Repairing the metal that seals wall-to-roof joints, dormers, valleys and pipe penetrations on older Newton-area houses.
Fastest: call (833) 751-2102. Or send this and we call you back.
Flashing is the thin metal, usually aluminum, copper or galvanized steel, that sheds water at every place a roof meets a wall, a dormer, a valley or a pipe. When it lifts, splits or loses its sealant, water gets under the shingles. Newton Roofing connects Newton and Middlesex County callers with an independent roofer who repairs it.
Most roof leaks do not start in the middle of a shingle field. They start where two surfaces meet. A roof that runs into the side of a second-floor wall, a dormer cheek, the throat of a valley and a plumbing vent are each a joint, and each joint depends on a strip of bent metal to throw water outward and downward. When that strip is bent, pulled loose, corroded or buried under old sealant, the shingles beside it can look perfect while the ceiling below stains.
Greater Boston has plenty of joints to look after. Newton's median house was built in 1942 and close to half the homes predate 1940, according to the figures published for the city, and houses of that age were built with dormers, bays, porches tied into the main roof and additions added in later decades. Each addition created another wall-to-roof line. Repairs have often been layered over repairs, so a roofer opening up one corner can find three generations of patches.
On a call to (833) 751-2102 you will be asked where the water shows up, what floor it is on and whether the spot sits below a wall, a chimney or a dormer. That is enough for the line to put you through to an independent roofer who serves your town. The roofer, not Newton Roofing, inspects the metal, quotes the repair and does the work.
Because water follows gravity to the weakest line, and roof joints are weaker than open shingles. Flashing sits at the exact points where a roof changes direction or meets something taller, and it fails from movement, rust or old sealant long before the shingle field does. That is why a leak often traces to a few feet of metal.
A shingle field is lapped like fish scales: each course covers the nail line of the course below. A flat run of shingles is forgiving. A joint is not. At a wall, the shingles stop and something has to carry water over the gap, and that something is a strip of metal with a few nails and a bead of sealant holding it.
Roofs also move. Wood expands and shrinks with humidity, and in a New England winter the ice that forms in a joint can pry metal up a fraction at a time. A joint that has been resealed three times has usually failed three times.
Yes. Slate roofs are usually flashed with copper or other sheet metal, and repairs tend to mean matching the existing metal and lifting slates without breaking them. The roofer should be comfortable with slate, because a standard asphalt crew can crack slates just by walking across them.
In Waban and Newton Highlands the older houses include Queen Anne Victorians with slate roofs, and repairs there usually mean matching slate, flashing and valleys rather than swapping a whole roof. In Brookline, permits on historic slate roofs have included new copper flashing alongside replacement of broken slates with matching-color slates. In Cambridge, one case before the Cambridge Historical Commission discussed restoring a slate roof with salvaged slate and replacement copper valleys and flashing.
Those are examples of how a flashing repair on an older house can turn into a materials question. Our slate roof repair page covers the roofing side of that decision.
The roofer checks whether the step flashing runs the full length of the wall, whether a cover piece or siding laps over the top, whether any sealant is hiding gaps and whether the bottom end of the wall has a kickout that sends water into the gutter instead of behind the siding.
That last piece, a kickout, is easy to miss. Without one, water that runs down a sidewall can shoot behind the siding at the end of the roof edge, and the damage shows up months later as stained trim or a soft wall.
Ask the roofer to show you photos of the wall line before and after. Whatever the repair costs, you should see which joints were opened.
Do not climb onto a wet, icy or snow-covered roof to look at a joint or to apply sealant. Water that has reached a ceiling light fixture or a switch is an electrical problem first; keep clear of it and call an electrician if the fixture is wet.
The roofer starts with where you saw water inside and works uphill, because a stain on a ceiling can be several feet below the opening. Wall lines, dormers, valleys and pipes get the first look.
Exposed flashing is checked for splits, lifted edges, rust and nail heads that have backed out. The roofer also checks how the metal is fastened and what has been smeared over it, since heavy sealant often hides a failed joint instead of fixing it.
A proper repair usually means lifting the shingles or siding that cover the top edge, removing the failed piece and checking the sheathing beneath for rot or stains before new metal goes in.
New flashing is layered so every piece overlaps the one below it, with step pieces woven into shingle courses along a wall and counter-flashing or siding laid back over the top. Water has to keep running over metal, never behind it.
Fasteners and any exposed edges are sealed, shingles and siding are put back and the roofer should tell you which joints were repaired and which were left alone. Ask for that in writing with the quote.
Where a sloped roof meets the side of a wall, small L-shaped pieces step up with each shingle course and a cover piece, counter-flashing or siding, goes over the top edge. This is the joint at second-floor walls, porch roofs and additions, and it is the one that most often shows up behind a ceiling stain on an older house.
A valley is where two roof planes drain into one channel, so it carries more water than any other line on the roof. Open metal valleys, woven shingle valleys and closed-cut valleys each fail in a different way. On slate and copper work, valley metal is often replaced before the slate itself.
Dormers have a front apron and side pieces on each cheek. Bay windows and roof-top vent pipes each have their own flashing or rubber boot. These small details are cheap parts that cause outsized trouble, because their joints open and close with every freeze and thaw.
On a triple-decker or an addition with a flat section, the membrane turns up the wall and finishes under a metal cap or counter-flashing. The detail is different from a shingle roof, and the roofer who handles flat roofs should look at it. See the flat roof and EPDM page for the membrane side.
Flashing work is priced by how many joints are involved, how hard each one is to reach and what lies under it. No local price is published for it, so this page carries no dollar figures.
| Job | Typical range | What it includes |
|---|---|---|
| Resealing or re-securing one accessible joint | Quoted on site | Limited to joints in sound condition; the roofer should say why a reseal is enough |
| Replacing flashing at one wall, dormer or valley | Priced by length and access | Includes lifting and replacing the shingles or siding that cover the edge |
| Vent pipe boots and small penetrations | Usually the smallest line on a quote | Several are often done in one visit |
| Repairs that uncover rotted sheathing | Added once the damage is seen | Ask for the rule for replacing decking before work starts |
These are descriptions of what drives the price, not quotes. The roofer confirms the scope and a written price on site before any work starts.
Call any hour and explain what is going on. You get a clear price before any work starts.
Older houses in Waltham, especially the mostly wooden multi-unit buildings in South Waltham, sit on small lots with shared walls and small roof footprints. Roofs like that have more wall lines per square foot of shingle than a ranch house does, so flashing is where a roofer expects to spend time, and tight access can change how the work is staged.
In Arlington, one source puts about 47 percent of homes as built before 1940 and another about 46 percent. Older framing, chimneys and flashing that has been patched more than once go with houses of that age, so a roof inspection before quoting tells you more than a look from the street. Weston has larger houses on bigger lots, with many valleys, dormers and chimneys, which raises flashing work and the cost of a roof.
Newton's Building Department is described as stricter than the standard model code, and a full replacement needs a building permit. A flashing repair on its own is a smaller job, and published summaries say minor repairs do not need a permit, but the department decides for your address, so ask before you assume. Inside a local historic district, new metal may need commission review for its type and finish.
Counter-flashing, saddles and crown checks for brick chimneys that cross the roof on older Newton-area houses.
Leak tracing and repair for Newton roofs, from chimney and valley leaks to meltwater that backs up at the eaves.
Reflashing, resealing and replacing skylights whose curbs and seals have aged, plus new skylight openings on older roofs.
Repair of cracked and slipped slates, copper valleys and flashing on historic Newton, Brookline and Chestnut Hill houses.
Not sure if you're covered? Check your ZIP code.
Most slate roofs are repaired rather than replaced, because the slate itself often outlasts the nails, flashing and valleys around it.
Flat roofs on triple-deckers usually fail at seams, drains, parapet walls and penetrations rather than across the open field.
Check where the stain sits. A ceiling mark directly under a wall, dormer, valley or pipe points to flashing, while stains spread across the middle of a slope can mean worn shingles or failed underlayment. The roofer settles it by tracing uphill from the stain and checking the attic side of the sheathing.
Because the water is hitting the joint sideways instead of running over it. A step flashing that is too short, a missing cover piece or an open sealant line lets that sideways water in while straight-down rain runs past. Tell the roofer which direction the wind blew and which wall was wet.
Published summaries say a full roof replacement needs a Newton building permit and minor repairs do not, but the Building Department decides for a specific address and job. A flashing repair that involves rotted decking can become a larger job, so ask the roofer to confirm with the city before work starts.
Usually yes. Replacing shingles over old metal means any weakness stays hidden under new roofing. Many roofers renew step flashing, valleys and pipe boots as part of a tear-off, and your written quote should list each one. If it says only shingles, ask what is happening to the metal.
It is worth raising if your roof is slate, if a historic commission has views on materials or if you want metal that matches existing copper. Brookline and Cambridge records show copper flashing in historic work. Whether it fits your budget and your roof is a conversation with the roofer.
Those have their own flashing details and their own failure patterns. A chimney crosses the roof plane and needs counter-flashing set into the brick, while a skylight has a curb or frame that sheds water on four sides. Read the chimney flashing and skylight leak pages.