Cost to Replace Roof Decking and Underlayment in Katy
Replace roof decking in Katy for $2,600 to $9,000, plus underlayment. See what drives the price and how to estimate your project.
Last Updated: November 4, 2026
Quick Summary
To replace roof decking and underlayment, expect decking replacement to run about $2,600 to $9,000 nationally, depending on the sheathing material. Underlayment replacement averages around $3,300 nationally, with most homeowners spending between $1,700 and $4,200.
- Decking replacement typically runs $2,600 to $9,000, depending on sheathing material.
- Underlayment replacement averages about $3,300 nationally, with most spending $1,700 to $4,200.
- These are national benchmarks, not Katy-specific quotes, so get a local written estimate.
- Confirm whether each quote is material only, installed, or includes tear-off and disposal before comparing.
Table of Contents
- What Replacing Roof Decking and Underlayment Typically Costs
- Cost to Replace Roof Decking and Underlayment Per Square Foot
- Labor Cost to Replace Roof Decking: What Drives the Bill
- OSB Versus Plywood and Other Material Choices
- How to Calculate Roof Area and Estimate Your Project
- Replacing Roof Decking and Underlayment in Katy, Texas
- Scheduling Your Free Inspection and Getting a Written Estimate
- Frequently Asked Questions
What Replacing Roof Decking and Underlayment Typically Costs
Roof decking replacement typically runs between $2,600 and $9,000, depending on the sheathing material, according to Angi's 2026 roof decking replacement cost estimate. Underlayment replacement is a separate line item, and nationally it averages about $3,300, with most homeowners spending between $1,700 and $4,200 (Angi's 2026 roof underlayment replacement cost guide). Those figures are national benchmarks, not Katy quotes, so treat them as a starting point rather than a local price.
For a project-specific number, visit the Roof Repair Company website for current pricing or a quote tailored to your roof size and condition.
Cost to Replace Roof Decking and Underlayment Per Square Foot
Per-square-foot figures are where most of the confusion starts, because decking and underlayment are priced on different bases and the ranges you see online often describe different scopes. For a deeper, in-depth guide on the replacement process and pricing from the crews who do the work, see in-depth roof replacement guides. Compare quotes on equal terms by confirming what each price includes.
| Component | Unit | Typical national range | What the range usually covers |
|---|---|---|---|
| OSB sheathing, material only | Per 4x8 sheet (32 sq ft) | $15 to $30 | 7/16-inch to 15/32-inch OSB, no labor |
| Plywood sheathing, material only | Per 4x8 sheet (32 sq ft) | $25 to $55 | 15/32-inch to 19/32-inch CDX or better |
| Decking removal and replacement, labor | Per square (100 sq ft) | $150 to $400 | Tear-off of old panels, fastening, disposal |
| Felt underlayment, installed | Per square | $30 to $60 | #15 or #30 felt, lap and fasten |
| Synthetic underlayment, installed | Per square | $60 to $120 | Standard synthetic roll goods |
| Ice and water shield, installed | Per linear foot | $2 to $5 | Eaves, valleys, and penetrations only |
| Combined decking plus underlayment | Per square | $250 to $600 | New sheathing plus synthetic underlayment, labor included |
For underlayment alone, Homewyse's May 2026 installation cost estimate puts basic installation at $1.08 to $1.31 per square foot, while CountBricks estimates $3.00 to $5.00 per square foot for replacement work (CountBricks roofing underlayment cost guide). The gap is large because one figure covers installation under simple conditions and the other covers full replacement, including tear-off of the old underlayment and any prep work. Neither figure includes new decking.
To get a combined per-square-foot number, add the decking line to the underlayment line from your own quotes. Make sure both quotes cover the same scope before comparing totals.
Watch out: a low per-square-foot quote that excludes tear-off, disposal, or drip edge is not comparable to a quote that includes them. Ask each contractor to state whether the rate is material only, installed, or installed with tear-off and disposal.
Site conditions and material options can change the price significantly. A per-square-foot number tells you the unit rate, but your total depends on how much area needs work, how steep the roof is, and what has to be torn off first. Steep roofs, multi-story access, and roofs with many penetrations generally raise the rate.
Labor Cost to Replace Roof Decking: What Drives the Bill
Labor is often the largest part of a decking job, because the old roofing has to come off before new sheathing goes down. Tear-off, disposal, and the time needed to replace rotted boards all add hours to the crew's schedule. Access and roof pitch matter too. A steep or multi-story roof takes more time and more safety equipment than a low, simple one.
Damage severity is the biggest unknown. If you suspect ventilation problems contributed to the decking damage, ventilation repair guidance for Katy homeowners explains how to tell. Soft or sagging decking can hide rot that extends beyond the visible area, which is why a physical inspection before quoting matters. Once the crew opens the roof, they may find more compromised boards than expected, and that change should appear as a documented change order rather than a surprise invoice.
OSB Versus Plywood and Other Material Choices
Oriented strand board (OSB) and plywood are the two most common sheathing options. OSB is generally less expensive per sheet, while plywood tends to hold fasteners better and handles moisture exposure more gracefully. The right choice depends on your climate, your budget, and whether your existing deck was already plywood.
Underlayment choice affects cost too. Felt underlayment is the lowest-cost option. Synthetic underlayment costs more but resists tearing and moisture better. Ice and water shield is typically used along eaves, valleys, and penetrations rather than across the whole roof. Ask your contractor to specify the product and thickness in writing so you can compare quotes on equal terms.
How to Calculate Roof Area and Estimate Your Project
Start with your roof's footprint. Measure the length and width of each section, multiply to get the area, and add the pitch factor if your roof is steep. A common rule of thumb is that roofing is priced by the "square," which equals 100 square feet. Add a waste allowance of roughly 10 percent for cuts, overlaps, and trimmed sheets.
Once you have the area, multiply it by the per-square-foot rate you are comparing. Then add tear-off and disposal, which contractors often list as separate line items. Compare quotes using the same scope so the totals reflect the same work.
Replacing Roof Decking and Underlayment in Katy, Texas
Katy sits in the Houston metro, where heat, humidity, and periodic heavy rain put steady strain on roof decking and underlayment. Moisture that gets past aging underlayment can rot sheathing from below, and poor attic ventilation makes the problem worse. Those conditions shape both what you pay and what you should specify.
Roofing crew inspecting exposed plywood before they replace roof decking on a suburban home in Katy, Texas.
Local cost drivers. Most published decking and underlayment prices are national averages, and Local conditions such as labor availability, storm demand, roof complexity, and material delivery can affect the final price. Confirm the local figure with a current written quote.
A worked example. For a 2,000-square-foot roof (20 squares), the total is the number of squares multiplied by the combined per-square rate from your quotes. Add tear-off and disposal if not already included, plus ice and water shield at eaves and valleys.
Permits and code. Roofing permit requirements depend on the project and jurisdiction. Katy-area homeowners should verify with the city or county permitting office whether a decking replacement requires a permit, and ask the contractor to confirm that new sheathing and underlayment meet the current adopted building code and manufacturer installation instructions. Do not assume a permit is or is not required based on a neighbor's experience.
Insurance documentation. If the work follows storm or hail damage, keep a written inspection summary, photos of the damaged decking before it is covered, and the contractor's itemized estimate. Most insurers want to see the damage documented before repairs begin, and a written summary of findings is easier to submit than a verbal description.
For Katy-area help, visit Roof Repair Company's website to confirm service coverage in your area. Roof Repair Company offers free storm and hail damage inspections and a written summary of findings that you can use for insurance claims.
!A roofing crew in work clothes inspecting exposed plywood roof decking on a single-story suburban home in Katy, Texas under bright daylight
Scheduling Your Free Inspection and Getting a Written Estimate
The fastest way to a reliable number is a physical inspection. Ask questions about any line item in your written estimate that looks unclear.
Our free inspection is the next step. Schedule it to start the process.
Frequently Asked Questions
Is it expensive to replace roof decking?
Roof decking replacement cost depends on the sheathing material and how much of the roof needs new decking. Costs can rise when rot or water damage extends across large sections, because more panels must be removed and replaced. Getting a written estimate that separates decking, underlayment, and disposal lets you compare quotes accurately.
Will insurance pay for new roof decking?
Insurance may cover roof decking when the damage comes from a covered event such as a storm, hail, or a sudden leak. Coverage usually excludes damage from long-term neglect or wear. Document the damage with photos and a written inspection summary, and review your policy or ask your adjuster which portions of the repair are covered.
How much does roof underlayment replacement cost?
Underlayment replacement cost depends on roof size, pitch, and whether the existing underlayment must be torn off first. Use a written quote for your roof to get an accurate figure.
How much does it cost to replace roof decking and underlayment per square foot?
Underlayment and decking are priced separately, and per-square-foot rates vary by source and site conditions. Confirm the total with a site-specific quote.
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