Why Older Philly Row Homes Experience More Winter Leaks

Philadelphia is known for its quaint row homes, many of which are at least a century old. It’s no surprise that it’s the first city in the US that the OWHC named as a “World Heritage City.”  That said, this exact heritage makes them particularly vulnerable to the intrusions of winter. As the temperature drops and snow keeps coming, owners of row homes need to take steps to prevent leaks from appearing. 

Why Older Row Homes Are Vulnerable

Old Philly row homes are vulnerable for various reasons, mostly due to construction and environmental factors. Here are the most common causes for winter leaks: 

1. Aged Roofing and Flashing

Almost all row houses in Philadelphia were built in the mid-20th century. Very few replaced those roofs altogether. Over time, the roofing materials deteriorated, allowing the melted snow to seep into the porous walls. Professionals at Umbrella Roof recommend you have old Philly row homes inspected at least once a year to check for wear and tear. Find out more details about correct Philly row home maintenance at umbrellaroof.com. 

2. Frequent Freeze-Thaw Cycles

Philadelphia has the kind of weather that’s not just cold, but deceptive. This is particularly true in recent times, where it can go below freezing one week and move into “mild spring weather” the other. When water enters the old shingles and flashing and then freezes, those particles will expand and create micro-cracks that lead to the following issues: 

• Curled or visibly cracked shingles
• Weakened roof decks
• Worn underlayment
• Loose flashing around the vents and chimneys

The longer this happens, the higher the wear will be on the roof. Eventually, it seeps into the walls and causes all types of other problems.

3. Ice Dam Formation

Ice dams are common in Philly because heat escapes from the attic, melting the snow on the roof. The water then starts flowing, but the low temperature causes it to re-freeze once it reaches the eaves. Eventually, it creates a ridge that keeps water from flowing off the roof. With nowhere else to go, it backs up underneath the underlayment and shingles, causing leaks in your home.

4. Lack of Modern Insulation

According to Philly local data, while new houses meet energy-saving standards of modern times, most of its rowhouses are poorly insulated. When this happens, all the warmth from the attic rises through the roof and unevenly melts the snow. Plus, the lack of insulation contributes to mold formation, as it worsens moisture. With time, mold compromises the roofing materials, which leads to more leaks.

5. Shared Walls

The shared walls can be a blessing for keeping your home warm, because you’re also benefiting from your neighbor’s heating. The problem is that if said neighbor did not maintain their roof, all their roofing problems can “leak” back to you. This is especially the case when the roof has a slight slope that sends water your way. If the flashing fails or they don’t take care of the ice dams, your old row house becomes vulnerable.

Tips to Prevent Winter Leaks in Philly Homes

Winter leaks can happen to anyone, especially after storms or heavy snow. However, you can protect your roof from winter leaks by taking some proactive steps. This should especially be the case if you have an old home. Here are some things to add to your maintenance checklist:

• Clean your gutters and downspouts, especially in late fall
• Insulate your attic effectively to prevent moisture
• Conduct post-storm roof inspections to catch potential issues
• Have an ice and water shield installed underneath the shingles
• Seal gaps and fix loose shingles the moment you notice them
• Install some heat cables if the ice dams keep happening

Philly row homes usually have roofs that are meant to last, but they’re not safe from aging and storm damage. Make sure to get them regularly inspected for hidden damage.

The Bottom Line

The historic significance and multitude of old row houses make Philadelphia a charming place to visit. Still, homeowners must be aware of potential roofing weaknesses to be protected from leaks. Make sure to get your inspections and address the issue before winter truly sets in!