How to tarp a roof?

What is a tarp actually for?

Two things, and neither is fixing the roof.

The first is stopping further water damage. Water entering a ceiling cavity does more expensive harm every hour — insulation, drywall, wiring, and eventually mould.

The second is your claim. Most homeowner policies place a duty on you to mitigate further damage after a loss. Tarping is the standard way of meeting it. Keep the receipt for the tarp and the fasteners; reasonable mitigation costs are frequently reimbursable, and this is one of the few parts of a claim that is genuinely straightforward.

When should I not do this myself?

Do not go up if any of these is true, and most of the time at least one will be:

• The roof is wet, icy, or has snow on it. Wet shingles are extraordinarily slippery, and this is the exact condition that exists right after the storm that damaged your roof.
• The roof is steeper than about 4:12, or you cannot tell what the pitch is.
• The damage is above the first storey.
• The deck is visibly damaged, sagging, or has a hole in it. If a tree hit your roof, the structure is compromised until an engineer or contractor says otherwise. Do not put your weight on it.
• It is still windy. A tarp is a sail, and holding one on a roof in wind is how people come off.

None of these is a judgement call to make optimistically at 6am with water coming through the ceiling. If you are unsure, the answer is no.

What do I do first, before anything else?

Document. From the ground, before anything is covered up.

Photograph the damage from several angles with a date visible. Photograph the interior — the ceiling stain, the wet insulation, anything damaged. Note the date and time the damage happened and keep the weather report for that day. If debris landed in the yard, photograph it where it fell.

An adjuster arriving after a tarp is in place is looking at a covered roof. Your photographs are the record of what was underneath it.

What can I do from inside instead?

Quite a lot, and none of it requires a ladder.

Move furniture and belongings out from under the leak. Put a bucket down. If a ceiling is bulging with trapped water, that water is heavy and the ceiling may come down all at once — the conventional advice is to relieve it deliberately with a small hole at the low point, standing to one side, with a container underneath. That is a genuinely difficult call to make and a soaked ceiling can be heavier than it looks.

Turn off electricity to any circuit where water is near a fixture or an outlet.

Photograph everything as you go.

How long does a tarp last?

Weeks, not months. Ultraviolet light degrades polyethylene tarps quickly, and the fasteners work loose in wind. A tarp that has been up for a season is doing very little.

Treat it as a countdown to a real repair, not an alternative to one. Insurers generally expect mitigation to be temporary and will not treat an indefinitely tarped roof as a resolved claim.

Does a tarp affect my insurance claim?

Failing to mitigate can hurt you. Mitigating helps you, provided you document what was there first.

What can genuinely damage your position is signing something. After a storm, contractors canvass door to door offering to tarp for free — sometimes attached to a contingency agreement that commits you to using them for the whole job at whatever the insurer approves. Read anything put in front of you, and do not sign before your own adjuster has been out. See what a contingency agreement actually commits you to.

Common mistakes

• Going up in the weather that caused the damage. The most dangerous roof conditions and the strongest urge to get on the roof arrive at exactly the same moment.
• Tarping before photographing. You have covered the evidence your claim depends on.
• Nailing the tarp through undamaged shingles. Every fastener is a new hole. Fasteners should land in the damaged area or in wood strips rolled into the tarp edge, and the whole thing has to come off and be repaired properly later regardless.
• Running the tarp only to the damage. Water runs downhill under shingles. A tarp needs to reach over the ridge or well above the damage, or water simply goes underneath it.
• Signing a contingency agreement to get a free tarp. A tarp costs perhaps sixty dollars. The agreement can commit you to a roof replacement.