Metal vs Asphalt Roofing in Westfield: Technical Guide

Choosing between metal and asphalt for your Westfield home is a technical decision, not a style contest. Each system has specific deck requirements, underlayment pairings, fastener patterns, and ventilation math that must line up before the first square goes down. At Westfield Roofer, we walk homeowners through the exact specifications so the quote you sign matches the roof you actually get installed.

This guide is structured as a numbered walkthrough. You will see the sequence we follow during an inspection, the measurements we record, and the product tiers we pair with each system. The goal is to give you enough detail to ask sharper questions when any contractor (including us) hands you a proposal. If your roof does not need replacement, we will tell you. If it does, the steps below outline exactly how the work should be sequenced on a typical Central Indiana home with a 5/12 to 9/12 pitch and standard truss framing.

Numbers referenced here reflect common ranges for Westfield projects. Your actual scope depends on deck condition, pitch, penetrations, and code updates in your township.

Step-by-Step: How We Spec Metal vs Asphalt

1. Measure the roof and confirm pitch. We field-measure in squares (1 square = 100 sq ft). A typical Westfield ranch runs 18 to 28 squares. Pitch is recorded as rise over 12. Asphalt shingles require a minimum 2/12 pitch, with special underlayment below 4/12. Standing seam metal can go as low as 1/12 with sealed seams.
2. Inspect the decking. We pull 3 to 5 shingles in different zones and check sheathing thickness (7/16 OSB or 1/2 inch plywood is standard). Soft spots, delamination, and nail pops are flagged. Budget 1 to 3 sheets of replacement on most tear-offs.
3. Document ventilation. Code requires 1 sq ft of net free vent area per 150 sq ft of attic space, split 50/50 intake and exhaust. We count soffit vents and measure ridge vent linear feet. Undersized intake is the single most common defect we find on Westfield homes built before 2005.
4. Choose the system. Asphalt architectural shingles (Owens Corning Duration, Malarkey Vista) deliver a 25 to 30 year realistic service life at $4.50 to $7.50 per sq ft installed. Standing seam metal (24 gauge steel, 1.75 inch seam) delivers a 40 to 60 year service life at $11 to $16 per sq ft installed. Exposed-fastener metal (29 gauge) sits between at $7 to $10 per sq ft but requires gasket replacement at year 20.
5. Select underlayment. For asphalt, we specify synthetic underlayment (Titanium UDL30 or equivalent) across the field and self-adhered ice and water shield 24 inches past the interior wall line at eaves, plus all valleys and penetrations. For metal, we specify high-temp ice and water shield (240 F rating) across 100 percent of the deck to handle thermal cycling.
6. Plan the drip edge and starter. Drip edge is installed under underlayment at eaves and over underlayment at rakes, with a 2 inch overlap at splices. Asphalt systems use a factory starter strip with a sealant bead positioned 1 to 3 inches from the eave edge. Metal systems use a hemmed pan lock or cleat, fastened 12 inches on center.
7. Set the fastener schedule. Asphalt shingles require 6 nails per shingle in high-wind zones (anything rated above 110 mph), driven flush with 1.25 inch galvanized roofing nails into the nail line. Standing seam metal uses concealed clips every 16 to 24 inches with stainless or coated screws. Exposed-fastener metal uses #10 painted screws with EPDM washers at 24 inches on center at laps and 12 inches on center at eaves.
8. Detail the penetrations. Pipe boots should be lead or silicone (not neoprene, which fails at year 10 to 12 in Westfield UV exposure). Step flashing at walls is 4x5 inch pieces, one per shingle course. On metal, we use custom bent pan flashing with butyl tape sealant, never caulk alone.
9. Install valleys correctly. Closed-cut valleys are standard on asphalt: one side runs through, the other is trimmed 2 inches off center with a dubbed corner. Open metal valleys (W-valley, 24 gauge) are standard under metal panels and optional under premium asphalt, with hemmed edges and concealed clips.
10. Set ridge and hip details. Asphalt uses hip and ridge cap shingles nailed 1 inch back from the exposure line. Ridge vent is cut 3/4 inch back from the ridge board on each side, covered with baffled vent (Owens Corning VentSure or equivalent). Metal ridges use a vented closure strip with foam profile inserts matched to the panel.
11. Verify expansion allowances on metal. Panels longer than 30 feet need slotted clip holes or floating fastener points to allow 1/16 inch per 10 feet of thermal movement. Skipping this causes oil-canning and fastener back-out.
12. Document the install. We photograph every deck repair, underlayment layout, flashing detail, and fastener pattern. The packet goes to you with the manufacturer warranty registration (50 year non-prorated on Owens Corning Platinum, 40 year on most metal paint systems like Kynar 500).

Quick Comparison: Key Specs Side by Side

1. Weight: Asphalt architectural = 240 to 280 lb per square. 24 gauge standing seam = 100 to 150 lb per square.
2. Hail rating: Class 4 impact shingles (Malarkey Vista AR) match most 26 gauge metal for impact resistance. 24 gauge metal exceeds Class 4.
3. Wind rating: Asphitec 130 mph standard, 150 mph with 6-nail pattern. Standing seam tests to 160 mph with proper clip spacing.
4. Insurance impact: Class 4 shingles and metal both qualify for impact-resistant discounts with most Westfield carriers, typically 10 to 25 percent off the roof portion of premium.

Getting an Honest Recommendation for Your Westfield Roof

There is no universal right answer between metal and asphalt, only the answer that fits your house, your timeline, and your budget. Westfield Roofer will walk your roof, show you photos of what we find, and give you a straight recommendation even if that recommendation is to wait another two seasons before spending a dollar. Schedule a free inspection when you are ready, and we will help you decide with real information rather than pressure.

Frequently Asked Questions

Which lasts longer on Westfield homes, metal or asphalt?

Standing seam metal typically lasts 40 to 70 years, while quality architectural asphalt installed by Westfield Roofer runs 25 to 30 years in Westfield weather. Both can outlive cheaper versions of either product by a wide margin.

Is metal roofing worth the extra cost in Westfield?

It depends on how long you plan to stay. If you are in your forever home or have a low-slope section that asphalt struggles with, metal often pays off. For homeowners selling within 10 years, upgraded asphalt usually delivers better return in most Westfield neighborhoods.

Will my insurance cover switching from asphalt to metal?

Insurance generally covers like-for-like replacement. If your asphalt roof is approved for claim, you can often upgrade to metal by paying the cost difference. Westfield Roofer helps Westfield homeowners understand exactly what their policy allows before any decisions are made.

Does metal roofing make a house in Westfield louder during storms?

Properly installed metal over a solid deck with underlayment sounds nearly identical to asphalt from inside the house. The tin-roof-in-the-rain stereotype comes from bare metal on open purlins, which is not how residential metal is installed.

How do I know if I need a full replacement or just a repair?

A thorough inspection is the only honest answer. Westfield Roofer inspects roofs across Westfield and will tell you straight if a repair is the right call. If your roof does not need replacement, we will say so in writing.