Flashing consists of metal - which is durable enough to be exposed to sunlight and mechanical wear and tear - plus peel-and-stick membrane like Vycor (Grace Construction Products; 800/354-5414, www.graceathome.com) or BT25XL (Protecto Wrap Company; 877/271-9661, www.protectowrap.com), which seals around punctures from nails and bolts.
Tearing into siding is all but inevitable if you build decks on existing houses. It's necessary to remove (and replace) several courses of siding to flash a ledger properly; only then do you have access to lift the building paper and apply peel-and-stick membrane and metal flashing the requisite 6 inches up the wall (see illustration, above). Also removing a little siding beyond the left and right ends of the proposed ledger allows you to apply peel-and-stick membrane there to protect against leaks. The flashing can then lap the top of a lower course of siding, or the foundation, so any water that does get into the joint will be directed outward.
I advocate removing siding carefully so it can be reused. This is both greener and cheaper, and it usually looks better to reuse old siding than to patch in new and try to match the existing finish. Siding can be gently (but pretty quickly) removed with a few tricks.
Face-Nailed Lap Siding
A number of face-nailed wood lap sidings - clapboard, Dutch lap, some hardboard panels, some engineered lap - can be easily removed and replaced, because the nails are accessible (Figure 1). The course overlaps are generally between 1/2 inch and 2 inches; face nails may or may not clear the siding beneath. When they do, removing and repairing siding is easy: You extract the face nails from any piece and pull it down and out. But more often than not, nails are driven through both the upper course and the top of the lower course, so you need to take extra care when dismantling to avoid splitting the siding.
I prefer to pull the nails when at all possible, to minimize the damage to the wood. Assuming the face nails penetrate the top of the siding course below, start removing nails in the course above the highest course you actually want to remove. Use a very stiff-bladed putty knife or a thin and wide flat pry bar.
Insert the tool under the siding directly beneath or just alongside each nail, tap the blade, and pry the butt edge up about 1/8 inch (Figure 2). Keep an eye on the nail head to make sure it rises with the board. If it doesn't, take the pry tool out, tap the nail lightly in, then try prying it up again. This trick sometimes frees up a stubborn nail. Once you've lifted the siding and nail 1/8 inch, pull the pry tool out and tap the siding back down to leave the nail head standing proud (Figure 3).
Now you can get purchase on the nail and pull it out. Work your way along the board, pulling all the nails; then drop your attention to the course beneath and follow the same process. Once you get all those nails out, you should be able to draw the siding down. With the first course removed, continue down until you clear the work area. Because lap-siding joints are offset from one another, you'll have to remove nails a little farther to the left or right to disengage the top lap of some courses.
Stubborn nails that can't be pulled out can be cut off. Use your prying tool to lift the clapboard up 1/8 inch to 3/16 inch. The nail head will sink into the wood as you do this, so be careful not to pry too hard. Slip the tip of a metal-cutting reciprocating saw blade into the space and brace your hands well before starting the saw (Figure 4). I find a medium speed works best to prevent the saw from bucking.
Even after you cut the nails on the first siding course, the shanks will still hold the top of the lap beneath. To disengage the siding from the shanks, slide your pry tool up farther and lift. Once one course is removed, the rest will go like clockwork.
You can also drive the nails through the siding with a punch or nail set (Figure 5). Small-headed siding nails usually won't tear out the back of the boards, so the siding can be reused. The holes can later be filled, or larger nails can be driven through the same holes. However, driving large-headed nails through the siding can damage it beyond reuse.
Because of the greater overlap and the blind-nailing pattern (Figure 6), shingle siding is more challenging to work with than lap siding. If having roughly two-thirds of the shingle body covered by the shingles above and being blind-nailed wasn't enough, the nails holding the course above also penetrate the upper part of your target shingles.
As with lap siding, extracting the fasteners on the first course is the hardest. Once a course is removed, the blind fasteners of subsequent courses are exposed and thus simpler to remove.
There are two ways to remove shingles. The difficult way is to remove the entire first course. The other method is much easier but involves cutting a course of shingles, which leaves a less than perfect overlap when reassembled. Either way, number the shingles to make it easier to reinstall them.
I use two tools simultaneously to pull nails and remove shingles: a thin flat bar and a slate ripper (Figure 7). Sometimes called a nail ripper, a slate ripper is designed to cut or pull nails from between roof slates. It's a long flat bar with an upturned handle, and at the business end it has small J hooks that grab around the shank of a nail or legs of a staple. With a few downward raps on the handle, the hook either cuts through the fastener or pulls it out.
Removing an Isolated Section of Clapboard
I doubt there's a deck builder out there who hasn't damaged a piece of siding that's outside the area that requires stripping. If the damage is small, you can often just cut out the bad part and leave the rest, minimizing the work.
I guide a Japanese-style pull saw with a square-cut wood block to cut through the board around the damage (above). The nails can be removed using any method. Remove additional nails within a foot either side of the cuts so you can pry up the course above enough to slip a small knife beneath to cut the head lap. If you damage the building paper making the cuts, patch with flashing tape before inserting a new piece of siding.
It's hard to maneuver the slate ripper beneath shingles, which is where the flat bar comes in. Use the flat bar to lift the shingles slightly off the ones beneath. I like to pry along the whole course I intend to remove and return with the nail ripper to get the nails.
It's still tough to pull the shingles out after the primary nails are removed, because the nails from the course above are still holding them in place. You can cut or pull the nails in the overlying course or grip, wiggle, and pull the shingle down. Most of the time, the shingle fibers will give up around the fastener legs and pull out. For stubborn shingles, I use wide-jawed clamping pliers meant for bending metal to grab hold of the butt (Figure 8). Sometimes a shingle will split when it's removed and will have to be replaced.
After you remove the first course, the fasteners holding subsequent courses will be exposed. You can proceed by using any of the previously discussed methods to free the rest of the shingles. I prefer to pull the nails; since the nail locations are hidden by the overlying courses, you can use a cat's paw-style nail puller and not worry about scarring the shingle surface.
The easier way to remove the upper-course shingles is to cut them. Use a sharp utility knife and cut along the butt line of the overlying course. Angle the blade between 30 degrees and 45 degrees upward. Lower courses of shingles will come out after you remove the fasteners holding them. The downside to this method is the minimal overlap joint when you reinsert the cut shingles.
Reinstalling shingles is straightforward until you get to the last course. If full shingles were removed, you'll need to fasten them with face nails. The nails can be somewhat concealed by leaving the butts of the last course of shingles about 1/4 inch lower. Drive two stainless steel siding nails into each shingle, angled up at 20 degrees to 30 degrees, directly beneath the butt of the overlying course. Set the nails flush with a nail set and tap the butt of each shingle upward until it's properly aligned (Figure 9). Tapping the shingle upward will also push the nail heads upward beneath the shingles above, concealing them.
Before reinstalling shingles that were cut from the wall, make repairs to the building paper. Odds are it's been cut somewhere. Then just replace each shingle in position and drive stainless steel face nails about 1 inch below the butt overlap. The nails will remain exposed.
Repairs to damaged shingles are much easier than repairs to lap siding. You can just extract an individual shingle or a couple of shingles using either technique above. When the damage is to one or two shingles, I usually knife-cut off the exposed portion of the damaged shingle and insert the butt of a fresh shingle.
Blind-Nailed Lap Siding
Fiber-cement and several engineered lap sidings are similar to wood lap except they're usually blind-nailed along the top edge (Figure 10). Also, they're brittle: You have to be careful when prying to avoid breaking out the material around the fasteners, and you can't use the slate ripper on nails in fiber cement because the siding tends to fracture during the process.
Instead, I use a nail cutter from Malco Products (800/328-3530, www.malcoproducts.com) that works like a pair of thin bolt cutters (Figure 11). With a flat bar, pry up the butt of the course you want to extract, slip the nail cutter beneath, position the jaws around the nail, and snip. Removing the upper piece of siding provides access to the nails in the next course, which can usually be pried out fairly readily.
Lacking a pair of nail shears, you can cut the fasteners with a long metal-cutting blade in a reciprocating saw. Insert a couple of thin wood wedges or shingles under the lap to separate the fiber-cement siding so you can slide in the blade. Brace yourself and cut at slow to medium speed.
When replacing panels, you can usually hand-nail engineered lap siding, but fiber cement requires a nail gun, for a couple of reasons. First, it's hard to hand-drive nails through the tough material - and second, multiple hammer strikes will usually break out the backside. If you don't have a siding or roofing nailer, I suggest predrilling holes for nails or screwing the siding down with pan-head screws.
The last piece of siding you reinstall will require face nailing. You can gun-nail, hand-nail through predrilled holes, or screw down the siding. With any of the fastening methods, be sure not to break the surface of the siding - just bring fasteners flush with the surface, or you'll weaken the material (Figure 12). Also, use stainless steel or hot-dipped galvanized nails where you face-nail the siding, to minimize the chance of rust.
Vinyl Lap Siding
The simplest siding to remove, replace, and repair is probably vinyl lap siding (Figure 13) because you can unzip the overlaps - without pulling out nails. Use an unlocking tool like Malco's SideSwiper, sometimes called a €œzip-lock€ tool (Figure 14). Hook the little €œJ€ end under the butt of the overlapping panel at the level where you want to begin removing siding. Once you push the end of the tool up, the hook will grab the lower edge of the lap. Slide the tool along the siding, pulling slightly toward you to disengage the lap.
In a pinch, you can use a small flat bar to unlock vinyl-siding laps. The trick is to grab the locking edge of the siding and pull down and away. A flat bar will pop off the edge from time to time as you slide it along, whereas a zip-lock tool won't.
Once disengaged, the bottom of the upper panel can easily be lifted upward to expose the nails holding the siding beneath (Figure 15). The heads of the fasteners are usually left 1/16 inch to 1/8 inch proud of the vinyl hem, which makes them easy to grab with a hammer claw or pry bar. Even though vinyl-siding panels are commonly 12 feet long, it's easier to remove entire panels than it is to cut them in place and remove portions. Later, you can quickly fill in pieces where needed.
After you install the ledger and decking, you'll need to apply vinyl J-channel around them to receive the edges of the vinyl siding. The J-channel permits the vinyl to expand and contract with temperature changes without showing visible gaps.
Vinyl trim and panels cut easily with metal snips, a utility knife, or a circular saw or miter saw outfitted with a plywood blade - installed backward for clean cuts. If you'll be cutting a lot of vinyl with a power saw, spray the tools and yourself with anti-static aerosol, such as Static Guard, to reduce the clinginess of the vinyl dust.
Vinyl responds to temperature change by expanding and contracting significantly. When cutting vinyl to length, you need to consider the ambient temperature. On days above 85°F, cut the panels so there's only a 1/8-inch gap to the bottom of J-channels. When temperatures are between 40°F and 75°F, leave 1/4-inch gaps. Below 20°F, go for 3/8-inch gaps. Adjust for the extra 1/16 inch at the interim temperatures.
Reinstalling vinyl is easy. Just hook the bottom edge into the top locking edge of the panel beneath. Lift up, and you'll feel the joint engage. As you nail, keep lifting so the lap is snug but not deforming the butt edge. Drive nails in the center of the nail slots, leaving the heads proud 1/16 inch so the panels can expand and contract.
After nailing in the last panel, you'll need the zip tool again, to join this panel to the one above it. Hook the tool to the bottom of the upper panel and pull downward so the butt edge can engage the lock edge. Press the butt edge into the wall as you slide the zip tool along the wall (Figure 16). The vinyl panels should lock together. Look beneath the lap to make sure you didn't miss any spots.
The shingle panel-style of vinyl and polypropylene sidings have manufacturer-specific interlocking systems that may or may not be able to be disengaged in the field of a wall. Check with the siding manufacturer for instructions.
Mike Guertin is a remodeler in East Greenwich, R.I., and a presenter at Hanley Wood's DeckExpo and JLC Live shows.