Older farmhouses and attached rowhouses need more checking than a newer subdivision house. Expect questions about how many layers are already on, the condition of the deck underneath, valleys and chimneys, and the flashing along shared walls. Ask a roofer to look at those before quoting, because they drive the price and the method.
Key takeaways
- Souderton Borough counts about 2,100 homes, and about 30 percent were built before 1939, with about 37 percent more from the 1940s to 1960s. Those two groups are where deck and layer questions come up most.
- About 24 percent of the borough's homes are attached row or twin houses and about 22 percent are duplexes or small apartment buildings, so shared walls and shared roof edges are everyday work here.
- Farm-origin areas such as Harleysville and Franconia, settled by Pennsylvania Dutch farmers, have large, complicated roofs on houses and outbuildings, often with several layers, valleys and chimneys (a general pattern, not a count).
- Flashing at chimneys, valleys and party walls usually fails before the shingles do, and it is cheaper to renew while the roof is open than to chase leaks later.
- Very old shingle or siding materials near Ambler, where an asbestos shingle factory operated from 1883, are a reason to ask any roofer how they handle unknown old material. Never assume a given roof does or does not contain it.
- Ask the borough or township what permit applies before the job, and look up the contractor's Pennsylvania registration.
Why do old farmhouse and rowhouse roofs need different treatment?
They have more history. Older roofs may carry several layers of shingles, original wood decking with gaps or soft spots, complicated shapes with valleys and dormers, and flashing built into brick or stone. Each one can hide a problem that a simple newer roof does not, so the inspection matters more than the shingle.
Souderton was chartered as a borough in 1887, when about 600 people lived here. By 1910 the population was 1,875, and by 1930 about 4,000. Houses went up fast along those streets, and many were roofed more than once in the century and more since. Borough figures put about 30 percent of homes before 1939 and about 37 percent in the 1940s to 1960s.
That age shows up above the ceiling. A roof that has been patched, overlaid and patched again has a different structure from one that is new. The question is not whether an old roof is bad, but whether anyone knows what is under the surface, and the honest answer is often only after the old covering comes off.
A roofer working on an older house will usually want to see the attic as well as the outside. Daylight through the boards, dark stains on the rafters, or sag between them tells more than the shingles ever will. If you are weighing a repair against a full job, roof repair and roof replacement set out where the line usually falls.
How many layers of roofing can an old house have, and why does it matter?
Older houses often carry more than one layer because a new roof was laid over the old. Extra layers add weight, hide deck damage and can make the job a full tear-off. Ask the borough or township what the local code allows, and ask the roofer to count the layers at an edge before quoting.
A layer is a full course of shingles. A homeowner a generation ago may have chosen to lay new shingles over old ones rather than pay for a tear-off. Older farmhouses with many decades of owners are the likeliest to have several, though that is a general pattern, not a number anyone has counted for the area.
More layers matter for three reasons. They add weight to rafters that were sized for lighter loads. They trap heat and moisture. And they can hide soft or rotted decking until it is too late to fix it cheaply. A tear-off lets a roofer see and repair the deck before the new roof goes on.
Code on layers is a local question. The borough or township building office, working under the Pennsylvania Uniform Construction Code, can say what applies to your address, so ask them rather than rely on a rule of thumb. For Souderton Borough, the borough site says permits are applied for at the borough office and no work starts without an approved permit.
- Ask the roofer to check at an eave or rake edge, where the layers show in cross-section.
- Ask what happens if the deck is soft or gapped once the old roof is off.
- Ask how the old material will be removed and hauled away.
- Ask whether the quote assumes tear-off or an overlay, and why.
What is different about a rowhouse or twin roof?
Attached houses share walls, and often the roof edge, with the neighbor. That means flashing where the roof meets the party wall, access that crosses another property, and drainage that may be shared. Work on your half can touch the other half, so tell the neighbor early and ask the roofer how they handle the seam.
Row houses and twins make up a large share of the borough's homes: about 24 percent are attached row houses and about 22 percent are duplexes or small apartment buildings, and about 14 percent are large apartment buildings. Lansdale and Norristown have the same kind of dense, older housing, and many of the roofs are flat or low-slope where one house meets the next.
The party wall is the weak spot. Where the roof meets the shared masonry wall, flashing has to be stepped into the brick or stone and sealed. Over decades, mortar crumbles, sealant dries out and water slips in at the seam. It is usually the first place a leak shows up on an attached house.
Access matters too. A roofer may need to cross a neighbor's roof or yard, hoist material over a shared wall or work from a narrow lane. That is a conversation to have before the day, not on it. See flashing repair and flat and low-slope roofing for what these jobs involve.
What should you know about valleys, chimneys and outbuildings on a farm property?
Farm properties tend to have large, complex roofs on houses, barns and sheds, with many valleys, dormers and chimneys. Each valley and chimney is a place water can get in. A roofer should price them one by one rather than as a single square-footage number, and should ask about the outbuildings you want covered.
Harleysville was settled in the 18th century by Pennsylvania Dutch farmers and merchants, and Lower Salford Township was created in 1741. Franconia Township dates to the late 1720s and was originally farmland. The farmhouses and outbuildings that remain have large roof areas next to newer developments, a pattern that is true of the region rather than a fact about any one house.
Valleys collect the water from two slopes, so they carry more flow than any other part of the roof. Chimneys interrupt the roof and need flashing on all four sides, plus a cricket on the uphill side of a wide one. On an old stone or brick chimney, mortar loses ground over many freeze-thaw winters, and the flashing may be set into joints that are crumbling. The roofer should look at the chimney itself, not just the metal around it. See chimney flashing and repair.
Outbuildings raise a different question: is a barn or shed roof worth the same treatment as the house? Sometimes a simple metal panel roof suits an outbuilding better than shingles, and our shingle, metal or slate guide compares those choices. Tell the roofer which buildings you want priced so the quote is clear.
What about asbestos, old materials and slate near Ambler and other old town cores?
Very old roofing and siding can contain materials that need careful handling, and nobody can tell by looking. Ask any roofer how they treat unknown old material, and whether testing is advised before a tear-off. Old slate is a separate skill: it is repaired by hand, not nailed over like shingle.
Ambler has an unusual history. Keasbey and Mattison opened a factory there in 1883 and made asbestos shingles marketed as fireproof and weatherproof, and the firm was sold to Turner and Newall in 1934. That history is why a tear-off of very old shingle or siding in the area can raise questions. It does not mean any particular roof contains asbestos, and you should not assume it does or does not. Only testing settles it.
A responsible roofer will tell you what they would do if they met a suspect material, and will not rush you past the question. If you are told something is safe or unsafe on sight alone, treat that as a reason to ask for more detail.
Slate and heavy tile are different again. Quakertown and Doylestown have 19th-century town cores where older buildings may carry slate or heavy multi-layer roofs, though that is a general pattern. Slate is repaired by lifting individual pieces and replacing or sliding in new ones, which is slow, skilled work. The slate and historic roof repair page covers it.
What should you ask before an old-house roofing job starts?
Ask what is under the old roof, how the deck will be checked, how valleys, chimneys and party walls will be flashed, who pulls the permit and what happens if hidden damage is found. Get the answers in writing, with photographs, and confirm the contractor's Pennsylvania home improvement registration before signing.
A fixed quote on an old house can only be as firm as the information behind it. Many roofers will quote a price for the visible work and a stated rate for hidden damage found at tear-off, such as extra decking. Ask how that works before the job, so a soft deck does not become a surprise argument.
The table lists the items that most often move an old-house roof price and what to ask about each. It does not give prices, because there are no sourced local ones, and the Pennsylvania-wide figures in our cost guide are a starting point only.
| Item | Why it affects the job | What to ask |
|---|---|---|
| Existing layers | More layers mean more removal and weight | How many are there, and does the quote assume tear-off? |
| Deck condition | Soft or gapped boards must be replaced or fixed | How is hidden deck damage priced and agreed? |
| Valleys and dormers | More cuts and more places for water to enter | How will each valley be flashed? |
| Chimney | Flashing and mortar fail with age | Will the chimney be checked, not just re-flashed? |
| Party wall or shared edge | Masonry flashing and neighbor access | How will the seam be sealed, and how will access work? |
| Unknown old material | May need testing or special handling | What is your approach to suspect material? |
| Permit | Local office decides what applies | Who applies, and is it in the quote? |
Frequently asked questions
Can I put new shingles over my old farmhouse roof to save money?
Sometimes a second layer is allowed, but it hides deck damage, adds weight to older rafters and can shorten the new roof's life. Ask the borough or township what its code allows, and ask a roofer to check the existing layers and deck before you decide between an overlay and a tear-off.
Who is responsible for a shared roof edge between two rowhouses?
It depends on the deeds and any agreements between neighbors, and a roofer cannot settle that. What a roofer can do is explain what the work will touch on each side. Talk with your neighbor early, and ask your borough office whether permits or notices apply to shared walls.
Does a pre-1939 house always need a full tear-off?
No. Some roofs can be repaired in sections if the deck and shingles are sound. A roofer has to see the attic and the roof edges to judge. A tear-off becomes likely where layers are stacked, the deck is soft, or flashing is failing across much of the roof.
How do I know if my old shingles contain asbestos?
You cannot tell by looking. Ambler once had an asbestos shingle factory, so the question comes up in the area. Ask your roofer how they handle unknown old material and whether testing is advised before a tear-off. Do not break, sand or cut old material yourself.
What if the roofer finds rotted decking once the old roof is off?
Ask before the job how hidden damage is handled. Many roofers quote a rate for replacing bad boards, so the price changes only by what is found. Have the roofer show you photographs of what they found, and agree on any extra cost in writing before the work continues.
Sources
- Souderton Borough: History of Souderton
- Souderton Borough: Building and repair permits
- Wikipedia: Ambler, Pennsylvania
- Wikipedia: Harleysville, Pennsylvania
This guide is general information for Montgomery County homeowners, not a substitute for an on-site inspection. Prices are estimates. See our disclaimer.