Alright—roofing a house is totally doable if you treat it like a serious job site: safety first, water-management always, follow the system, don’t freestyle. Below is a solid “asphalt shingle” playbook (most common in the U.S.). If you’re doing metal/tile, the flow is similar but details differ.

0) Decide if this is DIY or pro territory

Hire it out if any of these are true:

• Roof is steep (roughly 6/12+), 2+ stories, or you’re not comfortable on ladders
• There’s soft decking, sagging, rot, or structural weirdness
• You need major flashing work around chimneys/skylights/complex valleys

A roof is basically water engineering + gravity + consequences.

1) Plan + measure

• Measure roof area (square footage). Roofing is sold in “squares” = 100 sq ft.
• Order shingles + extras: typically ~10% waste, more if lots of hips/valleys.
• Check local permit/code requirements (often includes underlayment, ice/water, ventilation).

2) Tools + materials (typical shingle roof)

Safety

• Harness + roof anchor, rope/lanyard
• Roof jacks / planks (for footing), helmet/eye protection, non-slip shoes

Tools

• Roofing nailer (or hammer), utility knife with hook blades
• Flat pry bar, roofing shovel/tear-off spade
• Chalk line, tape measure, snips
• Caulk gun (roof sealant), magnetic nail sweeper

Materials

• Shingles (architectural is common)
• Starter strip shingles
• Drip edge (eave + rake metal)
• Underlayment (synthetic felt or felt)
• Ice & water shield (especially eaves/valleys; code may require)
• Flashing: step flashing, vent pipe boots, valley metal (if used)
• Ridge cap shingles + ridge vent (if vented)
• Roofing nails (correct length; typically long enough to penetrate decking)

3) Tear-off (if re-roofing)

1. Protect landscaping, set dumpster, tarp everything.
2. Strip shingles down to deck.
3. Pull old nails / clean surface.
4. Inspect decking:
   
   • Replace any soft/rotted OSB/plywood
   • Re-nail loose decking
6. Check for proper ventilation plan (intake soffit + exhaust ridge/vents).

4) Water-proofing layers (this is where roofs are won)

Order matters and overlaps matter.

A) Drip edge (often: eaves first)

• Install drip edge along eaves.
• Some systems put underlayment over eave drip edge, then rake drip edge over underlayment. Follow your local code + manufacturer system.

B) Ice & water shield

• Apply at eaves (typically from edge up past interior wall line), and in valleys.
• Roll it flat, no fishmouths, seal overlaps.

C) Underlayment

• Roll horizontal courses from bottom up.
• Overlap per product specs; keep it tight and smooth.
• Staple/cap-nail as required.

5) Flashing (non-negotiable)

• Valleys: either woven shingles, cut valley, or metal valley—pick one method and do it clean.
• Walls/chimneys: step flashing + counterflashing (chimneys are notorious leak zones).
• Pipes/vents: new boots; don’t reuse crusty ones.

If you mess up one thing, it’s usually flashing.

6) Shingles: layout + install

1. Snap chalk lines for straight rows.
2. Install starter strip along eaves (sticky edge toward eave).
3. First course of shingles goes on top of starter.
4. Work bottom-up, staggering joints (per shingle pattern).
5. Nail placement matters:
   
   • Nails in the manufacturer nail line
   • Correct count per shingle (often 4–6 depending on wind zone)
   • Keep nails flush (not overdriven, not proud)

7) Ridges + hips

• If using ridge vent: cut slot (leave ends uncut), install vent, then ridge caps.
• Install ridge cap shingles with correct overlap and nails long enough.

8) Sealing details + cleanup

• Seal exposed nail heads only where required (don’t “tar everything” randomly).
• Replace/paint flashings if needed.
• Clean gutters, run magnetic sweeper around house twice.
• Hose-test suspicious areas (gentle “rain simulation,” not a pressure washer attack).

Rookie mistakes that cause leaks

• Bad flashing at chimney/walls
• Wrong nail placement / overdriven nails
• Underlayment laps facing the wrong way (water can run under)
• Sloppy valleys
• Reusing old pipe boots
• No ventilation plan → cooks the roof from underneath

If you tell me 4 things, I’ll tailor this to your exact roof

1. Roof type: asphalt / metal / tile
2. Pitch: low / medium / steep (or “X/12” if you know it)
3. Location/climate: any snow/ice? strong winds?
4. Re-roof over existing or full tear-off?

And if you want the hardcore shortest version: Water flows downhill, overlaps are sacred, flashing is king, and gravity has no mercy.