- Asphalt shingles are not allowed below a 2/12 pitch. From 2/12 up to 4/12 they need two layers of underlayment (R905.2.2, R905.1.1).[1]
- A new layer of shingles may not go over a roof that already has two or more layers (R908.3.1.1). Heavy designer shingles weigh far more than standard ones, so ask whether the framing can carry them.[1][2]
- Above 21/12, shingles need the maker’s steep-slope method, usually hand sealing and often 6 nails or a lower nail line.[1][3]
- Roof work is fall-hazard work. The asphalt roofing manufacturers’ association tells homeowners to look at a roof from the ground with binoculars and not to climb on it.[4] Measure from the ground or the house plans, and leave the roof itself to people with fall protection.
- Shingle warranties depend on using the parts and methods in the maker’s instructions (starter, cap, underlayment, nailing). Read the instructions for the product you buy.
How the calculator counts
slope factor = √(1 + (pitch ÷ 12)²)
squares = roof area ÷ 100
shingle bundles = roof area × (1 + waste) ÷ coverage per bundle, rounded up
starter bundles = (eaves + rakes) ÷ length per bundle, rounded up
cap bundles = (ridges + hips) ÷ length per bundle, rounded up
drip edge pieces per edge = 1 + (edge − 10 ft) ÷ (10 ft − lap), rounded up; add up every eave and rake
A roofing square is 100 sq ft of roof surface.[5][2] Every plane of a roof that has one pitch is longer than its level footprint by the same factor, so the whole roof is its plan area times that factor, for a gable or a hip alike. CertainTeed and IKO print the same factors in their estimating tables.[2][6] Apply the pitch once, to the area. An IKO blog post says a 5/12 roof takes about 25% more shingles than its plan;[7] the factor at 5/12 is 1.083, or 8.3% more.
Example: a 6/12 gable roof (CertainTeed’s example)
The calculator opens on the gable roof worked in CertainTeed’s applicator manual, a 38 × 28 ft roof plan at 6/12.[2] It reproduces it as a house 36 ft long and 26 ft wide with 12 in overhangs all round.
- Plan area: 38 × 28 = 1,064 sq ft
- Slope factor at 6/12: √(1 + 0.5²) = 1.11803
- Roof area: 1,064 × 1.11803 = 1,189.59 sq ft, or 11.90 squares (CertainTeed rounds it to 1,190)
- Waste 10%: 1,189.59 × 1.10 = 1,308.55 sq ft
- Shingles at 98.4 sq ft per three bundles (32.8 sq ft each): 1,308.55 ÷ 32.8 = 39.89 → 40 bundles
- Eaves: 2 × 38 = 76 ft. Rakes: 4 × 14 ft of run × 1.11803 = 62.61 ft. Ridge: 38 ft
- Starter on eaves and rakes: 138.61 ft ÷ 105 ft per bundle → 2 bundles
- Ridge cap: 38 ft ÷ 25 ft per bundle → 2 bundles
- Synthetic underlayment: 1,189.59 ÷ 937 sq ft per roll → 2 rolls
- Drip edge: 2 eaves of 38.00 ft at 4 pieces each + 4 rakes of 15.65 ft at 2 each = 16 pieces (dividing the 138.61 ft total would give 15)
Example: a 5/12 hip roof
CertainTeed’s hip example is 44 × 22 ft in plan at 5/12; enter a 42 × 20 ft house with 12 in overhangs.[2] A hip roof has eaves on all four sides and no rakes. Its ridge is the length minus the width, and each of the four hips runs from a corner to the end of the ridge.
each hip = run × √(2 + (pitch ÷ 12)²), where run = plan width ÷ 2
- Roof area: 968 × 1.08333 = 1,048.67 sq ft (CertainTeed: 1,048)
- Hips: 11 × √(2 + (5 ÷ 12)²) = 16.22 ft each, 64.87 ft for four. CertainTeed gets 16.21 ft each from its rounded table factor of 1.474.
- Ridge: 44 − 22 = 22 ft, so cap covers 86.87 ft → 4 bundles of a 25 ft cap. Eaves: 2 × (44 + 22) = 132 ft
- Waste 15% for a hip: 1,048.67 × 1.15 = 1,205.97 sq ft ÷ 32.8 = 36.77 → 37 bundles
Measuring without climbing
- Length and width: measure the outside of the walls at ground level, or take them from the plans. On a hip roof the calculator runs the ridge along the longer side.
- Overhangs: measure level from the wall to the outer edge of the roof, under the eave and at a gable end.
- Pitch: measure it from the attic with a level against a rafter; the roof pitch calculator shows how. The same page has the full pitch chart.
- Dormers, wings and valleys: work each roof section separately and add them, or switch to “Roof area I already know” and use the figures from a measurement report or the plans.
For reference, here are the formula’s slope factors next to the tables CertainTeed and IKO publish (the two tables are identical):[2][6]
| Pitch | Area and rake factor | CertainTeed / IKO | Hip and valley factor | CertainTeed / IKO |
|---|---|---|---|---|
| 4/12 | 1.0541 | 1.054 | 1.4530 | 1.452 |
| 5/12 | 1.0833 | 1.083 | 1.4743 | 1.474 |
| 6/12 | 1.1180 | 1.118 | 1.5000 | 1.500 |
| 7/12 | 1.1577 | 1.157 | 1.5298 | 1.524 |
| 8/12 | 1.2019 | 1.202 | 1.5635 | 1.564 |
| 9/12 | 1.2500 | 1.250 | 1.6008 | 1.600 |
| 10/12 | 1.3017 | 1.302 | 1.6415 | 1.642 |
| 11/12 | 1.3566 | 1.356 | 1.6853 | 1.684 |
| 12/12 | 1.4142 | 1.414 | 1.7321 | 1.732 |
The area factors are all within 0.001 of the formula. The hip and valley factors are within 0.002 of it, except at 7/12, where both tables print 1.524 and the formula gives 1.530. The calculator uses the formula, so it also handles pitches the tables leave out.
Bundles: why three is not always 100 sq ft
Most shingles are sold three bundles to a square, but a square of shingles does not always cover 100 sq ft. GAF’s Timberline HDZ, Owens Corning’s Duration and TAMKO’s Heritage all state 98.4 sq ft for three bundles.[8][9][10] You can check any wrapper: coverage = shingles × length × exposure ÷ 144.
| Shingle | Shingles per square | Length × exposure | Maker’s coverage | Shingles × length × exposure ÷ 144 |
|---|---|---|---|---|
| GAF Timberline HDZ[8] | 64 | 39⅜ × 5⅝ in | 98.4 sq ft | 98.44 sq ft |
| Owens Corning TruDefinition Duration[9] | 64 | 39⅜ × 5⅝ in | 98.4 sq ft | 98.44 sq ft |
| TAMKO Heritage[10] | 64 | 5⅝ in exposure | 98.4 sq ft | — |
| CertainTeed Landmark[11][12] | 66 | 38¾ × 5⅝ in | — | 99.90 sq ft |
| IKO Cambridge[13] | 60 | 40⅞ × 5⅞ in | 100 sq ft | 100.06 sq ft |
| CertainTeed XT 25 (3-tab)[14][12] | 80 | 36 × 5 in | — | 100.00 sq ft |
| GAF Royal Sovereign, 12 × 36 in (3-tab)[15] | 79 | 36 × 5 in | — | 98.75 sq ft |
The calculator uses the coverage of the shingle you pick. Its default is the 98.4 sq ft square, 32.8 sq ft per bundle. Dividing by 100 instead comes up short as the roof gets bigger:
| Roof area | With 10% waste | Bundles at 98.4 sq ft per square | Bundles at 100 sq ft per square |
|---|---|---|---|
| 1,000 sq ft | 1,100 sq ft | 34 | 33 |
| 1,500 sq ft | 1,650 sq ft | 51 | 50 |
| 2,000 sq ft | 2,200 sq ft | 68 | 66 |
| 2,500 sq ft | 2,750 sq ft | 84 | 83 |
| 3,000 sq ft | 3,300 sq ft | 101 | 99 |
Heavier shingles come 4 to 6 bundles to a square
Some shingles, mostly thick designer and shake-look lines, come in more bundles per square. ARMA gives 3 to 5 bundles per square for laminated shingles and 3 to 4 for strip shingles.[5] Four per square: GAF Camelot II, Grand Sequoia AS, CertainTeed NorthGate and Belmont, Malarkey Legacy. Five: GAF Grand Sequoia, CertainTeed Grand Manor, Carriage House and Presidential Shake, Malarkey Windsor, IKO Armourshake. Six: CertainTeed Presidential Shake TL and Owens Corning Woodcrest.[16][17][12][18][19][20][21] For these, pick “Other” and enter the coverage per bundle from the wrapper: IKO packs Armourshake at 20 sq ft per bundle, for example.[20]
Shingles by house size and pitch
Gable roof, 12 in overhangs, 10% waste, 98.4 sq ft per three bundles. Each cell is roof area, then bundles. A hip roof on the same house has the same area but takes 15% waste instead of 10%.
| House (outside walls) | 4/12 | 6/12 | 8/12 | 10/12 | 12/12 |
|---|---|---|---|---|---|
| 24 × 36 ft | 1,041 sq ft 35 bundles | 1,105 sq ft 38 bundles | 1,187 sq ft 40 bundles | 1,286 sq ft 44 bundles | 1,397 sq ft 47 bundles |
| 26 × 40 ft | 1,240 sq ft 42 bundles | 1,315 sq ft 45 bundles | 1,413 sq ft 48 bundles | 1,531 sq ft 52 bundles | 1,663 sq ft 56 bundles |
| 28 × 44 ft | 1,455 sq ft 49 bundles | 1,543 sq ft 52 bundles | 1,659 sq ft 56 bundles | 1,796 sq ft 61 bundles | 1,952 sq ft 66 bundles |
| 30 × 50 ft | 1,754 sq ft 59 bundles | 1,860 sq ft 63 bundles | 2,000 sq ft 68 bundles | 2,166 sq ft 73 bundles | 2,353 sq ft 79 bundles |
| 32 × 60 ft | 2,222 sq ft 75 bundles | 2,357 sq ft 80 bundles | 2,534 sq ft 85 bundles | 2,744 sq ft 93 bundles | 2,981 sq ft 100 bundles |
| 40 × 60 ft | 2,745 sq ft 93 bundles | 2,911 sq ft 98 bundles | 3,130 sq ft 105 bundles | 3,390 sq ft 114 bundles | 3,683 sq ft 124 bundles |
Waste
Left blank, the waste is 10% on a gable roof and 15% on a hip roof, CertainTeed’s general practice. CertainTeed adds that this is too much on large roofs, and gives a table by roof area:[2]
| Roof area | Gable waste | Bundles: table / 10% | Hip waste | Bundles: table / 15% |
|---|---|---|---|---|
| 600 sq ft | 8% | 20 / 21 | 17% | 22 / 22 |
| 1,200 sq ft | 6% | 39 / 41 | 13% | 42 / 43 |
| 1,500 sq ft | 5% | 49 / 51 | 11% | 51 / 53 |
| 2,000 sq ft | 4% | 64 / 68 | 9% | 67 / 71 |
| 3,200 sq ft | 3% | 101 / 108 | 8% | 106 / 113 |
Other sources give ranges: ARMA 2% to 10%, IKO 10% to 15%, GAF up to 10%.[5][20][22] The calculator’s hint of about 20% for roofs with many valleys and dormers is our rough figure; no maker we checked publishes one. The waste goes on the field shingles only. Starter, cap and drip edge are counted from their own lengths, as in CertainTeed’s example, which also tells you to order one extra square per job for bundles damaged in handling.[2]
Starter strip
Starter goes along every eave; CertainTeed counts it as the eave length divided by the starter’s length per bundle.[2][8] The rakes are where makers differ. GAF recommends starter on the rakes and requires it for its enhanced warranties; Owens Corning’s 160 mph wind coverage on Duration needs starter on both eaves and rakes; CertainTeed’s drawing for Highland Slate and Atlas’s starter drawing mark the rake starter as optional.[8][9][2][23] The calculator includes the rakes by default. On a rake, lap the starter over the eave starter by at least 3 in, and let starter overhang the edges by ¼ to ¾ in.[24]
| Starter | Per bundle | Gable example, eaves and rakes (138.6 ft) | Eaves only (76 ft) | Hip example (132 ft) |
|---|---|---|---|---|
| Owens Corning Starter Strip Plus | 105 ft | 2 | 1 | 2 |
| GAF Pro-Start | 120.33 ft | 2 | 1 | 2 |
| CertainTeed SwiftStart | 116 ft | 2 | 1 | 2 |
| IKO Leading Edge Plus | 109 ft | 2 | 1 | 2 |
| Malarkey Smart Start | 114.75 ft | 2 | 1 | 2 |
| Atlas Pro-Cut HP42 | 140 ft | 1 | 1 | 1 |
Lengths from each maker’s sheet.[25][26][27][28][18][23] When you don’t know the brand yet, keep the shortest, 105 ft.
Hip and ridge cap
Cap bundles run from 20 to 33 ft among the caps in the calculator, so pick the cap that goes with your shingle.
| Cap | Per bundle | Gable example (38 ft) | Hip example (86.9 ft) |
|---|---|---|---|
| GAF Seal-A-Ridge | 25 ft | 2 | 4 |
| GAF TimberTex or OC DecoRidge | 20 ft | 2 | 5 |
| Owens Corning ProEdge | 33 ft | 2 | 3 |
| CertainTeed Shadow Ridge | 30 ft | 2 | 3 |
| IKO Hip & Ridge 12 | 29.53 ft | 2 | 3 |
| Malarkey RidgeFlex 12 in | 30.92 ft | 2 | 3 |
Lengths from each maker’s sheet.[29][30][31][32][33][34][18] CertainTeed’s Shadow Ridge comes in 30 ft bundles in English size and 45 ft in metric size, depending on the region.[33] If you cut caps from 3-tab shingles instead, CertainTeed allows 1 sq ft of shingle per foot of hip and ridge.[2]
Underlayment
Rolls are sold by gross area, but laps use some of it. The calculator divides by the area a roll covers once it is lapped.
| Underlayment | Covers, lapped | Rolls, gable example at 6/12 (1,190 sq ft) | Same house at 3/12, two layers (1,097 sq ft) |
|---|---|---|---|
| Synthetic, 10-square roll[35][36] | 937 sq ft | 2 | 3 |
| #15 felt, 4-square roll[37] | 408 sq ft | 3 | 6 |
| #30 felt, 2-square roll[37] | 204 sq ft | 6 | 11 |
- Felt: a #15 roll is 36 in × 144 ft (432 sq ft, sold as “4 squares”) and a #30 roll 36 in × 72 ft (216 sq ft, “2 squares”); TAMKO rates them at 408 and 204 sq ft as installed.[37]
- Synthetic: rolls are sold as 10 squares. GAF’s 1,000 sq ft excludes laps; Owens Corning rates Deck Defense at 937 sq ft with 3 in laps, CertainTeed RoofRunner at 937.5.[38][35][36]
- 4/12 and steeper: one layer, side laps 2 in, end laps 4 in staggered 6 ft under the IRC; GAF’s FeltBuster synthetic asks for 3 in and 6 in.[1][39]
- 2/12 up to 4/12: two layers. The IRC starts with a 19 in strip at the eave, then laps 36 in sheets 19 in, leaving 17 in exposed, so the felt on the roof adds up to 36 ÷ 17 = 2.12 times the roof area.[1] GAF lays synthetic at a 22.5 in exposure on low slopes, 48 ÷ 22.5 = 2.13 times.[39] The roll coverage the calculator uses already allows for single-layer laps (34 in of each 36 in course exposed for felt, 45 of 48 in for synthetic), so against that coverage two layers take exactly 2 times as much: 34 ÷ 17 and 45 ÷ 22.5. At 3/12 the example house needs 3 synthetic rolls or 6 rolls of #15 felt. Instead of two layers, the IRC also accepts one layer of self-adhering underlayment (ASTM D1970) over the whole deck, and Malarkey lists the same option; the calculator does not count that case. It also leaves out the 19 in starter strip the IRC lays at the eave first, which adds a little felt.[1][40]
Ice barrier
The IRC requires an ice barrier only where your jurisdiction has a history of ice forming at the eaves (R905.1.2). Where it applies, it runs from the eave to at least 24 in inside the exterior wall line, and on roofs of 8/12 and steeper also at least 36 in measured along the slope.[1] ARMA, CertainTeed, GAF and Owens Corning’s Duration instructions go farther: 24 in past the interior wall line.[41][2][8][42] The calculator uses the makers’ line, the more cautious of the two (one Owens Corning sheet uses the exterior wall).[43]
courses = 1 + (width − 36 in) ÷ (36 in − 3 in lap), rounded up
Rolls are counted at 200 sq ft and 36 in wide (GAF StormGuard). The 6 in end laps between rolls are not added, and some rolls are smaller (CertainTeed WinterGuard is 195 sq ft), so on a long eave round up by a roll.[44][45]
On the example house with 6 in walls: (12 + 6 + 24) × 1.1180 = 47.0 in, more than one 36 in width, so 2 courses along 76 ft of eave: 152 ft × 3 ft ÷ 200 sq ft = 2.28 → 3 rolls. At 8/12 the width grows to 50.5 in, still 2 courses. Rolls are 200 sq ft (36 in × 66.7 ft) for GAF StormGuard and 195 sq ft for CertainTeed WinterGuard; side laps are 3 to 6 in by product.[44][45][43] Valleys are not included.
Drip edge
The IRC calls for drip edge at both eaves and rakes, lapped at least 2 in, reaching ¼ in below the sheathing and 2 in onto the deck, nailed at most 12 in apart; underlayment goes over it at the eaves and under it at the rakes (R905.2.8.5).[1] It is sold in 10 ft pieces.[2][46] Each eave and rake is its own run, so the calculator counts edge by edge: the example’s 138.6 ft takes 16 pieces with 2 in laps (dividing the total by one run would give 15, which is a piece short), and 16 with the 3 in laps Gibraltar recommends.[46] CertainTeed’s own example suggests buying 14 pieces for 121.6 ft, where dividing the total gives 13.[2] When you give the roof area instead of the building size, the calculator does not know the separate edges and counts all the eaves and all the rakes as one run each, so add a piece or two.
Nails
The IRC asks for at least four nails per strip shingle, or more if the maker says so, with a 12-gauge shank, a ⅜ in head and enough length to go ¾ in into the sheathing or through it (R905.2.5, R905.2.6).[1] Makers use 4 nails as standard. GAF calls for 6 where local code or an enhanced wind warranty requires it, and CertainTeed’s high-wind method uses 6.[8][2] Above 21/12, Owens Corning and Malarkey call for 6 nails plus hand sealing, and IKO lists 6 nails for steep slopes.[42][40][13]
The count is shingles × nails per shingle. GAF lists 256 nails per square for Timberline HDZ (64 × 4).[47] That square covers 98.4 sq ft, so 256 × 13.09 squares of roof and waste (3,350) runs short. The calculator counts shingles instead: 39.89 bundles × 21.33 shingles × 4 = about 3,405. Starter and cap take more on top.
Tear-off weight
For the dumpster, the calculator uses about 230 lb per square for each layer. That is our estimate: CertainTeed rates Landmark at 217 to 229 lb per square and XT 25 3-tab at 190 to 203,[11][14] and ARMA’s industry average of 10.6 kg/m² for shingles alone is 217 lb per square, 242 with the underlayment and other parts.[48] It is the top of CertainTeed’s range rounded up, so treat the result as approximate. The calculator uses it for every shingle; heavy shingles weigh much more (CertainTeed Grand Manor 430 lb, Carriage House 350 lb per square), so for those use the maker’s weight.[2] Two layers on the gable example come to 5,472 lb, about 2.74 tons. With two layers already on, the IRC does not allow a third, so the old roof comes off.[1]
What the calculator does not count
- Valley lining: at least 24 in wide for open-valley metal, 36 in for closed-valley roll roofing (R905.2.8.2).[1]
- Step and wall flashing, at least 4 in by 4 in (R905.2.8.3), and a cricket behind a chimney more than 30 in wide (R903.2.2).[1]
- Vents, pipe boots, replacement sheathing, and nails for starter and cap.
- Rafters and framing: see the rafter length calculator.
Questions people ask
How do I calculate how much shingles I need?
Multiply the plan area including overhangs by the slope factor √(1 + (pitch ÷ 12)²), add 10% waste for a gable or 15% for a hip, and divide by the coverage per bundle on the wrapper. A 38 × 28 ft plan at 6/12 is 1,190 sq ft, 1,309 sq ft with waste, and 40 bundles at 32.8 sq ft each.
How many bundles of shingles do I need for 100 square feet?
Three bundles if they cover 100 sq ft; but for shingles that cover 98.4 sq ft per three bundles, 100 ÷ 32.8 = 3.05, so 4. With 10% waste it is 4 either way.
How many sq ft does 1 sq of shingles cover?
A roofing square is 100 sq ft by definition. A square of shingles, as packaged, covers what the wrapper says: 98.4 sq ft for GAF Timberline HDZ, Owens Corning Duration and TAMKO Heritage, 100 sq ft for IKO Cambridge.
How many bundles of shingles for a 2000 sq ft roof?
With 10% waste, 68 bundles of shingles that cover 98.4 sq ft per square, or 66 of shingles that cover 100 sq ft. That is for 2,000 sq ft of roof surface, not floor area.
How many squares of shingles do I need for a 2000 sq ft house?
It depends on the footprint and pitch, not the floor area. A one-story 40 × 50 ft house with 12 in overhangs and a 6/12 gable roof has 2,442 sq ft of roof, 24.42 squares, and needs 82 bundles with waste. A two-story house with 1,000 sq ft per floor (25 × 40 ft) has about half that roof: 1,268 sq ft and 43 bundles.
How much do 5 bundles of shingles cover?
About 164 sq ft for shingles sold at 98.4 sq ft per three bundles, or 167 sq ft for 100 sq ft per three. For heavy shingles packed five bundles to a square, such as GAF Grand Sequoia, five bundles make one square.
Related calculators
Sources
- International Code Council, 2021 International Residential Code, Chapter 9 Roof Assemblies. R905.1.1 underlayment, R905.1.2 ice barrier, R905.2.2 slope, R905.2.5–R905.2.6 fasteners, R905.2.8 flashing and drip edge, R908.3.1.1 recovering. Checked 2026-10-05.
- CertainTeed, Master Craftsman Shingle Applicator’s Manual, 17th edition (13-03-5418). Square of 100 sq ft; slope and hip/valley factor tables; waste 10% gable, 15% hip and Table 4 by roof area; drip edge sold in 10 ft lengths; ice barrier 24 in past the interior wall line; Grand Manor 430 and Carriage House 350 lb per square. Checked 2026-10-05.
- Asphalt Roofing Manufacturers Association (ARMA), Technical Bulletin: Application of Asphalt Shingles on Slopes Greater Than 21:12 (rev. May 2017). 21:12 is the steepest slope for normal application; steeper roofs need hand sealing (four spots of cement under laminated shingles). Checked 2026-10-05.
- Asphalt Roofing Manufacturers Association (ARMA), Frequently Asked Questions. Inspect the roof from the ground with binoculars: “DO NOT CLIMB ON THE ROOF; walking on the roof is dangerous and can damage your roof”. Checked 2026-10-05.
- Asphalt Roofing Manufacturers Association (ARMA), Residential Asphalt Roofing Manual, Design and Application Methods, 2014 Edition. 1 square = 100 sq ft; laminated shingles 3–5 bundles per square, strip shingles 3–4; 2% to 10% excess shingles; ice barrier to 24 in inside the interior wall line; four nails per shingle. Checked 2026-10-05.
- IKO, Estimating How Much Roofing Is Required. Area/rake and hip/valley conversion tables (same values as CertainTeed); 10% waste in the example. Checked 2026-10-05.
- IKO, How to Bid a Roofing Job (blog). Says a 5/12 roof uses roughly 25 percent more shingles than its plan area. Checked 2026-10-05.
- GAF, Installation Instructions: Timberline HDZ and related shingles (RESTL622). Three bundles cover 98.4 sq ft; starter at the rakes recommended and required for enhanced warranty coverage; leak barrier 24 in beyond the inside wall line; 4 nails standard, 6 enhanced; slopes of 2:12 or greater. Checked 2026-10-05.
- Owens Corning, TruDefinition Duration Shingles product page. 3 bundles, 64 shingles and 98.4 sq ft per square; 160 mph wind coverage with starter on both eaves and rakes. Checked 2026-10-05.
- TAMKO (copy hosted by BuildSite), Heritage product data. 3 bundles and 64 shingles per sales square; one sales square covers 98.4 sq ft. Checked 2026-10-05.
- CertainTeed (copy hosted by the RCABC Roofing Practices Manual), Landmark Shingles technical data sheet. 66 shingles per square, 13¼ × 38¾ in, 5⅝ in exposure; 217 to 229 lb per square. Checked 2026-10-05.
- CertainTeed, Roofing Selection Guide (00-00-253-US-EN). Bundles per square by product (Landmark and XT 25 3; NorthGate and Belmont 4; Grand Manor, Carriage House and Presidential Shake 5; Presidential Shake TL 6). Checked 2026-10-05.
- IKO, Cambridge technical data sheet (04/2026). 20 shingles and 33.3 sq ft per bundle, 100 sq ft per three bundles; 40⅞ × 13¾ in, 5⅞ in exposure; 4 nails standard, 6 on steep slopes. Checked 2026-10-05.
- CertainTeed, XT 25 Shingles technical data sheet (CTRCOMM-015). 80 shingles per square, 5 in exposure; 190–203 lb per square. Checked 2026-10-05.
- GAF, Royal Sovereign Shingles product information sheet (English size). 12 × 36 in, 79 pieces per square, 5 in exposure; 316 nails per square (474 with 6 nails per shingle). Checked 2026-10-05.
- GAF, Camelot II Shingles product page. 4 bundles and 56 pieces per square. Checked 2026-10-05.
- GAF, Grand Sequoia AS Shingles data sheet (RESGN467GSAS). 4 bundles and 72 pieces per square. Checked 2026-10-05.
- Malarkey Roofing Products, Product Data Guide (rev. 08/26). Legacy 4 and Windsor 5 bundles per square; Smart Start 114 ft 9 in per bundle; 12 in RidgeFlex 30 ft 11 in per bundle. Checked 2026-10-05.
- GAF, Grand Sequoia Shingles product page. 5 bundles and 72 pieces per square. Checked 2026-10-05.
- IKO, How Many Square Feet in a Bundle of Shingles (blog). Armourshake 20 sq ft per bundle, five bundles per square; about 10–15% waste. Checked 2026-10-05.
- Owens Corning, Woodcrest Shingles product page. 6 bundles per square, 4 in exposure. Checked 2026-10-05.
- GAF, How to Measure a Roofing Square (blog). Consider adding up to 10% in overage. Checked 2026-10-05.
- Atlas Roofing, Pro-Cut HP42 Starter Shingles product data sheet. 140 lineal ft per bundle; drawing marks rake-edge use as optional. Checked 2026-10-05.
- GAF, Pro-Start installation instructions (RESGN853). Overhang eaves and rakes 1/4 to 3/4 in; rake starter overlaps the eave starter at least 3 in. Checked 2026-10-05.
- Owens Corning, Starter Strip Plus product page. About 105 lineal ft per bundle. Checked 2026-10-05.
- GAF, Pro-Start Starter Strip Shingles sell sheet (RESGN546). About 120.33 lineal ft per bundle. Checked 2026-10-05.
- CertainTeed, SwiftStart starter product page. Each 18-piece bundle covers 116 linear ft. Checked 2026-10-05.
- IKO, Leading Edge Plus technical data sheet (04/2026). 109 linear ft per bundle. Checked 2026-10-05.
- GAF, Seal-A-Ridge Ridge Cap Shingles sell sheet (RESHR112). 4 bundles cover 100 linear ft. Checked 2026-10-05.
- GAF, TimberTex Premium Ridge Cap Shingles sell sheet (RESHR102). 20 linear ft per bundle. Checked 2026-10-05.
- Owens Corning, DecoRidge Hip & Ridge Shingles product page. 20 lineal ft per carton. Checked 2026-10-05.
- Owens Corning, ProEdge Hip & Ridge Shingle data sheet. 33 lineal ft per bundle. Checked 2026-10-05.
- CertainTeed, Shadow Ridge technical data sheet. 30 lin ft per bundle (English size), 45 lin ft (metric size). Checked 2026-10-05.
- IKO, Hip & Ridge 12 technical data sheet (04/2026). 29.53 linear ft per bundle. Checked 2026-10-05.
- Owens Corning, Deck Defense roof underlayment product page. 10-square roll, 48 in × 250 ft; coverage with 3 in overlap 937 sq ft. Checked 2026-10-05.
- CertainTeed, RoofRunner synthetic underlayment sell sheet (00-04-2102). Roll 1,000 sq ft, 48 in × 250 ft; coverage 937.5 sq ft. Checked 2026-10-05.
- TAMKO, TAMKO Underlayments Brochure. No. 15 felt 36 in × 144 ft, 408 sq ft; No. 30 felt 36 in × 72 ft, 204 sq ft, when applied according to instructions. Checked 2026-10-05.
- GAF, Tiger Paw Premium Roof Deck Protection sell sheet (RESUL179). Roll size 10 squares (1,000 sq ft), excludes laps. Checked 2026-10-05.
- GAF, Installation Instructions for FeltBuster synthetic roofing felt. 3 in side laps, 6 in end laps; on low slopes, courses laid at a 22.5 in exposure. Checked 2026-10-05.
- Malarkey Roofing Products, Vista technical data sheet. Not on slopes under 2:12; over 21 in per foot, hand sealing and six nails. Checked 2026-10-05.
- Asphalt Roofing Manufacturers Association (ARMA), Protecting Against Damage from Ice Dams. Ice dam protection extended at least 24 in inside the interior wall line. Checked 2026-10-05.
- Owens Corning, Duration Series Shingles Installation Instructions. Ice and water barrier at least 24 in from the interior wall line; over 21 in per foot, 6 fasteners and 4 spots of roof cement. Checked 2026-10-05.
- Owens Corning, WeatherLock Granulated Ice & Water Barrier Installation Instructions. To 24 in inside the exterior wall, measured horizontally; 3 in side laps, 6 in end laps. Checked 2026-10-05.
- GAF, StormGuard Film-Surfaced Leak Barrier data sheet (RESUL116). Roll 2 squares (200 sq ft), 36 in × 66.7 ft, excludes laps. Checked 2026-10-05.
- CertainTeed, WinterGuard technical data sheet (CTRCOMM-015-2405). Roll area 195 sq ft (3 × 65 ft); side laps 3 to 6 in by product, end laps 6 in. Checked 2026-10-05.
- Gibraltar Building Products, Help center: Do the edges of the 10 ft. aluminum eave drip flashing overlap?. 10 ft pieces; a minimum end overlap of 3 in is recommended. Checked 2026-10-05.
- GAF, Timberline HDZ Shingles product page. 3 bundles and 256 nails per square. Checked 2026-10-05.
- Asphalt Roofing Manufacturers Association (ARMA), Environmental Product Declaration: Asphalt Shingle Roofing System Installation, Fastened (industry average). Shingles 10.6 kg/m²; whole installed system 11.8 kg/m². Checked 2026-10-05.