After a home is damaged by fire, additional damage is likely to occurr when the fire is extinguished. If the property is not subsequently protected from the elements, the damage may continue to worsen. Proper initial analysis of structural damage to a house following a fire can help prevent unpleasant surprises later on.
Fire fighters may use thousands of gallons of water in the process of extinguishing a house fire. Once the fire is extinguished, the continued presence of water can cause damage to the structural elements of the home, may cause drywall to deteriorate, and can result in the development of mold.
It is thus important that, after a fire, any sitting water be removed from the home, and that the home be properly ventilated to facilitate the drying process. Wood framing elements and structural supports within a home are not likely to be damaged by exposure to water when the fire is extinguished, but prolonged exposure to water may cause damage such as warping or rot to occur.
Drywall and similar wall coverings should be removed in order to allow wet framing elements to dry and to help prevent the growth of mold within wall spaces. Insulation that has become wet should be removed, including insulation in ceilings, underfloor insulation and insulation that is contained within wall spaces.
If as a result of the fire or extinguishment of the fire, the home has broken windows or holes in the roof or walls, those openings should be covered in order to prevent additional damage to the home from exposure to rain or snow. While covering the openings may prolong the process of drying the interior of the home, it remains necessary to prevent the home from being exposed to addional moisture from precipitation.
Damage may occur to the home from the presence of wet floor coverings or other wet debris within the home. Wet carpet should be dried or removed. Piles of wet debris should be cleared from the home. Wet debris may not only cause damage by exposing the home to water, but by virtue of its weight. If left in place, wet debris can damage flooring, and may even damage floor joists and beams, increasing the cost and complexity of repair.
Although steel and masonry elements of a home are much more resistant to damage from fire and water than are wood elements, steel structural supports and masonry should be checked for damage. If the element is sheathed or enclosed, the encasement should be opened to ensure that there is no standing water inside the encasement. Proper drying of metal elements will prevent rust and corrosion.
If a steel support is damaged, any change in its geometry can affect its load-bearing capacity. Similarly, masonry elements such as brick or block walls and chimneys may be weakened by fire or exposure to water, and may require repair or replacement. It may be necessary to have damaged metal or masonry supports evaluated by a structural engineer.
Once the premises are dry, the premises should be checked for slope. If floors, structural elements or joists have become warped or sloped, they should be repaired or replaced before further repairs are performed. It may be possible to plane or shim the elements to render them sufficiently straight, plumb or level. Only after those repairs are complete, should new drywall, mouldings and floor coverings be installed.
If subflooring within the home to damage for a considerable period of time, it is good practice to replace those elements before performing additional repairs, as water damage and warping may cause problems when applying new roofing or floor coverings, and in achieving a cosmetically acceptable repair.
Similarly, if roof sheathing was exposed to water for a prolonged period of time, it is generally necessary to replace the sheathing. It is also necessary to remove and replace shingles and underlayment that were exposed to water, and which may otherwise prevent the roof sheathing from properly drying. If roof sheathing is wet but remains salvageable, the sheating should be tented with tarps in order to prevent additional exposure to moisture while it dries.