Every cut on a fallen tree moves its weight, so on a house the pieces come off in order.

The crew's storm advisory, written for a tree landing on a house, ends with a line that belongs ahead of everything here: "Please exercise caution and avoid walking near down power lines or parking vehicles under sagging trees." New York's Department of Health says twisted and bent branches and trees "are usually under strain that is undetectable to the untrained eye."

What to do before anyone arrives is in the first-hour steps for the household; the line answered around the clock is on the 24-hour emergency tree service page.

A tree that lands on a house is propped on whatever it hit. New Jersey's FACE program wrote that "Fallen trees are frequently under tension and compression forces (on opposite sides) depending on the way they are supported by the ground or their limbs." The compression side "is being squeezed"; on the tension side the fibers "are being stretched."

On a house, the roof becomes one of those supports. The trunk may bear on a ridge, an eave or a wall, limbs may be driven into the roof deck, and the root end may still hold in the yard, the condition the New Jersey investigators listed as a contributing factor: "Tree was downed, partially attached." The wood spanning those supports is bent, which is what the emergency page means by "loaded like a spring."

New York's Department of Health says "The quick release of that stored energy by cutting with a chainsaw can result in unpredictable results." NC State Extension flags limbs "under tension that may unexpectedly spring back," and OSHA's hurricane guidance tells tree workers that if a tree is broken and under pressure, "make sure you know which way the pressure is going."

In that New Jersey storm cleanup case, a hurricane-downed oak still attached above its stump was being cut up on the ground; as one piece was cut free, "the remainder of the tree pivoted" at an earlier cut left unfinished and came down at a sharp angle. The investigators recommended taking limbs off the upper canopy before the first trunk cut, because that "can reduce the weight and tension."

On a house the stakes rise, and the USDA Forest Service warns that tree removal "is even more serious when homes and other targets are involved."

On a house, what crane-assisted tree removal adds is that each piece is held before it is cut; the pick itself belongs to the order of a crane day. On a roof, that order puts the weight on the crane while the wood is still whole, so finishing the cut does not drop that piece's weight into a damaged structure.

The federal crane rule for general industry, 29 CFR 1910.180, is the standard OSHA's tree-care inspection memo tells inspectors to check truck-mounted cranes against. It requires care during hoisting so that "The load does not contact any obstructions," and it says "Cranes shall not be used for dragging loads sideways." Both point to pieces that hang free and rise clear, not a tree pulled across the shingles.

The work falls to the certified crane operator and the tree climbers: the climbers work the cuts and the operator runs the crane. For everyone else, the general-industry crane rule is plain: "The operator should avoid carrying loads over people," and "No person should be permitted to stand or pass under a load on the hook." A room under the tree is under the lifts, and for the household the first-hour page is plain: nobody goes on the roof.

As the pieces come off, the roof is uncovered a little at a time, and the damage shows fully once the weight is gone. Repairing the roof is a separate trade's work and part of the insurance conversation, which tree damage insurance claims in North Carolina takes in order. On that side, we work with your insurance company to make the process smoother.

A crane needs a setup spot within reach, and some lots do not have one. Then climbers take the tree apart on ropes, and the order of cuts matters just as much, because every rope anchor and lowered piece loads a tree still resting on the structure. Crane or climber weighs the two methods, and dead and rotten trunks covers wood that cannot be trusted.