King Roof Care, a locally owned Seattle roofer serving Kirkland, Bothell, Everett, Issaquah and Redmond, WA, works with PVC and metal roofing systems and replaces worn flat roofs with a new single-ply membrane. Other flat roof materials, such as EPDM, TPO, modified bitumen and built-up roofing, are compared below. This page does not confirm whether King Roof Care installs those, so ask during your free assessment.
Flat Roof Materials at a Glance: What King Roof Care Lists
Flat roof materials fall into a few broad families: single-ply membranes (PVC, TPO and EPDM), asphalt-based systems (built-up roofing and modified bitumen), metal panels, liquid coatings and vegetated green roofs. Each family handles seams, foot traffic and standing water differently.
| Material | General description | What King Roof Care's site states |
|---|---|---|
| PVC membrane | Single-ply thermoplastic sheet with heat-welded seams | Listed among the roofing systems the company works with |
| TPO membrane | Single-ply thermoplastic sheet, usually light colored | Not named on the site; ask whether it is offered |
| EPDM membrane | Single-ply synthetic rubber sheet, often black | Not named as an installed system; ask |
| Modified bitumen | Asphalt-based rolled sheets with added polymers | Not named as an installed system; ask |
| Built-up roofing | Layers of asphalt and reinforcing felts, often topped with gravel | Not named on the site; ask |
| Metal | Panels such as standing seam on suitable low slopes | Listed among the roofing systems; metal roof repairs listed |
| Coatings and green roofs | Liquid-applied layers or planted assemblies over a membrane | Not named on the site; ask |
Single-Ply Membranes for Flat Roofs: PVC, TPO and EPDM
Single-ply membranes are large sheets of one material rolled across the roof deck, and King Roof Care names a new single-ply membrane system as its approach when a deteriorating flat roof is replaced. The three common types differ mainly in how they are made and how their seams are joined.
Asphalt-Based Flat Roofs: Built-Up Roofing and Modified Bitumen
Built-up roofing, often called BUR or tar and gravel, is a flat roof system made of alternating layers of asphalt and reinforcing felts. A gravel or mineral surface is often added on top to protect the layers from sunlight and foot traffic.
Metal Panels, Roof Coatings and Green Roofs on Low-Slope Roofs
Metal roofing can work on some low-slope roofs, and King Roof Care lists metal among the roofing systems it works with, along with metal roof repairs for corrosion, damaged panels and sealing. Whether metal suits a particular roof depends on its actual pitch and the panel system's requirements, so a truly dead-level roof may not qualify.
Choosing a Flat Roof Material: A Decision Checklist
Choosing a flat roof material is easier when you answer a few practical questions before you look at product names. The checklist below is general guidance for homeowners in Kirkland, Bothell, Everett, Issaquah and Redmond, WA, and the answers will point toward one family of materials over another.
- Does water stand on the roof after rain? Ponding points to drainage and slope questions that no membrane alone will solve.
- Will people walk on the roof for decks, HVAC service or skylight cleaning? Foot traffic favors tougher surfaces and walkway protection.
- Are there many penetrations, such as vents, skylights or equipment curbs? More penetrations mean more flashing details to inspect.
- Is there exposure to grease, oils or chemicals? That is a common reason to consider PVC.
- What is the actual slope? Metal panels need enough pitch for the chosen system.
- How much weight can the framing carry? Built-up roofs and green roofs are heavier than single-ply sheets.
- Is the deck sound? Soft or damaged decking has to be repaired before any new material goes on.
- Is the existing roof layered over an older one? Hidden layers can trap moisture and affect the new installation.
What to Compare in a Flat Roof Replacement Estimate
A flat roof replacement estimate should name the exact material and scope, and King Roof Care states that it provides "a written estimate with the exact scope and materials before any work starts." King Roof Care also offers free, no-obligation roof assessments. Use the list below to compare written quotes line by line instead of by total price alone.
For budgeting, homewyse.com publishes a national planning range: "In September 2026 the estimated national average cost to Install a Membrane Roofing System starts at $8.23 - $10.54 per square foot." That is a national figure from homewyse, not a King Roof Care price. Your written estimate is the number that applies to your roof.
- Material name and product type, not just the word membrane.
- How seams will be joined: heat welding, adhesive or tape.
- Whether the old roofing is removed or covered over.
- How damaged decking or sheathing will be handled if found.
- Flashing at walls, skylights, vents and other penetrations.
- How drains, scuppers and edges will be addressed if water ponds today.
- Cleanup and debris removal.
How King Roof Care Handles Flat Roof Repairs and Replacement
King Roof Care's flat roof work covers both repair and replacement, and the company lists flat roof repairs for ponding water and membrane issues. A repair job typically begins with a thorough inspection to pinpoint the exact source of the problem. Leaks on a flat roof can travel before they show, so the guide on how to find a roof leak explains why the source is not always above the stain.
- Choosing a material before the cause of ponding water is understood.
- Covering wet insulation or soft decking instead of opening and repairing it.
- Treating a coating as a fix for a roof that is already failing.
- Overlooking flashing at skylights, walls and vents, where flat roof leaks often start.
- Comparing quotes that list different materials or scopes as if they were equal.
Frequently asked questions
What are the disadvantages of EPDM?
EPDM's main disadvantages are that its seams are usually joined with adhesives or tape rather than fused by heat, so seam and flashing workmanship matters a great deal. Black EPDM absorbs heat, and the rubber can be punctured by sharp debris or heavy foot traffic. King Roof Care's site does not name EPDM as an installed system, so ask during your assessment.
What time of year is the cheapest to replace a roof?
No seasonal pricing for roof replacement is published by King Roof Care, so the cheapest time of year cannot be stated here. The reliable way to compare cost is a written estimate: King Roof Care offers free, no-obligation roof assessments and a written estimate with the exact scope and materials before any work starts.
What style of home has a flat roof?
Flat roofs, which are actually low-slope roofs, are generally associated with modern and mid-century modern home designs. Flat roof sections also appear on many other homes as additions, porches, garages, dormers and decks over living space, even when the main roof is pitched.