Roof Replacement After a Fire

1. 1

   The scene is released and the investigation is done with the roof

   A fire scene belongs to the fire department until it releases it, and where a cause investigation is underway the building — including the roof structure — can be evidence. Removing material before an investigator is finished can destroy the record of what happened. Nobody demolishes anything until that is cleared.

2. 2

   A structural assessment exists in writing

   A licensed structural engineer determines what has lost capacity, what can stay, and what the repair details are. This is not a formality and it is not something a roofer, an adjuster or a general contractor can substitute for. On engineered trusses it goes further: a damaged truss is repaired to a detail from the truss designer or an engineer, not by nailing a sister to it.

3. 3

   Anything energised on the roof is dealt with by the right trade

   Photovoltaic arrays, rooftop equipment and service masts are not the roofer’s call. The array installer or a qualified electrician handles de-energising, removal and reinstatement, and the deck underneath cannot be examined until that has happened.

4. 4

   The mitigation plan is known before the roof is closed in

   Attic cleaning, insulation removal and duct work are far easier with the deck open. Deciding the roof scope without knowing the mitigation scope is how buildings get closed up over work that then has to be done through a hatch — see smoke odor in decking and attic insulation.

Strip away the arguing and the decision is four questions, answered in order. Only the first has a hard, external answer; the rest are judgement applied to physical facts.

• ●Is the framing adequate? The engineer’s question. Until it is answered, everything else is speculation, because framing repairs can require the deck off in areas the fire never reached.
• ●How much sheathing has lost section? Char has no structural value, so what matters is the sound wood beneath it — and, separately, how far outside the char the wood was heat-affected or water-damaged.
• ●Does the covering elsewhere still have a service life? Heat exposure that never charred anything can still have cost a slope its sealant bond and its granule cover. A roof can be structurally fine and still have no usable covering left.
• ●Will the repaired roof behave as one assembly? A patch has to tie into the existing underlayment, drainage and edge metal, be fastened to a deck with the same performance, and end up in the same plane. Where it cannot, the answer is a larger scope regardless of how small the burned area was.

The char boundary is not the repair boundary

The tempting rule is to cut out the charred sheets and put new ones in. The trouble is the zone just outside the char: wood that was heated enough to begin degrading without producing a visible char layer, and OSB whose adhesive was cooked and whose strands then swelled when the hose stream arrived. None of that reads clearly on a photograph, and none of it is a roofer’s determination. Where the deck is structural — and it always is for uplift, whatever else it is doing — the extent of removal comes from the assessment, not from where the black stops.

Mixing decks

Partial re-decking creates a roof of two materials and often two thicknesses. Panel thickness has to match the existing so the finished plane is flat, edge support at unsupported panel joints has to be provided the way the original assembly did it, and the new panels have to be fastened to the current requirement — which on a roof built decades ago is frequently a heavier nailing schedule than what is there. A deck that steps by even a fraction of an inch telegraphs through asphalt shingles in raking light for the life of the roof, and it is one of the most common complaints on partial fire repairs.

Old decks that cannot simply be patched

Plank and skip sheathing are the usual problem. Spaced boards are not a legal substrate for most modern coverings, they do not accept a self-adhered underlayment, and a fire repair that opens part of the roof frequently exposes a deck that will have to be sheathed over or replaced in full even where it was not damaged. The same applies to decks already carrying more than one layer of covering.

Fastening the field again

Deck nails lose withdrawal capacity in wood that has charred or swelled, and deck attachment is the foundation of the roof’s wind resistance. Re-nailing the existing field is routine on a fire repair, and in high-wind jurisdictions it may be required outright when the covering comes off. The FORTIFIED standard is a useful reference point for what an upgraded deck attachment and sealed deck actually consist of, since a fire repair is one of the few moments when the deck is accessible.

Fire damage is usually concentrated. The rest of the roof is the same age, the same product and the same weathering, which sets up the classic matching problem: a replacement section that is indistinguishable on paper and obvious from the street. Shingle colour blends drift between production runs, weathered material never matches new material, and products are discontinued on a shorter cycle than roofs last.

There are two separate questions inside this and they get conflated constantly. The construction question — can this be repaired so it reads as one roof? — is a roofer’s to answer, honestly and in advance, ideally with the owner standing in the driveway looking at a sample against the existing roof. The coverage question — what a policy owes when a repair cannot be matched — is not, and the answer varies by state, by policy wording and sometimes by regulation. There is no national rule, and anyone who states one without asking what state you are in is guessing. The discussion in why roof claims get denied or underpaid sets out why.

A roof repaired after a fire is work on an existing building, and existing-building rules are where the upgrades live. The relevant model document in most of the United States is the International Existing Building Code, which distinguishes repair from alteration and defines a threshold called substantial structural damage, above which more than a like-for-like restoration is required. It also contains provisions specifically for damage caused by loads the code does not design for — fire among them — that allow repair back to the pre-damage condition when the damage stays below defined limits. Those limits are numeric and they change between editions, so the number that matters is the one in the code your jurisdiction has adopted, as amended.

On a fire job the roofer is usually a subcontractor to a restoration general contractor, and the sequence is not the roofer’s to set. It is still worth understanding, because the arguments about it are predictable and the wrong order costs real money.

The pressure to get the roof on early is obvious: nothing inside can dry, and no finish can go in, under an open roof, and every week of temporary covering is a week of wind risk. The pressure the other way is that the deck being open is the cheapest access anybody will ever have to the attic — for structural repairs, for mechanical and electrical work, for insulation removal and for cleaning and sealing the deck underside and framing. Closing the roof first converts all of that into confined-space work through a hatch.

The order that generally survives contact with reality is: emergency protection and drying, then the investigation and structural assessment, then framing repairs, then attic mitigation and insulation removal, then decking and the new covering, then new insulation, then interior finishes. The corollary is that the roofer should be in the planning conversation early even though the roof work happens in the middle — which is the opposite of how a storm re-roof is scheduled. Temporary protection over an opened deck is the piece that holds the whole schedule together in the meantime.

On a storm claim the roof is the claim. On a fire claim it is one component of a scope that also covers framing, drywall, mechanical systems, contents, cleaning and often somewhere for the family to live. Three practical consequences follow.

• ●Someone else is usually holding the pen. The scope is typically assembled by the carrier’s adjuster and the restoration contractor’s estimator, frequently in Xactimate, and the roof arrives as line items inside it. A roofer who wants the roof scoped correctly has to get the detail into that document rather than issuing a separate proposal alongside it.
• ●Concealed damage is normal, and so are supplements. Nobody can see the deck until the covering is off or the attic until the insulation is out. Finding more than the original scope contemplated is the expected case on a fire job, not a sign that something went wrong. The claim process article explains how that mechanism works.
• ●Documentation has to be built as you go. Photograph the deck after tear-off, the framing after the covering is off, and the attic before anything is removed. Documenting roof damage for a claim covers the discipline; on a fire loss, add the engineer’s report and the fire department’s incident record to it.

• ●SmokeDamage.org on the smoke damage insurance claim — an independent walk through how a smoke claim is documented and evidenced, and what carriers commonly push back on. The claims-side counterpart to the construction decisions above.
• ●SmokeMitigation.com — smoke damage testing and mitigation — laboratory testing of attics, surfaces and HVAC with chain of custody, and remediation protocols written by industrial hygienists. Worth commissioning before the deck is closed in rather than after.
• ●SmokeHazard.com — indoor smoke exposure — the health-focused library on what is in smoke, what exposure means, and who in a household is most vulnerable. The reference for the re-occupancy question this article declines to answer.
• ●International Code Council — publisher of the International Existing Building Code and the residential code, and the place to confirm which editions exist before checking which one your jurisdiction adopted.