Expert tips for making jobsite flashings from aluminum coil stock.
By Mike Sloggatt. We brake metal all over our remodeling projects and use it for everything from flashing to fascia material. Over my 20-year remodeling career, I've learned a few things about getting it right. A simple gauge, proper nailing, and using the correct bends speeds up installation, prevents callbacks, and makes it look better when you go to the client for the last check.
LayoutWork Table. I set up the brake with a site-built layout table for easier handling, marking, and processing of the metal. I use 2x4s and 3/4-inch plywood on sawhorses set flush with the mouth of the brake. It's a great place to store pre-cut lengths of stock without disfiguring it, and it's mobile, which is important for working your way around a house. And for coils that I want to keep rolled up, I pinch them with a spring clamp.
Measuring. Since there are lots of different markings needed for layout -- to show bends and cuts -- I use consistent layout language to help prevent cutting my bends and bending my cuts. I use an "X" to show my cuts and a straight dash for the bends, and I always mark from left to right.When the bends get more confusing, which means there are lots of marks on the metal, I add a few steps. If a bend needs to be made from the opposite side I'm laying out, I place an "O" next to the mark as a reminder where to bend it. By flipping the piece over, I can transfer only the marks that relate to that side of the piece. If there are lots of repetitive opposite-side cuts, I make a separate O-side pattern piece out of scrap.
Hook-Gauge. A great layout trick is to make a hook-gauge. Take a 2-inch-wide (or so) piece of scrap about 26 inches long and fold over the end, forming a hook. Hook it over the piece you're laying out. Pull out your tape and record your measurements. As you mark the piece, mark the gauge too. Bring the gauge down to the other end of the piece, then transfer the marks accurately without your tape. Also, instead of adding up all your measurements to get the total width of your piece for cutting -- 1-1/8 up, plus 5-5/8 over, plus 5-1/2 up equals 12-1/4 inches -- measure the length of each bend individually, then cut the piece. Also, once you make a mark, say 1-1/8 inch, move your tape to a whole number (like 1) for your next measurement. Adding up all those 1/8 and 1/16 measurements is too confusing.
The Basic BendsThe L. This simple bend is good for concealing things. We use it a lot for hiding the end cut of vinyl soffit material and for the bottom trim band on bay windows. Sometimes, we take the L right up a piece of fascia. We also use it to cover the underside of exposed foam insulation at the starter course of new siding jobs. It provides a clean, crisp look.We use the L to form off-angles for various applications, like capping a shed roof, the base flashing on a dormer, or the center of a valley flashing. In the first two examples, I lay the metal flat on the shingles, then glue on a dummy course of shingles to hide the metal. If the metal is exposed, I crease the flange of the L that will sit on the roof to stiffen it.
The J. You can make custom J-channel and hooks on rake fascia with the J. When fabricating pieces with multiple bends, bend the J first; if you don't, this can sometimes prevent you from making the other subsequent bends. Also, since bends of 3/4 inch or less can be tedious on some brakes, I usually make the short leg of a J 3/4 inch and cover any offset that it creates by lengthening the long leg of the J.Add a 1/2-inch cap-bend at the top of your soffit J -- bent away from the soffit. This significantly increases the stiffness of the piece and dramatically reduces the number of nails required to fasten it.
The U. This is the most common bend for capping window and door trim that sits proud of a house's sheathing. Requiring only two bends on the same side of the coil, it's simple to install. For posts, we use two different sized Us. The larger U covers three sides of square posts. The smaller U is placed on the front side as a cap. The secret to getting this to work and not to "oil-can" is to build in 1/16 inch of play per bend to account for wane in the post material. The other trick is to use as few nails as possible, and don't over-drive them.
The Hem. One drawback to the bends listed above is their sharp edges. In areas that might contact people, or for a cleaner look, a hem is great. Make a 1/2-inch bend as far as the brake will go, then flip the piece and crush the rest of the bend flat in the brake's jaws.Since round and curved windows are common on our jobs, I fabricate a skirt or head flashing with metal. I hem my leading edge as flat as possible for a smooth curve, then butt it to the sheathing. To finish off the wall side of the flashing, I fold an ice and water membrane over the top of the metal.
Mike Sloggatt is a remodeling contractor in Levittown, N.Y., and is part of Hanley-Wood's JLCLive! demonstration team.