (7 ÷ V − 1) × 100 | 27.2727% → 27.27%. |
| Area for 15x 60-lb bags | 6.75 ÷ (rate × (1 + waste ÷ 100)) | 111.5702 → 111.57 sq ft. |
| Area for sand 10.00 cu ft | 10 ÷ (rate × (1 + waste ÷ 100) × sand share × 1.25) | 176.3085 → 176.31 sq ft. |
| Area for 25x 80-lb bags | 15 ÷ (rate × (1 + waste ÷ 100)) | 247.9339 → 247.93 sq ft. |
| 200 sq ft | same model | V 11.00 cu ft, with waste 12.10 cu ft — 21x 80-lb bags, 27x 60-lb bags; cement 1.89 cu ft (2 bags), lime 1.89 cu ft (2 bags), sand 11.34 cu ft. |
| 500 sq ft | same model | V 27.50 cu ft, with waste 30.25 cu ft — 51x 80-lb bags, 68x 60-lb bags; cement 4.73 cu ft (5 bags), lime 4.73 cu ft (5 bags), sand 28.36 cu ft. |
| 50 sq ft | same model | V 2.75 cu ft, with waste 3.03 cu ft — 6x 80-lb bags, 7x 60-lb bags; cement 0.47 cu ft (1 bag), lime 0.47 cu ft (1 bag), sand 2.84 cu ft. |
| Joint 1/4 in | same model | V 3.80 cu ft, with waste 4.18 cu ft — 7x 80-lb bags, 10x 60-lb bags; cement 0.65 cu ft (1 bag), lime 0.65 cu ft (1 bag), sand 3.92 cu ft. |
| Joint 1/2 in | same model | V 6.90 cu ft, with waste 7.59 cu ft — 13x 80-lb bags, 17x 60-lb bags; cement 1.19 cu ft (2 bags), lime 1.19 cu ft (2 bags), sand 7.12 cu ft. |
| Block, 3/8 in joint | same model | V 4.40 cu ft, with waste 4.84 cu ft — 9x 80-lb bags, 11x 60-lb bags; cement 0.76 cu ft (1 bag), lime 0.76 cu ft (1 bag), sand 4.54 cu ft. |
| Block, 1/2 in joint | same model | V 5.80 cu ft, with waste 6.38 cu ft — 11x 80-lb bags, 15x 60-lb bags; cement 1.00 cu ft (1 bag), lime 1.00 cu ft (1 bag), sand 5.98 cu ft. |
| No waste (0%) | same model | V 5.50 cu ft, with waste 5.50 cu ft — 10x 80-lb bags, 13x 60-lb bags; cement 0.86 cu ft (1 bag), lime 0.86 cu ft (1 bag), sand 5.16 cu ft. |
| Waste 20% | same model | V 5.50 cu ft, with waste 6.60 cu ft — 11x 80-lb bags, 15x 60-lb bags; cement 1.03 cu ft (2 bags), lime 1.03 cu ft (2 bags), sand 6.19 cu ft. |
| Type M | same model | V 5.50 cu ft, with waste 6.05 cu ft — 11x 80-lb bags, 14x 60-lb bags; cement 1.78 cu ft (2 bags), lime 0.44 cu ft (1 bag), sand 5.34 cu ft. |
| Type S | same model | V 5.50 cu ft, with waste 6.05 cu ft — 11x 80-lb bags, 14x 60-lb bags; cement 1.26 cu ft (2 bags), lime 0.63 cu ft (1 bag), sand 5.67 cu ft. |
| Type O | same model | V 5.50 cu ft, with waste 6.05 cu ft — 11x 80-lb bags, 14x 60-lb bags; cement 0.63 cu ft (1 bag), lime 1.26 cu ft (2 bags), sand 5.67 cu ft. |
| Type K | same model | V 5.50 cu ft, with waste 6.05 cu ft — 11x 80-lb bags, 14x 60-lb bags; cement 0.47 cu ft (1 bag), lime 1.42 cu ft (2 bags), sand 5.67 cu ft. |
Who uses this
- The homeowner building a 100 sq ft garden wall: they learn the mortar is 5.50 cu ft and 6.05 cu ft with waste — 11 80-lb bags — and they check the 200 sq ft branch (12.10 cu ft, 21 bags) for the second wall.
- The mason mixing type M for a foundation: they learn type M needs 1.78 cu ft of cement and only 0.44 cu ft of lime — and they check the type S branch (1.26 cu ft of cement) to see how much weaker the next mix down is.
- The restorer repointing a historic wall: they learn type K is only 75 psi and mostly lime — 1.42 cu ft of lime against 0.47 cu ft of cement — and they check the type O branch to see why O is too strong for old brick.
- The contractor pricing a block wall: they learn a block wall at a 3/8 in joint needs only 4.40 cu ft per 100 sq ft — and they check the block 1/2 in branch (5.80 cu ft) to see what a wider joint costs.
Accuracy & limitations
The math is exact arithmetic on your five inputs, using the rounded rates in the table: V = area × rate; Vw = V × (1 + waste ÷ 100); 80-lb bags = ceil(Vw ÷ 0.6); 60-lb bags = ceil(Vw ÷ 0.45); cement = Vw × cement share × 1.25; lime = Vw × lime share × 1.25; sand = Vw × sand share × 1.25; cement bags = ceil(cement cu ft); lime bags = ceil(lime cu ft). The 4-decimal exact is shown where the rounding matters: the area for 20× 80-lb bags is 198.3471 sq ft (shown as 198.35 sq ft); at 198.34 sq ft it is 20 bags, at 198.35 sq ft it is 21. The area for V = 10.00 cu ft is 181.8182 sq ft (shown as 181.82 sq ft); at 181.81 sq ft V is 9.9996, at 181.82 sq ft it is 10.0001. The waste for Vw = 7.00 cu ft is 27.2727% (shown as 27.27%); at 27.27% Vw is 6.9999, at 27.28% it is 7.0004. The area for 15× 60-lb bags is 111.5702 sq ft (shown as 111.57 sq ft); at 111.57 sq ft it is 15 bags, at 111.58 sq ft it is 16. The area for sand 10.00 cu ft is 176.3085 sq ft (shown as 176.31 sq ft); at 176.30 sq ft sand is 9.9995, at 176.31 sq ft it is 10.0001. The area for 25× 80-lb bags is 247.9339 sq ft (shown as 247.93 sq ft); at 247.93 sq ft it is 25 bags, at 247.94 sq ft it is 26. What the model cannot do is measure your actual wall: real joints vary, bricks are not perfectly sized, and the waste allowance is your best guess — buy one extra bag for a big job and return it if you do not open it. The table values are theoretical, before waste. For the tile on the wall, see the tile size chart; for the slab underneath, see the concrete curing time chart; for the sanding between coats, see the sandpaper grit chart; for the paint over it, see the paint coverage chart; for the rebar in the slab, see the rebar size chart. This is a calculator, not a masonry guide.
Cite this calculatorBright Side Kit. “Mortar Mix Chart: Ratios, Strength & Bags Per Wall 2026” brightoolbox.com, 2026. Method: mortar types follow ASTM C270, parts by volume cement:lime:sand — M 1:0.25:3 (2,500 psi), S 1:0.5:4.5 (1,800 psi), N 1:1:6 (750 psi), O 1:2:9 (350 psi), K 1:3:12 (75 psi). Mortar volume per sq ft of wall (cu ft/sq ft) uses these rounded rates: brick 1/4 in 0.038, 3/8 in 0.055, 1/2 in 0.069, 5/8 in 0.083; block 1/4 in 0.030, 3/8 in 0.044, 1/2 in 0.058, 5/8 in 0.072. V = A × rate; Vw = V × (1 + w); 80-lb premix bags = ceil(Vw/0.6) (an 80-lb bag yields 0.6 cu ft); 60-lb bags = ceil(Vw/0.45); dry-mix allowance ×1.25 on component volumes; cement cu ft = Vw × a/(a+b+c) × 1.25; lime cu ft = Vw × b/(a+b+c) × 1.25; sand cu ft = Vw × c/(a+b+c) × 1.25; cement bags = ceil(cement cu ft) (a 94-lb bag is about 1 cu ft); lime bags = ceil(lime cu ft) (a 50-lb bag is about 1 cu ft). Key idea: the mortar type sets the strength — type N at 750 psi is the general-use mix, while type M at 2,500 psi is for below-grade work. Defaults: 100 sq ft brick wall, 3/8 in joint, type N, 10% waste → V 5.50 cu ft, Vw 6.05 cu ft, 11× 80-lb bags, 14× 60-lb bags, cement 0.95 cu ft / 1 bag, lime 0.95 cu ft / 1 bag, sand 5.67 cu ft. Branches: 200 sq ft → 11.00 / 12.10 / 21 / 27 / cem 1.89 (2) / lime 1.89 (2) / sand 11.34; 500 sq ft → 27.50 / 30.25 / 51 / 68 / cem 4.73 (5) / lime 4.73 (5) / sand 28.36; 50 sq ft → 2.75 / 3.03 (3.025) / 6 / 7 / cem 0.47 (1) / lime 0.47 (1) / sand 2.84; Joint 1/4 in → 3.80 / 4.18 / 7 / 10 / cem 0.65 (1) / lime 0.65 (1) / sand 3.92; Joint 1/2 in → 6.90 / 7.59 / 13 / 17 / cem 1.19 (2) / lime 1.19 (2) / sand 7.12; Block 3/8 in → 4.40 / 4.84 / 9 / 11 / cem 0.76 (1) / lime 0.76 (1) / sand 4.54; Block 1/2 in → 5.80 / 6.38 / 11 / 15 / cem 1.00 (1) / lime 1.00 (1) / sand 5.98; Waste 0% → 5.50 / 10 / 13 / cem 0.86 (1) / lime 0.86 (1) / sand 5.16; Waste 20% → 6.60 / 11 / 15 / cem 1.03 (2) / lime 1.03 (2) / sand 6.19; Type M → cem 1.78 (2), lime 0.44 (1), sand 5.34; Type S → cem 1.26 (2), lime 0.63 (1), sand 5.67; Type O → cem 0.63 (1), lime 1.26 (2), sand 5.67; Type K → cem 0.47 (1), lime 1.42 (2), sand 5.67. Reverses: area for 20× 80-lb bags = 198.35 sq ft (exact 198.3471; at 198.34 sq ft it is 20 bags, at 198.35 sq ft it is 21); area for V = 10.00 cu ft = 181.82 sq ft (exact 181.8182; at 181.81 sq ft V is 9.9996, at 181.82 sq ft it is 10.0001); waste for Vw = 7.00 cu ft = 27.27% (exact 27.2727%; at 27.27% Vw is 6.9999, at 27.28% it is 7.0004); area for 15× 60-lb bags = 111.57 sq ft (exact 111.5702; at 111.57 sq ft it is 15 bags, at 111.58 sq ft it is 16); area for sand 10.00 cu ft = 176.31 sq ft (exact 176.3085; at 176.30 sq ft sand is 9.9995, at 176.31 sq ft it is 10.0001); area for 25× 80-lb bags = 247.93 sq ft (exact 247.9339; at 247.93 sq ft it is 25 bags, at 247.94 sq ft it is 26). Edges: 0 sq ft → all 0, 0 bags; waste 100% → Vw 11.00, 19× 80-lb, 25× 60-lb, cem 1.72 (2), lime 1.72 (2), sand 10.31.
Bright Side Kit. "Mortar Mix Chart: Ratios, Strength & Bags Per Wall 2026" https://brightoolbox.com/mortar-mix-chart/ Accessed October 25, 2026.Frequently asked questions
How much mortar do I need for 100 sq ft of brick wall?
5.50 cu ft before waste, 6.05 cu ft with a 10% waste allowance — 11 bags (80 lb). A 100 sq ft brick wall with a 3/8 in joint and type N mortar needs 5.50 cu ft, and the cement is 0.95 cu ft (1 bag), the lime is 0.95 cu ft (1 bag) and the sand is 5.67 cu ft.
What is the difference between type M and type N mortar?
Strength — M is 2,500 psi, N is 750 psi. Type M is 1:0.25:3 (cement:lime:sand) and goes below grade; type N is 1:1:6 and is the general-use mix above grade. Type M needs 1.78 cu ft of cement per 100 sq ft against 0.95 cu ft for type N.
How many bags of mortar for a 500 sq ft wall?
51 bags (80 lb). At 500 sq ft of brick the volume is 27.50 cu ft and the volume with 10% waste is 30.25 cu ft — fifty-one 80-lb bags, or 68 60-lb bags. The sand alone is 28.36 cu ft.
What joint width uses the least mortar?
The narrowest — 1/4 in. A 1/4 in joint needs 3.80 cu ft per 100 sq ft of brick, against 5.50 cu ft at 3/8 in and 6.90 cu ft at 1/2 in. Wider joints take much more mortar.
Do block walls need less mortar than brick walls?
Yes, per square foot. A block wall at a 3/8 in joint needs 4.40 cu ft per 100 sq ft against 5.50 cu ft for brick — the blocks are bigger, so there are fewer joints. At a 1/2 in joint a block wall needs 5.80 cu ft.
What area gives exactly 20 bags of 80-lb mortar?
198.35 sq ft. At 198.34 sq ft it is 20 bags, at 198.35 sq ft it is 21 — so twenty 80-lb bags cover about 198 sq ft of brick wall at a 3/8 in joint.