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Does flashing go over or under shingles?
Flashing should overlap the roof-covering material, but on asphalt shingle roofs, for aesthetic reasons, the part of the headwall flashing that extends down over asphalt shingles is often covered with a course of shingle tabs.
Can you add flashing to an existing roof?
Flashing is generally installed at any joints or edges in the roof where water could otherwise work its way in. In order to properly install new flashing, you’ll have to remove the shingles surrounding your old flashing, and then re-lay them after installation.
Where should flashing be used on a roof?
Flashing is critical to certain areas of your roof — namely, the places where the roof surface meets a wall (sidewalls and front walls), the low points where two roof slopes meet (called valleys), roof protrusions (bathroom/kitchen vents, skylights) and the roof’s edges (rakes and eaves).
Should you caulk flashing?
It is generally not a good idea to use caulking on wood siding. Flashing acts as a waterproofing layer for this type of siding, and caulking will prevent the flashing from doing its job. As far as trim boards are concerned, you should not caulk around these areas if they sit on top of the surface of your siding.
Can you install step flashing without removing siding?
Retrofitting Step Flashing Without Removing the Siding Our solution was to cut a 6-1/4″ of the siding away, creating a space to allow the installation of step flashing. We would then cover this space with a removable trim board. We made sure to keep out fasteners high on the trim board and away from the step flashing.
How do I install continuous flashing?
To install continuous flashing, embed it into roof cement and nail it to the last course of shingles nailed to the deck. Do not nail the flashing to the wall. Instead install the flashing before the siding, bricks, or stucco. If the siding is already instead you will need to pry it up to slip the flashing under it.
Is step flashing better?
Step flashing offers far better protection from leaks, because even if a single piece of step flashing fails, the water just hits the next lower piece. That flashing directs the water onto the shingle and the water drains down the roof.
How do you seal roof flashing?
As long as the flashing has been installed properly, you can repair a leaking seam using simple roofing cement in most instances. Simply push the seam back down and secure it in place with screws if necessary, and then apply roofing cement around all the edges of the flashing for a watertight seal.
Is roof flashing necessary?
Roof flashing, usually made from metals like aluminum, copper, or steel, is flat and thin, and prevents water from getting under shingles. All of these areas leave shingles and underlayment vulnerable to water, so the flashing is necessary to prevent leaks.
What material is used for flashing?
What materials are used for flashing? Flashing can be made from many different materials, including metal (copper, aluminum, stainless steel, lead, etc.), plastic, or composite materials. The most durable (and, therefore, most expensive) flashing material is metal sheet flashing.
How do you seal the flash on a metal roof?
Renew flashing seals by chipping out the old mortar and caulking along the edges of the flashing. Use special masonry caulk to seal the joints between the flashing and the chimney. Seal the seam between the cap and step flashing with urethane roofing cement or silicone caulking compound, as shown at right.
Is a drip edge necessary on a metal roof?
A drip edge is not needed for metal roofing. If the metal roof is hanging over an inch, the water will be directed away from the fascia anyway if at a slant. However, it is highly recommended to install a drip edge to save from water damage later on.
Do you caulk Z flashing?
If the siding was installed with Z-flashing, do not caulk in the grooves. As for the type of caulk, if the siding is painted, use a good acrylic painter’s caulk. If the siding is stained, use a clear silicone caulk made for exterior use.
Why do you need Z flashing?
Z-flashing is required over horizontal wood trim pieces, typically seen above doors or windows as well as decorative trim bands. It channels water downward to the kick-out flashing, which is intended to manage water coming off step flashing.
How much should Z flashing overlap?
Cut Z-flashing with tin snips at the edges of the structure and overlap the flashing 6 inches if you have to install more than one piece.
Should flashing go under siding?
In certain instances flashing may need to be installed on the exterior of siding. However, in most instances, step flashing should be installed “behind” siding. It is always recommended to install step flashing behind stucco, Dryvit, wood panel, lap siding, vinyl siding, cedar shingle siding, etc.
