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You are finally ready to gather your forces for the demolition and construction ahead. This phase of the work can be both exhilarating and frustrating. Exhilarating because you can see your design slowly taking shape right before your eyes. Potentially frustrating because construction might not move as fast as you would like. If you are working with a professional designer and a general contractor, this phase should be relatively relaxing (unless you are forced to live in the building while the renovation is going on). We don’t advise you, however, to fly off to a South Seas island for the next few months. This is a renovation, rather than new construction, and there may be exigencies that couldn't be fore seen in advance. Your input may be required to resolve a problem (especially if the resolution generates a costly extra). Even if there are no major complications, it's a good idea for you to visit the site a few times a week, not only to see how the job is progressing but to check that every detail has been included. The designer may fail to notice that an electric outlet has not been installed in precisely the spot indicated on the drawings. Since you know exactly where you want to locate your computer, you are more likely to spot the omission than is the designer. If you are your own general contractor (or if you have prepared the construction drawings yourself and hired a general contractor), you will have to visit the site daily to resolve problems and answer questions. You will have to check the progress of the work, make sure that it's being constructed as drawn, that the workmanship is of good quality, and that the contractor is using specified materials. If you are scheduling the work, you will have a substantial amount of homework as well. Materials will have to be ordered, received, and paid for. Subcontractors will have to be called in when needed. The rest of this introduction is for those who will be constructing or supervising part of the work. Be advised that the directions outlined in the sections that follow can't be relied upon as your sole means of instruction in any single trade or for any particular procedure. There are a number of excellent comprehensive guides available covering carpentry, plumbing, and electric wiring (as well as the other trades) that must be used to supplement this guide. Be sure to read extensively before you attempt a job. Book learning, however, does not make up for experience. Think twice before attempting something that you have never actually done before. In addition, read and memorize the list of suggestions and precautions below before plunging in. In General 1. The evening before a day’s work, pore over the construction plans of the job ahead of you. Familiarize yourself with the details and be sure that you understand what is required in each step of the procedure. If you have any questions, call someone with experience, build a model of the questionable area, or consult your reference books for a solution. Don’t expect the problem to resolve itself the next day. It won’t. At best you will be wasting valuable daylight hours pondering; at worst you may have to rip out half a day’s work to remedy a mistake. Whenever possible, work with someone to prevent straining yourself. If you have a partner, you can discuss a procedure in advance. Two opinions on the subject may help you avoid doing something foolish. 2. Make sure you have all the materials and tools you will need for the day’s work. It is frustrating to have to stop work to search for a missing item. At such a time the temptation is great to substitute an inferior or ill-suited item for the one you are missing—a bad construction practice. 3. Be sure you have read and provided for all the safety admonitions in this guide, other books, and the instruction booklets of all power tools and for all materials. Remind yourself that people lose fingers by removing safety guards, and their lives by ignoring grounding rules. 4. Never drink alcoholic beverages or take drugs before or during work. With normal judgment impaired, you may feel like a superman or super woman—may think that you can work longer, harder, and faster than you ever worked before. This is the best way we know to hurt yourself. Besides, you will probably judge the work to be sloppy the next morning. 5. Don’t work where or when it's too dark to see, or when it's very cold or hot. Don’t work outdoors if it's raining or if surfaces are slippery. 6. Don’t work when you are exhausted or dizzy from the heat. 7. Keep work areas clean. It is very easy to slip on accumulated debris and sawdust. Often the wind sweeps unattached materials and debris onto the heads of workers and passersby. 8. Don’t use power equipment in wet or damp areas. Keep tools stored in dry, safe places when not in use. Make sure that all outside electrical outlets are covered by ground-fault interrupters. 9. Make sure you are dressed properly for this kind of work. You will need heavy shoes with thick soles and firm toes, a hard hat, work gloves, and a respirator (or masks rated for the type of work being performed). Use safety glasses when using power saws and other power tools. Do not wear loose clothing, necklaces, or long hair that might get caught in the machinery. Keep a first-aid kit on hand. 10. Be careful when handling, storing, or using flammable materials or chemicals. Avoid using materials with poisonous or noxious fumes. Follow all printed instructions. Use and store these materials in well-ventilated areas. Keep all tools and chemicals away from children. 11. Wear a suitable protective mask when installing fiberglass insulation or applying and sanding spackling compound or whenever a manufacturer suggests it. 12. Make sure that you, your house, any workers you may hire, or any subcontractors are covered by liability and accident insurance. Some co-op buildings require extensive liability and workmen’s compensation insurance. For Demolition Few items on the construction agenda are more dangerous than demolition. Don’t just jump in there and wreck the wall. It may be load-bearing, or alive with electric and gas lines, or full of asbestos. Since it may be more dangerous to demolish a structure than it's to build one, we urge you to consult an engineer or architect before cutting into or dismantling the structure of your house. Many old houses have complex structural arrangements that may confuse an expert, or may have been built using harmful materials such as asbestos (in pipe coverings, exterior shingles, floor and ceiling tiles, etc.). Even if you are relatively certain that you understand the structure and know what you are doing, get a second opinion. Before you demolish anything, prepare your self as follows: 13. Have all your demolition equipment ready. A list of materials and equipment can be found below. 14. Clear away all items in the room, or else seal them with drop cloths and tape. Even minor demolition generates an enormous amount of airborne dust. It may take four minutes to demolish a partition, but another two months to vacuum and dust the dishes, furniture, and books in the surrounding rooms. After removing everything you can from the room, close the doors and tape around the door seams. Tape around closet doors as well, or tape drop cloths over the doors. (The insidious dust seems to find its way through tiny cracks and around corners.) Open all of the windows and in stall an exhaust fan. 15. Protect the floors, if they are to be salvaged, by laying down old sheets of plywood (or Masonite) or, at the very least, taping heavy-duty kraft paper to the floors. 16. If possible, move out. Move to a hotel or a friend’s house or, if these aren't options, set up temporary cooking and sleeping areas (away from the demolition dust) so that you can do without the rooms being worked on for a few days. If you are demolishing part of your kitchen, it's unlikely that you will be cooking dinner there for a while. 17. Shut off the electricity in that part of the building. (You will have to use long, heavy-duty extension cords for any lighting or electrical equipment.) Shut off every circuit (even if it does not service the immediate area) that you can, and , if possible, shut down the whole house and get your electrical power from a neighbor. (To identify which circuits control what outlets, plug in a number of lamps to the outlets and turn off the circuit breakers at the panel box, one by one, until the lights go out.) If you are having work done on your apartment, make sure that, at the very least, your circuits are shut off. It may be impossible to shut down the electricity in the apartments above or next to you. Since there may be live lines in the partitions, the work will have to proceed with extreme caution. 18. If you have any suspicion that the gas line is in the partition you are dismantling, have a plumber or the gas company shut off service temporarily. If your house is relatively new, it will be easy to determine if there are gas lines passing through. Trace the line from the stove and clothes dryer to the gas meter and then to the place where the gas line enters the house. If you are demolishing any thing near that route, shut off the gas. In an older house or apartment building you may have more difficulty. Often there are live and dead gas lines that were originally designed to service gas-lit wall sconces and gas fireplaces. Also, an old apartment building may have seen a number of radical renovations. What is now the bedroom may have once been the kitchen. The gas line in the wall may still be active. Proceed with caution and if you hit a gas line call the emergency number for the gas company at once. 19. Shut off any water lines that might be running through the wall or ceiling about to be demolished. 20. Have the place inspected for asbestos. There could be asbestos in floors, pipes, valves, ducts, insulation, radiators, floor underlayments, etc. If the inspector finds evidence of asbestos, you shouldn't do the demolition yourself, but should hire a licensed asbestos-removal company. Should you attempt the demolition yourself, or hire inexperienced labor, you could be endangering yourself, the workers, and your family. 21. Rig up temporary lighting. Since you are shutting off electricity in the area, you will need construction lights on long extension cords. 22. Make sure you know how you are going to get rid of the debris. This might be the most costly and troublesome part of the demolition. If you are going to truck it away yourself, find out where you can legally dump the debris. If you have no way of hauling it off yourself, find a carter who will dispose of the debris legally. 23. Don’t pile debris in the middle of rooms. House and apartment floors are designed to support light residential loads only. They are likely to collapse under the weight of the accumulated debris. Some Demolition Guidelines 24. Try not to demolish more than you absolutely have to. If possible, plan to repair a surface rather than demolish and reconstruct it. 25. Remove everything that's salvageable before the demolition. Unpin door hinges and set the doors and the hardware aside. Doors (especially old, paneled doors or French doors) are very expensive and can be either reused or sold. If the doors have too many layers of chipped paint, they can be stripped and either repainted or stained and varnished. This is easily done by sending them out to a company for chemical stripping. 26. If the wood trim is intricate, you should try to save it for reuse. Gently pry it off using a small bar at the nail points. Wainscoting too should be salvaged if you can retrieve it in one piece and if it's not too dried out. Mantels, of course, should be protected if they are to remain in place or carefully removed and saved for relocation. 27. Demolition* should begin at the top and proceed downward, from the ceiling to the top of the walls, down the walls to the floor. Remove all of the plaster (or gypsum board) first (so that pipes, wires, etc., are exposed), the lath next, and the ceiling joists and wall studs last. 28. Be prepared to remove nails immediately from the lumber you will be removing. We suggest this for practical as well as safety reasons. First, you may want to reuse the lumber. Second, nails left in lumber cause nasty puncture wounds to the unsuspecting. Even if you are going to dispose of the wood, hammer the nails down, out of harm’s way. DEMOLITION EQUIPMENT:
*After temporary shoring is in place, if required. PREPARING THE SITE FOR AN EXTENSIONTHE LAYOUT The first and most important step in the construction process is the laying out of the extension on the property. We can't overemphasize this, since any error made at this point will interfere with every succeeding job. Inaccuracies in the measurement of the building walls or the angles at corners will manifest themselves in the remainder of the construction work. In addition, mis takes relating to the location of the extension on the property, such as being too close to a property line or violating code restrictions, will eventually cost you time and money to rectify. There are various methods of laying out. We have chosen the layout square method. It pro vides the degree of accuracy necessary for a small extension and it's very simple. Materials The materials and tools required for laying out aren't particularly difficult to come by or to operate. Many of them you can easily construct. You will need the following materials:
(Some of these materials will be employed in the construction of tools such as the layout square.) Tools Two types of tools are needed: tools necessary for laying out and those used for excavation. The following is a list of layout tools:
For excavation you will need:
Excavation is an exhausting, time-consuming, and tedious project. In addition, excavation close to an existing building requires a great amount of skill and care. This job is best left to a licensed and experienced backhoe and bulldozer operator. * (See section on excavation.) *A backhoe is used for small excavations. It has two attachments: a clawlike one for digging and a scooplike one for removing earth. Bulldozers have a plowlike element for pushing earth. They are used for leveling and large excavation jobs. *This procedure works for a flat or gently sloping site. For more difficult sites, we advise you to consult a professional surveyor. Both licensed surveyors and civil engineers measure land parcels, set boundaries, and draw up site maps. Locating the Extension Corners and Clearing the Site We remind you that although laying out the ex tension isn't a difficult process, it does require accuracy. If you aren't capable of precise work, we suggest that you subcontract this part to a licensed surveyor or civil engineer. For those of you with tight sites, we also recommend that you hire a surveyor or civil engineer, both to stake out your property and to site the new extension. There is a simple reason for this advice. We have seen many distressed homeowners requesting zoning variances from town zoning boards, the source of their problem stemming from discrepancies in siting between code requirements and actual dimensions. Those of you with large properties should look at the existing survey. Check to see if the distances between the proposed extension and the property boundaries are greater than the requirements specified by code. Bear in mind, however, that there may be zoning regulations governing the maximum building area or site coverage. Before you start clearing the site, post a grading or building permit or any other license needed to start work on your property. Clean the site of any roots, stumps, and tree limbs and remove any debris such as rocks or blocks of wood. Be sure to remove any underground wood that may eventually cause termite problems. If the topsoil is of good quality, remove it with a bulldozer for later use in landscaping. Be extremely careful about clearing this area. Look in the cellar to see where plumbing and electrical services penetrate the foundation. This will give you a clue as to the possible paths to a power pole, well, septic system, sewer, water main, telephone wires, etc. It is also advisable to check with the local building authorities for any old plumbing, gas, or sewer lines that were once part of a now demolished structure and might still be underground. These pipes should be properly capped with the required devices. There may be underground plumbing, gas, or sewer lines going through your property which service a nearby structure. The local authorities can also provide you with locations of municipal storm sewers. The power company can assist you in locating any underground electric wire or conduit from either a present or a previous electrical installation. In addition, the company can make sure that any installation is dead. CONSTRUCTING A LAYOUT SQUARE A layout square is essentially a large 90’ wooden triangle. To build it, you need three perfectly straight wood boards approximately 1” x 4” or 1” x 6” and 10’ to 1 2’ in length. Take two boards and carefully square off the ends. Make a lap joint at one end. This is done by making identical notches at the end of each board to half the depth of the wood. The pieces are then fitted together and nailed, screwed, or glued to each other. Then proceed as follows:
To use the layout square, place one of its legs directly under the stretched mason’s line. The notched end fits around the stake. Check for perfect alignment by means of a plumb bob. The adjacent leg will indicate where the next line should be located to obtain a right-angled corner. Let’s assume an extension that measures 14’ in width by 18’ in length. When the site is gently sloping, you need not worry about creating a level platform where the extension is to be built. Using the house as a guide, measure the length that the extension projects into the yard. With the use of a layout square take measurements 14’ away from the house and at right angles to it (assuming the extension is at right angles to the house). These measurements are taken at two points along the house and a stake is driven at each. Make sure that the stakes are care fully pointed—that is, all cuts are at even lengths; otherwise, the stakes will twist. Stretch a mason’s line between these stakes. The next step is to establish the intersection between the house and the extension. Measure along the house the appropriate distance from one of its corners to the beginning of the extension. Let’s assume 10’. Intersection A has now been located. Drive a nail into the building’s wall at this point. Starting at point A and with the aid of the layout square, find corner 1 by placing one leg of the square parallel to the side of the house. The adjacent leg will indicate the perpendicular. Where this line intersects the 14’ line, drive in stake 1. Stretch a mason’s line between points A and 1. Starting at point 1, mea sure along the line of the extension 18’ to locate corner 2. Place one leg of the layout square directly underneath line 1—2; the adjacent leg will locate point B. Drive a nail at point B. Measure the distances between points A—B and 1—2 and between A—1 and B—2 to make sure that they are 15’ and 14’, respectively. To double- check the accuracy of the corners, measure the lengths of diagonals A—2 and B—1. The diagonals of a perfect rectangle are always equal; should there be any discrepancy, readjust the lines accordingly by repeating the above procedure. Check to make sure that all yard measurements conform to code requirements. You should also check the lengths of the front and side walls of the extension. Keep in mind that all other construction is based on these first steps! Erecting the Batter Boards We now have stakes located at the extension corners and intersections with the main house. In our excavations for footings and foundations these stakes will inevitably be in the way and most likely will be lost. Remember that footings protrude a minimum of 4” outward from the walls of the extension (albeit underground) and that in addition to allowing for the footing projection, we need to allow room in which to construct the footing forms. The excavation should be at least 2’ greater than the perimeter of the house. So that we can remove the corner stakes prior to construction and still provide for easy location of the corner points, we erect batter boards. These boards frame the corners of the extension but stand 4’ to 8’ back from them, depending on the depth of the excavation. Erecting batter boards is a very simple procedure. The verbal explanation, however, tends to be somewhat confusing. We suggest that you refer closely to Illustration 8. Let’s assume that we are locating the batter boards 6’ outside the building lines. The first batter-board stake is located directly in line with the building-line diagonal. The distance away from the extension corner stake should be 10’. The second and third stakes are driven at right angles to the first, making sure that they are parallel to the building line. They should be located past the building corner, as shown in Illustration 8. We are now almost ready to nail the ledger boards to the stakes. Before doing this, the elevation of the top of the foundation wall must be determined. Determining the Floor Level There are several ways to determine the elevation of the existing floor. The most foolproof method, however, is to open a hole in the exterior wall and expose the house’s rough floor framing. A further advantage of this method is that in the event that you don’t have a completely level floor, you may adjust the extension’s floor wherever the openings between the spaces occur. If you are planning to have only a door between the extension and the house, open the wall in the location of the future door. With the opening in place, calculate the thickness of the new floor by adding up the various layers: framing, subflooring, flooring, and sill. Measure the distance representing the total depth of the new floor down from the existing floor level to determine the height of the new foundation. The next step is to transfer this height to the batter boards. This can be done with the aid of a transit. An easier method is to use a water level. A water level is a tube filled with colored water; it can be purchased at building supply houses. When you extend the tube and the water is level, it gives you a straight line. (The water level was used for the installation of acoustical ceiling tiles before the use of lasers became popular.) Hold up the tube against the building at the appropriate height. Stretch the tube out. When the water is level, transfer the height to the batter boards. If the extension is very small (about 10’ wide or less), you can site the elevation by using a straight piece of lumber and a 4’ carpenter’s level. Locating the Building Lines on the Batter Boards Locating the building lines on the batter boards is done by stretching a mason’s line between batter boards at right angles to each other. The mason’s lines are kept in place by attaching them to bricks. The lines are adjusted with a plumb bob until they intersect directly over the tack on the corner stake. Mark the location of the mason’s line along the batter board and cut a notch on it. Place the line on the notch, wrap it around the ledger board a few times, and tie it to a nail. Check the line for levelness by using a line level. The corner building stakes can now be removed. The nails indicating where the extension meets the house are located high enough on the existing foundation to remain undisturbed during the excavation. Once the building lines have been located, you can mark off the distance along the batter boards to the excavation lines. You should excavate at least 3’ out from the actual building lines to allow yourself room to work on the foundations. (See discussion on excavation. We can't overemphasize the danger of excavating too close to the foundations of the existing house and the danger of inundation and collapse.) Cut notches at the point where the excavation line will occur and transfer the mason’s line from the building line to the excavation-line notch. Using a plumb bob, drive a stake directly under the intersection of the stretched excavation lines. This locates the extension corners. Remove all lines from the batter boards. You are ready to begin excavation. EXCAVATION You can now instruct the backhoe operator to start excavating. Make sure that this person is experienced with excavation close to an existing structure. As we already explained in the section on foundations, it's very important that the existing building foundations and footings not be disturbed in any way. Undermining the building’s foundations by inundating the footings or pushing into foundation walls can prove disastrous. One safety measure which might help is to do the excavation close to the existing foundation (within 3’ to 4’) by hand rather than with a backhoe. We recommend (as we already stated in the foundation design section) that you have a crawl space for the extension rather than a full basement wall. The reason for this advice is that it will keep the excavation depth shallower than the depth of the existing foundation wall (assuming you have a full basement under your existing house). As we discussed in the foundations section, the new foundations will need to step down to the existing ones. The crucial point to remember is that you want to keep the excavation line above the line of the existing footings. In cold areas, you must take into account the depth of the frost line. The ground expands when it freezes, causing foundations that aren't secured by footings placed below the frost line to move, thus damaging the house. Local codes of building authorities can tell you the depth of the frost line in your area. More on safety: When trimming trenches by hand or doing any work involving digging, a few things should be kept in mind. Sandy soil requires a larger excavation, as it does not hold together. Soil with a high clay content will be more likely to hold up in a straight line. Earth is often unpredictable. Sometimes a bank that looks safe will cave in on you. A few warning signs to look for are cracks along the surface of the earth on top of the trenches or earth trickling down a bank. A good bet is to brace the excavation with boards placed vertically along the banks of the trench. In addition, store any excavated material way back. It shouldn't be piled close to the trenches. If you decide not to use bracing, at least slope the banks as much as possible, particularly in loose soil. Finally, it’s not a good idea to let the excavation stand idle for days. Storms, rain, and wind make the excavation unstable and can set off a slide. Next: Constructing Foundations for an
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