Old tar & aluminum-coated roofs
Silver coat roof replacement in Philadelphia
Thousands of Philly rowhomes still have a tar roof painted silver, often sitting on top of one or two older roofs. When the paint won't hold and the patches keep failing, it's time to take it down to the boards. Call to reach a local roofer who does these tear-offs.
What you have now
What a "silver roof" actually is
Most are built-up roofs: alternating layers of roofing felt and hot asphalt or coal tar, mopped down decades ago. Others are roll roofing, a heavier mineral-faced sheet nailed or cemented in place. The silver is aluminum roof paint, brushed or rolled on every few years to reflect sun and slow the tar from drying out.
For a long time that was the standard Philadelphia rowhome roof, and the standard fix for a worn one was to put another layer on top. That's why so many houses in South Philly, North Philly, Kensington, West Philly and the lower Northeast now have two or three roofs stacked up, with the oldest one sitting on the original boards.
How to tell how many layers you have
Look at the roof edge where it meets the gutter, or at the side of the roof hatch or skylight curb. Each roof shows as a separate band, like the rings in a tree. A roofer can confirm it with a small cut that gets patched right after.
Signs it's past recoating
Repainting buys time only while the tar underneath is still sound. Watch for:
- Silver peeling in sheets and showing black underneath
- "Alligator" cracking in the tar across the roof
- Blisters that come back after being patched
- Soft or springy spots when you step on it
- Leaks returning within a year or two of a recoat
- Two or more old roofs visible at the edge
Why layers matter
Why another layer usually isn't the answer
Each roof added on top hides what's happening below it. Water that gets between layers can sit there for years, soaking the old felts and slowly rotting the boards, while the top surface looks fine. The extra weight adds up too.
Building codes generally don't allow a new roof over two existing layers, so most silver-roof replacements start with a full tear-off. Even with only one old layer, taking it off is usually the better long-term choice: the roofer gets to see and fix the boards, and the new roof bonds to a clean, flat surface instead of an uneven old one.
Older materials: some very old roofing products, especially certain flashing cements and felts, can contain asbestos. If a roofer suspects it, it has to be tested and handled by a qualified contractor under city and state rules before tear-off. Ask about it if your roof has been on the house for many decades.
The work
What replacing a silver-coated roof involves
Set up & protect
Ladders or a chute go up, the house below is protected, and a dumpster goes in front. On the street it usually needs a city right-of-way permit.
Tear off to the boards
Every old layer comes off, down to the wood. Tar and felt are heavy, so this is the messiest and most labor-heavy part of the job.
Fix the boards
Rotted or broken boards are replaced. With the roof open, it's also the time to correct sags that have been holding water.
Insulate & re-roof
Insulation board goes down, sometimes tapered to improve drainage, then the new membrane and new flashing at walls, chimneys and the hatch.
Upgrade options
What can replace a silver-coated roof
Any of the three modern flat roof membranes is a big step up from tar and paint. The best choice depends on your roof and how you use it.
EPDM rubber
Large sheets with few seams, flexible through freeze-thaw winters, and straightforward to repair. A common choice for rowhome main roofs.
TPO
A white, heat-welded membrane that reflects summer sun. A good fit if the top floor has been uncomfortable under a dark roof.
Modified bitumen
The closest modern relative of a tar roof, but factory-made and far tougher. Handles foot traffic well where people walk to a deck or condenser.
Whatever the membrane, the tear-off is the chance to add insulation, build in better drainage with tapered boards or a new scupper, and redo the parapet flashing at the party walls properly instead of patching it again.
Planning your job
What affects the price
On a silver-roof replacement, most of the variation comes from what has to come off and what's found underneath:
- Number of old layers. Each extra roof means more tear-off labor, weight and disposal.
- The boards underneath. Rot usually shows up only once the old layers are off.
- Insulation and drainage. Adding insulation or tapered boards to fix ponding adds material and time.
- Which membrane. EPDM, TPO and modified bitumen differ in material and installation.
- Access and the dumpster. No rear alley and a narrow street mean hauling everything through the front.
- The back building. Doing the kitchen roof at the same time shares the setup and the dumpster.
- Special handling. Testing and abatement if older materials are suspected of containing asbestos.
Get a quick read on your roof with the Roof Problem Checker.
Related pages
- Flat roof coating: when a single sound layer can be coated instead
- Flat roof replacement: the full replacement process
- South Philly flat roof repair: blocks of layered silver roofs
- North Philly flat roof repair: older roofs and rotten boards
- Old silver-coat roofs: the short version in the roof guide
Party-wall tip: your neighbors' silver roofs will still be there after yours is replaced. Ask how the new membrane will be tied into theirs at each party wall, since that seam is where a new roof next to an old one usually leaks.
Silver-coated roof questions
Can't I just repaint the silver again?
If the tar underneath is still sound and there's only one layer, recoating can buy a few more years. Once it's cracking, blistering or leaking through fresh paint, more paint won't fix what's happening below the surface.
Can a new roof go right over my silver roof?
Sometimes over a single sound layer, but rarely over two, and building codes generally don't allow it over two existing roofs. Most roofers recommend tearing off so they can check the boards and give the new roof a clean, flat base.
How messy is a tear-off?
The roof work itself is outside, but the old layers are heavy and dusty. Expect a dumpster out front, noise for a day or two, and some grit in the top floor. Closing top-floor windows and covering anything stored in the attic or top-floor closets helps.
Will a new roof make my top floor cooler?
Often, yes, especially with a white TPO membrane or a white coating, and more so if insulation is added during the replacement. A dark tar roof absorbs a lot of summer heat right above the top-floor ceiling.
How long does a silver roof replacement take?
A typical rowhome main roof is usually torn off and replaced in one to two days, weather permitting. Extra layers, rotten boards or doing the back building at the same time can add time.
Have a different question about your silver roof? Call and ask a local roofer.
(215) 702-6130