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How to Take Down a Wall

Tom Silva and friends take down an outdated carport by hand in the Cambridge house

How does This Old House general contractor Tom Silva take down an outdated, nonfunctioning carport? On the count of three, naturally.

The carport is just one bit of sad architecture on the 1950 Modern-style house that is the current TOH television project, and it needs to go to make way for a real garage. So Tom has enlisted TOH host Kevin O'Connor, homeowner George Mabry, and Silva Brothers crew member Mike Sheridan to help him give the last wall one big tug.

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But before the four could get to this dramatic point, Tom's crew worked all morning at the site in Cambridge, Massachusetts, carefully dismantling the structure. They ripped off the roofing, cut the joists, and detached the fasteners tying it to the house, so as not to take down more than they bargained for.

The new garage is just one aspect of the house's remodel, which will require a lot of demolition. Literally tons of old walls, plaster, pipes, and sheathing, along with the home's leaky roof, have to go before Tom can add on a first-floor library and bump up the second story. But the plan also calls for leaving much of the existing home intact, including nearly all of the exterior walls and one perfectly good kitchen.

Most renovations actually work this way: Change some sections, save others. Very few are wholesale teardowns, so it's not possible to simply drive up with a wrecking ball and swing away. "It requires controlled emolition — handwork," says Tom. "You're trying to be gentle with the salvageable parts."

Enthusiastic amateurs get into trouble when they tear into walls without stopping to learn what they'll find inside them. "They can end up removing structural elements or hitting pipes and wires," says Tom. To be safe, walls and roofs should be systematically

disassembled in the reverse order of how they were put up.

So if your remodel requires taking down a wall or tearing off a roof — and you've got the nerve to try it yourself — turn the page to learn how the pros do it right. Of course, to play it safe you still might want to get the advice of an engineer. After all, additions cost a lot — but not nearly as much as a whole new house.

Prepping the Area

Before you begin: Always wear steel-toed boots, gloves, goggles, and a respirator (rated against lead-paint dust if your house was built before 1978). If you suspect you might have asbestos in pipe insulation or floor tiles, do not go near it. Contact an abatement specialist instead.

1. Isolate the work area using 6-mil plastic sheeting sealed with blue painter's tape.

2. Protect floors against falling debris with particleboard over builder's paper.

3. Order a Dumpster in advance. Make sure you clear an area close by for it.

4. Shut down water and gas lines and turn off the power to the room. Try to turn on the stove and faucets to check them. Use a voltage tester on outlets and switches.

5. Remove door trim and baseboards. If you're reusing trim, carefully pull it off the wall with a painter's pry bar. Start at the ends for the best leverage. Remove nails by pulling them from the back. Store in a dry location.

6. Remove doors and hardware. Store doors in a dry place if reusing.

7. Remove windows. Pry off the stops along the jamb. Take out the sash. Pry out the framing members.

Taking down the Walls

1. Determine if a wall is load-bearing.

All exterior walls are. Interior ones typically run perpendicular to joists (parallel to floorboards). Or look in the basement for support posts. When in doubt, consult a professional home builder or engineer.

2. Erect shoring around load-bearing walls. Build a pair of 2x4 stud walls four feet to either side of the existing wall. (This is not necessary if you plan to remove the roof or floor above, which should come first.) Build the shoring walls on the floor and tilt them up. Or you can build them in place, first nailing the top plates to the joists, then using a plumb bob to locate the bottom plates and nailing them down. Make each wall 1/4 inch too tall, forcing it into position with a sledgehammer to relieve the load on the existing wall.

3. Cut plaster-and-wire-lath walls with a circular saw. Fit it with a diamond or carbide blade. (The stone plaster used with wire lath ruins reciprocating-saw blades.) Set the depth to 3?4 inch and cut out rectangular sections. To reduce debris, try to keep the plaster attached or "keyed" to the lath. Watch out for sharp wire edges.

4. Cut through plaster-and-wood-lath walls with a reciprocating saw fitted with a 7-inch blade. Hold the saw at a very acute angle. When you feel the blade penetrate through the lath, do not go any deeper as you may hit pipes, vents, or wires.

5. Pull drywall down with a wrecking adze or pry bar. This will also work for plaster and lath if you're not comfortable using a saw.

6. Cut copper pipes with a pipe cutter if they will remain in the walls. Cap or

reroute them. If the pipes will be pulled out altogether or are PVC, cut them with

a hacksaw or a reciprocating saw fitted with a bimetal blade. Recycle the copper.

7. Do not leave electrical wires hanging, even if they're dead. This violates the National Electrical Code (NEC). Either remove them back to the closest junction box or circuit breaker, or reroute them to a different location and terminate them at a new junction box. It's best to consult a licensed electrician if you plan to keep the wires in use.

8. Knock studs out from the lower end with a sledgehammer. Or for a more delicate removal, cut through nails at the ends of studs with a reciprocating saw.

9. Pry off top and bottom plates. For the best leverage, start at the ends and work toward the middle.

Tearing off the Roof

1. Pull up shingles (or tar) and roofing paper with a shingle remover or adze.

2. Drop roofing onto tarps or, better yet, directly into the Dumpster. Use a tarp to make a slide from the roof.

3. Dig out nails in plywood sheathing with a cat's paw, then lift up the sheets. Pry up board sheathing. Consider reusing boards.

4. Remove rafters on either side of the ridge beam, chopping off the ridge

as you go. On flat roofs, cut away and remove joists.

Where to Find It


Will Ruhl, AIA,

Boston, MA;


Demolition contractor:

Bob Gagliard

Gagliard Contracting

Westwood, MA


National Electric Code (NEC):

The National Fire Protection Association (NFPA)

Quincy, MA