A tree limb goes through the deck at 9 p.m., or a storm strips a patch of shingles with more rain forecast by morning — this is the moment a roof tarp earns its keep. Emergency tarping is temporary weatherproofing that buys you weeks while you line up a proper repair, and doing it right matters twice over: a bad tarp job leaks anyway, and the most common installation shortcuts (nails through the ridge, bricks as anchors) create new damage that insurance may not cover. Here is how to pick the right tarp, secure it so it survives wind, and understand exactly how long it can protect you.
First: Safety and the Insurance Angle
Two things before any hardware:
- Do not climb onto a wet, damaged, or steep roof, or work in wind or lightning. Emergency tarping services exist ($300-$1,000 typical, often reimbursable) and no roof is worth a fall. If you go up: dry conditions, shoes with grip, a helper on the ground, and stay off any visibly sagging deck — a punctured deck may be structurally compromised.
- Your policy requires mitigation. Nearly every homeowner’s policy obligates you to prevent further damage after a loss; tarping is exactly that, and reasonable tarping costs are usually reimbursable. Photograph the damage thoroughly before covering it, keep receipts, and call your insurer’s claims line early — some carriers dispatch preferred tarping vendors at no upfront cost.
Choosing the Tarp: Size and Thickness
Thickness is measured in mils (thousandths of an inch), and the cheap blue tarp at the checkout end-cap is the wrong product:
| Tarp Class | Thickness | Cost (12×16 ft) | Realistic Roof Life |
|---|---|---|---|
| Light-duty blue poly | 5-6 mil | $10-$20 | Days to 2-3 weeks before UV and flapping shred it |
| Medium-duty poly (silver/brown) | 8-10 mil | $25-$45 | 1-2 months |
| Heavy-duty poly | 12-16 mil | $40-$80 | 2-6 months |
| Super-heavy / vinyl-coated | 18-23+ mil | $80-$200 | 6-12+ months (long insurance waits, post-hurricane) |
Buy 12 mil minimum for any roof application, UV-stabilized, with reinforced poly weave (look for weave counts of 14×14 per inch or better) and aluminum or heavy brass grommets every 18-24 in. Note that advertised tarp dimensions are cut size — finished size runs 3-6 in. smaller.
Sizing rule: the tarp must extend at least 4 ft beyond the damage on every side, and critically, it must run over the ridge and down the other slope by at least 4 ft. A tarp that ends above the damage on the same slope collects water at its top edge and funnels it straight into the hole. For a typical 6×6 ft damage patch mid-slope, that means a 20×30 ft tarp is normal. When in doubt, oversize — you can fold excess, you cannot stretch a short tarp.
The Right Way to Secure It: Batten Boards, Not Bricks
The professional method — and the one that survives wind — wraps the tarp edges around 2x4s and screws through wood, never relying on grommets alone or loose weights:
- Step 1 — Anchor board over the ridge. Roll the tarp’s top end around a 2×4 two or three full wraps (the board should be 2 ft longer than the tarp width), then position that board on the far slope, past the ridge, so the wrapped board hangs on the opposite side of the peak. Screw through the tarp-wrapped board into the roof with 3-in. deck screws every 16 in. Wrapping means the wind pulls against a full board and multiple fabric layers — not tearing at grommets.
- Step 2 — Stretch down the slope. Pull the tarp taut over the damage (lay a thin furring strip or foam across sharp deck edges first so the tarp does not chafe through) and past the eave if possible.
- Step 3 — Bottom board. Wrap the bottom edge around a second 2×4 and screw it either flat to the roof below the damage or — better — let it hang slightly over the eave edge and fasten into the fascia, which keeps water from tracking back under the tarp’s bottom edge.
- Step 4 — Side battens. Lay 2x4s (or 1×3 furring) along both side edges over the tarp and screw through into the roof every 16-24 in. Sides need not be wrapped, but they must be pinned continuously — flapping is what destroys tarps and works fasteners loose.
- Step 5 — Seal your own fasteners mentally. Every screw you drive is a future hole; keep them in the tarped field where the tarp itself covers them, note how many boards went on, and tell your roofer — those penetrations get repaired properly during the permanent fix. A dab of roofing cement on any fastener outside the tarp field is cheap insurance.
What not to do: no nails or screws through the ridge cap or ridge vent (you convert one leak into a ridgeline of leaks in the most water-exposed spot on the roof); no sandbags, bricks, or tires as the primary attachment (they slide, roll off in gusts, and become projectiles); no bungee-to-gutter rigging (gutters rip off); and no adhesive-only attachment on wet shingles.
Screw vs nail: screws, always — they hold in withdrawal far better under wind flutter and back out cleanly during repair.
Special Cases
- Damage at the eave or in a valley: run the tarp from over the ridge all the way past the eave; valleys need the tarp draped loosely enough to follow the fold, with battens on both planes.
- Steep roofs (8:12+): this is professional territory — harness work. Call a tarping service.
- Flat and low-slope roofs: tarps pond; use self-adhering membrane patches or peel-and-stick over the damage instead, with the tarp as a secondary layer sloped to drain — our flat roofing guide covers patch options.
- Shingle-less but intact deck (wind stripped shingles, no puncture): synthetic underlayment or peel-and-stick membrane fastened per its spec often beats a tarp — flatter, tighter, and it can stay under the eventual reroof.
How Long Can You Leave a Tarp On?
Plan in weeks, not seasons. A 12-16 mil tarp installed with batten boards typically protects reliably for 60-90 days; UV exposure, thermal cycling, and flutter degrade poly steadily, and southern sun cuts those numbers in half. Insurers commonly expect permanent repairs within 60-90 days of a claim, and some municipalities cite long-term blue roofs. Inspect after every storm: re-tension anything flapping, replace any tarp showing whitening, fraying, or grommet tears. If the wait for repair will exceed three months (post-hurricane contractor backlogs), install a super-heavy 20+ mil tarp or peel-and-stick membrane from the start rather than replacing failed light tarps twice. Then get the real fix scheduled — a tarp protects the hole; the water that entered before tarping still needs attic drying and inspection, and lingering leaks compound fast (see our roof repair guide for triaging the permanent work).
The Emergency Kit Worth Owning
In storm country, $120 on a shelf beats a midnight box-store run: one 20×30 ft 12-16 mil UV tarp, six 8-ft 2x4s (or a hand saw and knowing your lumber pile), 3-in. exterior screws and a charged driver, utility knife, and work gloves. Add a headlamp — these jobs never happen at noon.
FAQ
How much does professional roof tarping cost?
Typically $300-$1,000 depending on size, pitch, and urgency ($1,500+ post-disaster). Usually reimbursable under your claim — keep the invoice.
Will a tarped roof pass a storm?
A batten-board install with a ridge-wrapped anchor board survives ordinary storms and gusts of 40-60 mph. No tarp is hurricane-proof; re-check after every event.
Does insurance cover roof tarping?
Almost always, as damage mitigation — and failing to tarp can reduce coverage for the additional water damage that follows. Photograph first, tarp second, file promptly.
Oversize the tarp, run it over the ridge, wrap the boards, screw everything — and treat the tarp as a countdown timer, not a roof.
