Roof Restoration in Unionville, PA
Roof restoration is a real option for some roofs and a sales pitch for others. A slate roof with sound stone, a metal barn roof with surface rust, or a flat roof that is still watertight can often be renewed for years at a fraction of replacement cost. A worn-out shingle roof cannot. We tell you honestly which one you have, and restore only the roofs that are worth it.
- Slate re-securing and copper flashing renewal
- Metal roof re-screwing, rust treatment and recoating
- Flat roof coatings over sound membranes
- Low-pressure moss and algae cleaning
Water coming in right now? Call and tell us if a tree or limb is on the roof. We will walk you through the next hour.
Call (610) 817-4457Roof restoration means renewing the parts of a roof that wear out first, such as flashing, fasteners, coatings and surface growth, so a roof whose main material is still sound keeps working for years longer. It suits slate, metal and many flat roofs. It does not suit asphalt shingles that are brittle, curling or bare of granules, which need replacement.
On this page
- What roof restoration is, and what it is not
- Is your roof a good restoration candidate?
- Slate roof restoration
- Metal roof restoration
- Flat roof restoration coatings
- Asphalt shingle roofs: what restoration can and cannot do
- Moss and algae: cleaning a roof safely
- Cedar shake roof care
- Why restoration timing matters in Chester County
- How a roof restoration works with us
- What roof restoration costs compared with replacement
- Ventilation and drainage: the quiet part of restoration
- Restoration on historic Unionville homes
- Restoring a roof before you sell
- Keeping a restored roof in good shape
- Questions to ask before you pay for restoration
- Questions homeowners ask
What roof restoration is, and what it is not
You will hear "roof restoration" used for very different things. Some contractors use it for real, durable work. Others use it to sell a spray-on product to owners of roofs that actually need replacing. Here is the honest version.
Restoration is
- Renewing flashing, fasteners and details on a roof whose main material is sound
- Re-securing slipped slates and replacing broken ones
- Treating rust and recoating metal that has not rusted through
- Coating a flat roof membrane that is still watertight, over dry insulation
- Safely cleaning moss and algae and preventing regrowth
- Correcting ventilation and drainage that have been shortening the roof's life
Restoration is not
- A coating sprayed over brittle, curling or bare asphalt shingles
- Sealing over wet insulation or rotted decking
- Tar or sealant smeared over slate or flashing
- Pressure washing a shingle roof to make it look new
- A way to avoid replacement on a roof that has reached the end of its life
The test is simple: is the main roofing material still sound? If yes, restoration can be excellent value. If no, it only delays a replacement and costs money twice.
Is your roof a good restoration candidate?
| Roof | Good candidate if | Poor candidate if |
|---|---|---|
| Slate | Slates ring when tapped; problems are slipped pieces and flashing | Slate flakes and sounds dull across whole slopes |
| Metal panels | Surface rust only; fasteners and seams are the problem | Rust holes in many panels; purlins rotted |
| Standing seam or flat-seam metal | Seams and paint are the problem; metal is solid | Metal rusted through in many places |
| Flat membrane | Watertight with good adhesion; insulation dry | Widespread wet insulation; ponding for days; rotted deck |
| Asphalt shingles | Granules intact; shingles bend without cracking | Curling, cracking, bare spots, leaks in several places |
| Cedar shake | Most shakes solid; damage limited | Shakes soft, eroded thin or cupped across large areas |
Slate roof restoration
Slate is the best candidate for restoration because the stone often outlasts everything around it. The National Park Service notes that properly installed slate roofs last 60 to 125 years or longer depending on the slate, and that the first commercial slate quarry in the United States opened in Peach Bottom Township, Pennsylvania, in 1785 (National Park Service). Hard Pennsylvania slates such as Peach Bottom can last far longer than soft Bangor-area slate, which often reaches the end of its life between 70 and 110 years (HistoricBldgs.com).
A slate restoration typically includes:
- Replacing broken, missing and badly delaminated slates with matched stone
- Re-securing slipped slates with slate hooks or copper nail and bib repairs
- Renewing chimney, dormer and wall flashing in copper, with counter flashing cut into mortar joints
- Replacing rusted valley metal with copper or other long-life metal
- Removing old tar patches and face-nailed repairs
- Resetting or rebuilding ridges and replacing snow guards
- Relining built-in gutters
On many Unionville homes built between 1820 and 1880, this kind of work keeps the original roof, and the character it gives the house, for decades more.
Metal roof restoration
Metal roofs on barns, garages, porches and older homes are strong candidates when the panels are sound and the problems are fasteners, seams and coatings.
- Re-screwing. Replacing dried-out washers and backed-out screws across an exposed-fastener roof stops many small leaks at once.
- Rust treatment. Cleaning surface rust, treating it, and priming bare metal before it rusts through.
- Seam and lap sealing. Sealing open laps on panel roofs, and resoldering or repairing seams on flat-seam and standing seam metal.
- Recoating. A coating system made for metal roofs can renew weather protection and appearance once the surface is properly prepared.
- Flashing and trim. Replacing loose or rusted ridge caps, eave trim and wall flashing.
If panels have rusted through in many places, or the purlins and framing are rotted, new panels make more sense than coatings.
Flat roof restoration coatings
Coatings can add years to an aging low-slope roof, but only under the right conditions.
| Condition | Coating a good idea? |
|---|---|
| Membrane still watertight, good adhesion, dry insulation | Often yes |
| A few failed seams or details, otherwise sound | Yes, after those are repaired |
| Areas of wet insulation | Only after wet areas are cut out and replaced |
| Ponding water that lasts days | Not until drainage is corrected; the NRCA standard is no ponding 48 hours after rain under drying conditions |
| Widespread membrane failure or a rotted deck | No; replacement is needed |
Ponding standard: Professional Roofing (NRCA).
A proper coating job starts with cleaning, repairing seams and flashing, replacing any wet areas, and priming where the coating system requires it. Skipping those steps is why some coatings peel within a few years.
Asphalt shingle roofs: what restoration can and cannot do
Asphalt shingles wear out as a whole. Sun breaks down the asphalt, granules wash away, and the shingles become brittle. No product turns a worn-out shingle roof back into a new one.
What does help a shingle roof that still has life left:
- Targeted repairs. Replacing wind-damaged shingles, cracked pipe boots, worn ridge caps and failed flashing.
- Ventilation. Balancing soffit intake and ridge exhaust reduces heat and moisture that age shingles early.
- Safe cleaning. Removing moss that holds moisture against the shingles.
- Gutter and drip edge fixes. Keeping water moving off the roof edge.
Some companies sell spray-on shingle treatments that claim to extend shingle life. Long-term evidence varies, and they do not repair damage. If you are considering one, ask your shingle manufacturer whether it affects your warranty first.
Moss and algae: cleaning a roof safely
Unionville's wooded lots and shaded north slopes are ideal for moss and the dark streaks caused by roof algae. Algae streaks are mostly cosmetic; the Canadian Asphalt Shingle Manufacturers' Association notes that algae staining is not a sign of a shingle defect (CASMA). Moss is different: it holds moisture against the roof, lifts shingle edges and clogs gutters.
How to clean without damaging the roof
- No pressure washing. The Asphalt Roofing Manufacturers Association says high-pressure washing should not be used for algae removal, noting its effect is only temporary and discoloration is likely to recur (ARMA via Inman). High pressure strips the granules that protect shingles from sun.
- Gentle chemical cleaning. ARMA's guidance is that algae can be lightened by gently applying a solution of chlorine bleach, trisodium phosphate and water, with ratios that vary by shingle manufacturer.
- Protect plants. Wet landscaping first and rinse it after, because cleaning solutions harm plants.
- Remove moss gently. Loosen it with a soft brush working down the slope, never prying up shingle edges.
- Prevent regrowth. Zinc or copper strips near the ridge can help inhibit new growth, though opinions vary on how well they work. Trimming overhanging branches to let in sun helps most.
Cleaning solutions make roofs slippery. This is work for someone with proper fall protection, not a ladder and a garden sprayer.
Cedar shake roof care
Cedar shake roofs last longest when they can dry out. Restoration work includes clearing debris from between shakes, removing moss, replacing split and missing shakes, renewing flashing, and trimming trees to let sun and air reach the roof. Shakes that are soft, cupped or eroded thin across large areas are at the end of their life.
Cedar near the end of its life often shows split shakes along the eaves first, where water and ice are hardest on the wood.
Why restoration timing matters in Chester County
Chester County roofs face freeze and thaw cycles, ice at the eaves, summer thunderstorms and strong winds. PECO's 2026 filings with the Pennsylvania Public Utility Commission blamed heavy winds for storms on February 22, March 16 and May 20 that cut power to thousands of county customers (March filing).
That weather is exactly what turns a roof that could be restored into one that has to be replaced. A slipped slate lets water rot the sheathing beneath it. A loose metal panel tears off its neighbors in the next gust. A small opening in a flat roof seam soaks the insulation over a winter. Restoration works best done early, while the main material is still sound.
Late summer and early fall are usually the best window: dry weather for coatings and flashing work, and the roof is ready before winter. Many coatings also need minimum temperatures to cure properly.
How a roof restoration works with us
- Assess the main material. We check whether the slate rings, the metal is sound, the membrane is watertight, or the shingles still have life. This decides everything else.
- Check what is underneath. Attic or interior checks for decking rot, wet insulation and past leaks.
- Written recommendation. Restoration, targeted repair, or replacement, with the reasoning, photos of every slope, and a written price.
- Repair before renewing. Failed flashing, seams, fasteners and broken pieces come first.
- Renew and protect. Coatings, cleaning, ventilation and drainage improvements as the roof needs.
- Document. Before and after photos, and notes on what to watch in coming years.
What roof restoration costs compared with replacement
Restoration costs depend on the roof type and how much needs renewing. National 2026 benchmarks: typical roof repairs run about $400 to $1,900, slate repairs $700 to $3,000, flat roof repairs $300 to $1,100 and flashing repairs $150 to $1,000 (Fixr; HomeAdvisor). A full slate restoration with new copper flashing at several chimneys and valleys can run well above those figures.
Compare that with replacement. This Old House puts a typical Pennsylvania roof replacement at $5,740 to $19,078 in 2026 (This Old House), and natural slate averages about $20 per square foot installed (Fixr). For a sound slate roof, restoration is usually a fraction of replacement. Fixr also notes that when slate repairs approach 50% or more of a new roof's cost, replacement may be the smarter choice.
Ventilation and drainage: the quiet part of restoration
Some of the most valuable restoration work happens off the roof surface. Attic heat and trapped moisture age shingles and decking from below, and water that lingers at edges and valleys wears roofs out from above.
- Balanced attic ventilation. The International Residential Code sets minimum attic vent area at 1/150 of the attic floor area, or 1/300 when intake and exhaust are balanced as the code describes. Clearing blocked soffit vents and adding exhaust where needed helps any roof last longer.
- Bath fans and dryer vents. Making sure they exhaust outside, not into the attic, reduces winter condensation that rots decking and nails.
- Gutters and downspouts. Correct pitch and clear outlets keep water off fascia and away from foundations.
- Drip edge. Adding it at eaves where it is missing keeps water off the fascia.
- Flat roof drains. Clearing and correcting drains and scuppers stops ponding that shortens membrane life.
Restoration on historic Unionville homes
The Unionville Village Historic District, listed on the National Register in 1979, includes 69 contributing buildings, the oldest dated to about 1750. For homes like these, restoring the original roof keeps both the weather protection and the character that makes the house valuable. The National Park Service's Preservation Brief 29 recommends documenting a historic slate roof's colors, shapes, patterns and details before work, so repairs preserve its appearance (Preservation Brief 29).
Restoring a roof before you sell
A buyer's inspector will look hard at the roof, and an older roof can become a bargaining point. If your roof is sound but worn in places, a restoration before listing, with photos and a written report, can show buyers the roof has been cared for. For slate and other long-life roofs, documentation of the stone's condition and new flashing can be more persuasive than a new roof would be. If the roof truly needs replacement, it is better to know before the inspector tells the buyer.
Keeping a restored roof in good shape
- Look over the roof from the ground each spring and fall, and after major storms
- Clear gutters, valleys and flat roof drains after leaf drop
- Keep branches trimmed back from the roof
- Keep foot traffic off slate and coated surfaces
- Fix small problems, such as a slipped slate or a loose screw, as soon as you see them
- Recoat metal and flat roofs on the schedule the coating system calls for
Questions to ask before you pay for restoration
- Is the main roofing material still sound, and how did you check?
- What repairs will be done before any coating or treatment?
- Will you check for wet insulation or rotted decking first?
- How long should this restoration last, and what maintenance does it need?
- Does this affect my manufacturer's warranty?
- Would you recommend replacement instead, and why or why not?
Pennsylvania requires home improvement contractors to register with the Office of Attorney General, put the number on a written contract for jobs over $500, and limit deposits on jobs over $1,000 to one-third of the price plus special order materials (HICPA information sheet).
Roof restoration questions
Is roof restoration worth it?
It is worth it when the main roofing material is still sound, such as hard slate, metal with only surface rust, or a watertight flat membrane. It is not worth it on asphalt shingles that are brittle, curling or bare.
Can you restore an old asphalt shingle roof?
You can extend the life of a shingle roof that still has life left with targeted repairs, ventilation and cleaning. No product restores shingles that are worn out; those need replacement.
Should I pressure wash my roof?
No. The Asphalt Roofing Manufacturers Association advises against high-pressure washing for algae removal because it is only temporary and can strip the protective granules from shingles.
Are the black streaks on my roof damaging it?
Algae streaks are mostly cosmetic and are not a sign of a shingle defect, according to CASMA. Moss is more harmful because it holds moisture and lifts shingle edges.
Can a coating fix my leaking flat roof?
Only after the leaks are repaired, wet insulation is replaced and drainage is corrected. A coating protects a sound membrane; it does not fix a failing one.
How long does slate restoration last?
On hard slate with new copper flashing, the restoration can last as long as the stone, often decades. Soft slate near the end of its life may not justify major restoration.
Can you restore a rusty metal barn roof?
Yes, if the panels have surface rust but no holes. Re-screwing, rust treatment and a metal roof coating can add years. Panels rusted through need replacement.
What about shingle rejuvenation sprays?
Long-term evidence varies and they do not repair damage. Ask your shingle manufacturer whether a treatment affects your warranty before using one.
How much does roof restoration cost?
It depends on the roof. National 2026 repair benchmarks run from a few hundred dollars for small work to several thousand for slate, and restoration is usually a fraction of replacement on a sound roof.
What are your hours?
We answer Monday to Saturday, 8:00 am to 8:00 pm, and are closed Sunday. Call (610) 817-4457.
Related roofing services
Find out if your roof is worth restoring
Tell us what the roof is made of, roughly how old it is, and what you are seeing. We will inspect it and tell you plainly whether restoration, repair or replacement is the better investment.
- Phone
- (610) 817-4457
- Address
- 850 Unionville Road, Kennett Square, PA 19348
- Hours
- Monday to Saturday, 8:00 am to 8:00 pm. Sunday closed.
- Service area
- Unionville, East Marlborough Township and nearby communities in 19375, 19348, 19382, 19366, 19317 and 19320
Water coming in right now?
Keep people out of rooms with sagging ceilings, catch the water, and call. If a limb is on power lines, call PECO at 1-800-841-4141 first.
Planning a repair?
Send a photo of the roof or the ceiling stain. We inspect, then give you a written estimate with photos of every problem we find.