Most houses around Elizabeth have a simple gable roof. Some don't. Older streets in the city and in towns like Cranford and Rahway include houses with roofs shaped very differently: steep slopes that almost look like walls, roofs with a bend partway down, or many small slopes meeting at odd angles. These roofs look distinctive, and they ask more of a roofer.
Mansard Roofs
A mansard roof has a nearly vertical lower slope on each side, often with dormer windows set into it, and a flatter top section. Many older mansards in the region were built in the late 1800s.
Where they leak:
- the joint where the steep lower slope meets the flat or low top
- around the dormer windows set into the steep slope
- the flat top, which often has its own membrane and drains
Gambrel Roofs
A gambrel has two slopes on each side: a steep lower section and a gentler upper one, like a barn. Dutch colonial houses commonly use this shape.
Where they leak:
- the bend where the two slopes meet
- dormers set into the lower slope
- the ends, where the shape meets the gable walls
Steep and Cut-Up Roofs
Victorian-era houses, and some later revival styles, have steep roofs with many valleys, turrets or gables. Every valley is a channel for water, and every joint is a place for flashing to fail.
What These Roofs Need
- A crew that works steep roofs. Not every company does. Ask.
- Careful flashing at every change in slope. The transition between a steep and a low section is the most common leak point.
- The right material for each section. A mansard's flat top may need a membrane, while its sides take shingles or slate.
- Time. These jobs take longer and cost more per square than a simple gable.
Gutters and Ice on Steep Roofs
Steep roofs move water fast. In a heavy rain, water can shoot past a gutter instead of landing in it, soaking the ground at the foundation and splashing back onto siding. On a gambrel or mansard, the lower slopes are close to vertical, so gutters have to be sized and placed with that speed in mind. In winter, snow slides off steep slopes in sheets and can tear gutters loose or land on porch roofs below. Snow guards, sturdier gutter hangers, and an ice barrier at the eaves help. Ask the roofer to look at the gutters and the roofs below the steep slopes while they're planning the main job.
Matching the Look
Owners of older houses often care how a new roof looks from the street. Architectural shingles come in shapes and colors meant to suggest slate or wood. On a mansard or a Victorian, ask to see samples on a sunny day and a cloudy one before you choose, and ask how the new material will be finished at the decorative trim along the edges.
Slate and Older Materials
Some of these houses still have slate or older materials on parts of the roof. A roofer can tell you whether the slate can be repaired, or whether a replacement material is the practical choice.
Questions
Why do mansard roofs leak at the top?
The low top section drains slowly and meets the steep sides along a long edge. If that edge isn't detailed well, water gets in.
Can a gambrel roof use regular shingles?
Yes, on both slopes, with careful flashing at the bend.
Do historic districts limit what I can use?
Some towns have historic districts with rules for exterior changes. Check with your town before choosing materials. Permits for the work itself follow the state code run by the NJ Department of Community Affairs.
Around Elizabeth
Older, unusual roofs show up in Cranford, Rahway and Elmora Hills. Shingle work is covered on shingle roofs.
Cape Cod Roofs: Dormers, Knee Walls and Hot Upstairs Rooms
Why Capes leak where they do, and run hot in summer.
Wind Off the Bay: Shingle Wind Ratings and Nailing
What the numbers on the bundle mean in a nor'easter.