If you are planning a major home renovation that involves adding more living space under the roof, improving energy performance, or upgrading your roofing system, you are likely facing the same questions that homeowners and builders grapple with every day. From installing full-width dormers on brick houses to insulating vaulted ceilings and managing drainage on flat rubber roofs, the details matter tremendously. This article draws on real-world building experience to help you make informed decisions about these challenging but rewarding projects. For a deeper look at one of these topics, our cathedral ceiling insulation guide covers the full technical breakdown of air-sealing and insulating unvented roof assemblies.
Greedy Dormers: Adding Full-Width Second-Floor Space to Brick Homes
A “greedy dormer” is the colloquial term for a dormer that runs the full width of a house, effectively transforming a partial upper floor into a full second story. While the concept sounds straightforward, executing it on a brick masonry house presents unique structural challenges that require careful planning.
Structural Considerations for Full-Width Dormers
When you expand a shed dormer to the full width of a house, the dormer walls must bear on the existing exterior walls. In a wood-frame house, this is relatively simple: you nail a sill plate to the top plate and build upward. However, when the existing gable ends are solid brick masonry, the approach changes completely.
- Load path verification: The new dormer walls will impose significant vertical loads on the brick walls below. An engineer must verify that the existing foundation and masonry walls can support these additional loads. Older brick walls were often designed for much lower loads than modern codes require.
- Attachment method: You cannot simply nail a wooden sill plate to a brick wall. Instead, you need to create a level bearing surface, typically by grinding or parging the brick to a uniform plane, then drilling and epoxying threaded rods into the masonry to secure the sill plate with nuts and washers.
- Lateral stability: The new dormer creates a different roof geometry that changes wind load paths. Diaphragm action of the roof sheathing must be tied back into the masonry walls through properly designed connections.
How to Attach New Roof Framing to Solid Brick Walls
Attaching new roof framing to existing brick masonry requires a systematic approach. The brick itself is rarely structural in modern terms, it is often a veneer or a single wythe of a cavity wall system, so connections must engage the structural backup or be designed to distribute loads across multiple wythes.
The recommended process begins with exposing the brick at the bearing location and inspecting for cracks, spalling, or deteriorated mortar. Any damaged masonry must be repaired or replaced before proceeding. Once the bearing surface is sound, a continuous steel angle or a pressure-treated sill plate is anchored using expansion anchors or epoxy-set threaded rods at 16-inch on-center spacing. The new rafters or trusses bear on this plate and are tied to it with hurricane ties or custom-fabricated strapping.
It is also critical to address the change in roof pitch. When a steep 7/12 gable roof meets a shallower 3/12 dormer roof, the transition creates a valley that must be flashed meticulously. Ice and water shield should extend at least 24 inches up both roof planes, and metal flashing at the valley should be woven into the shingle courses for a watertight installation. For more on the aesthetics and design possibilities, see our article on dormer design and architecture.
Cathedral Ceiling Insulation: Retrofitting Vaulted Ceilings with Spray Foam
One of the most common comfort complaints in homes with vaulted ceilings is persistent temperature stratification: the second floor or cathedral ceiling room is noticeably colder in winter and hotter in summer than the rest of the house. This is almost always a symptom of inadequate or improperly installed insulation in the roof assembly.
Open Cell vs Closed Cell Spray Foam for Vaulted Ceilings
Spray polyurethane foam (SPF) is the preferred solution for insulating unvented cathedral ceilings because it simultaneously provides thermal resistance, air sealing, and in the case of closed cell foam, a vapor retarder. The choice between open cell and closed cell depends on your climate zone, existing roof construction, and project goals.
| Property | Open Cell Spray Foam | Closed Cell Spray Foam |
|---|---|---|
| R-value per inch | R-3.5 to R-4.0 | R-6.0 to R-7.0 |
| Vapor permeability | Permeable (vapor open) | Impermeable (Class II vapor retarder) |
| Air sealing | Excellent | Excellent |
| Typical minimum thickness | 5 to 7 inches | 3 to 4 inches |
| Best suited for | Mixed-humid and cold climates with careful interior vapor control | Cold climates, hot-humid climates, and shallow rafter bays |
| Roof deck temperature | Stays closer to interior temperature | Warmer in winter (reduces ice dam risk) |
Roof Inspection and Maintenance After Spray Foam Installation
A common concern among homeowners is how to detect roof leaks after spray foam has been applied directly to the underside of the roof sheathing. This is a valid concern, and it requires a shift in maintenance strategy. Since the foam bonds directly to the deck, a small leak may go undetected for longer because water cannot travel laterally along the sheathing the way it would in a vented roof assembly.
The solution is a regimen of annual roof inspections. Twice per year, ideally in spring and fall, inspect the roof surface for damaged, lifted, or missing shingles; cracked or separated flashing at chimneys, vents, and valleys; and any signs of ponding water on low-slope sections. Address issues immediately rather than deferring them. Some contractors also recommend installing leak detection sensors at strategic points in the roof assembly during the initial construction to provide early warning of moisture intrusion.
If you are planning other second-floor renovations at the same time, such as moving plumbing vent stacks or reconfiguring bathroom exhaust ducts, complete those projects before the spray foam is installed. Poking holes through a continuous air-sealing layer to add new vents later compromises the performance of the insulation system. For a complete technical reference on this topic, consult our spray foam insulation technical guide.
Gutters and Drainage for Flat EPDM Roofs
Flat roofs and low-slope roofs present unique drainage challenges. When a flat porch or sunroom roof is covered with EPDM rubber membrane, the gutters must be designed and installed differently than on a standard sloped roof.
Hidden Gutter Solutions for a Clean Roofline
Many homeowners want the roof edge to look clean and modern, without exposed gutters breaking the visual line. A hidden gutter system, also called a concealed gutter or a built-in gutter, achieves this by incorporating the drainage channel behind the fascia rather than hanging it below the roofline.
The most effective approach for an EPDM roof is to install a continuous aluminum or copper gutter that is concealed behind a metal fascia. The EPDM membrane extends over the roof edge and terminates into this concealed gutter instead of hanging over the edge. This keeps the drainage system hidden while still providing the capacity needed for heavy rainfall. Key installation details include:
- The gutter should be sized for the local 100-year rainfall intensity, typically 5-inch or 6-inch half-round or K-style gutters with appropriate downspout sizing.
- A metal drip edge or gravel stop should be installed at the roof perimeter before the EPDM is applied, ensuring a clean termination point.
- The concealed gutter should have a minimum 1/8-inch per foot slope toward downspouts, even though the roof itself may be dead flat.
- Leaf guards or gutter screens are strongly recommended because concealed gutters are more difficult to clean than standard exposed gutters.
EPDM Roof Installation Best Practices for Durability
EPDM is a durable, flexible synthetic rubber membrane that performs exceptionally well on low-slope residential roofs when installed correctly. The membrane thickness should be a minimum of 45 mils for residential applications, with 60 mils recommended for areas subject to foot traffic or hail. Proper surface preparation is critical: the existing deck must be structurally sound, smooth, and free of debris. A cover board or slip sheet is typically installed between the insulation and the membrane to provide a clean substrate.
The membrane can be fully adhered, mechanically attached, or ballasted with stone. For residential sunroom and porch applications, fully adhered installation is most common. Adhesive is applied to the substrate, and the membrane is rolled into place, then rolled with a weighted roller to ensure full contact. All seams are cleaned with primer and spliced using EPDM seam tape or liquid splice adhesive. Flashing at penetrations, such as pipes, vents, and skylights, is done with uncured EPDM flashing that bonds to the cured field membrane. For more information on low-slope roofing options, see our flat roof systems guide.
Foundation Options for Decks, Additions, and Small Structures
When adding a deck, porch, or small addition, the foundation system you choose affects cost, construction speed, and long-term performance. Three popular options are traditional concrete footings, helical piles, and pin foundations.
Pin Foundations vs Helical Piles vs Concrete Footings
Each foundation type has specific advantages depending on soil conditions, frost depth, and load requirements.
- Pin foundations consist of steel pins that are driven into the ground with a hydraulic driver. They are fast to install, require minimal excavation, and are highly resistant to frost heave because the small shaft surface area reduces upward soil friction forces. They work best in well-drained, stable soils and for light to moderate loads such as decks and small porches.
- Helical piles are steel shafts with helical bearing plates that are screwed into the ground. They can support much heavier loads than pin foundations and can be installed in a wider range of soil conditions, including clay and loose fill. They are commonly used for building additions, manufactured homes, and boardwalks.
- Traditional concrete footings are the most familiar option. Poured concrete below the frost line provides a massive, stable bearing surface. They are suitable for any load condition but require excavation, formwork, concrete curing time, and careful backfilling. Frost heave resistance depends on the footing being poured below the frost line.
For most residential deck and porch projects, pin foundations offer the best balance of cost and performance in regions with well-drained soils. However, always consult a local structural engineer who understands the specific soil conditions on your site before making a final decision.
Whether you are adding a greedy dormer to gain living space, insulating a cathedral ceiling for comfort, replacing a flat roof with EPDM, or selecting foundation systems for a new structure, the common thread is careful planning and quality execution. Work with experienced contractors who understand building science principles, invest in proper flashing and detailing at every transition point, and never compromise on air-sealing and moisture management. These are the details that separate a durable, comfortable home from one that requires constant repair.