How To Repair Shiplap Roofing

How To Repair Shiplap Roofing
  • Author: Amanda Arnold
  • Posted On: January 12, 2022
  • Updated On: August 21, 2023

You’ve decided to replace your roof. Following a few estimates, several roofing companies suggest tearing up your old roofing material and replacing it with plywood. If you’re wondering why your roofers can’t simply install new shingles and roofing accessories on top of your old roof deck, one of the most prevalent reasons is that your roof deck is shiplap.

When plywood hadn’t yet found its way into a new building in the 1950s and 1980s, shiplap roof decking was extensively employed. Shiplap resides beneath the roofs of many homes over thirty years old, having been designed specifically for asphalt shingles in the early days of its manufacture.

Shiplap is currently seen as a competitor to asphalt shingles. Most shingle manufacturers won’t warranty a roof that sits directly on a shiplap.

Shiplap Roof Decking: An Overview

Shiplap is found beneath the roof of many homes that are roughly thirty years old, and it was made perfect for asphalt shingles in its early days of manufacture. Asphalt shingles are now thought to hate shiplap. In actuality, a roof that is resting directly on a shiplap won’t be covered by most shingle manufacturers’ warranties.

Shiplap Roof Decking

The difficulty of immediately placing shingles over this subpar roof decking is largely due to the shifting and moving of the shiplap. Every piece of shiplap stretches and contracts in the winter and summer. The roofing nails or staples may eventually back themselves out of the roof deck as a result of this over time.

Why Do You Need To Repair Or Replace The Shiplap Roofing?

One of the main reasons it’s difficult to place shingles directly over this subpar roof decking is that shiplap moves and shifts.

All shiplap expands and contracts during the winter and summer seasons, some more than others, and as a result, the shingles tend to move when they are not supposed to move. This, in turn, can cause roofing nails or staples to back out of the roof deck over time.

We’ve seen roofing nails explode right through the surface of asphalt shingles in some cases, and entire roof decks in others, creating a slew of leaks and other water-related damage. Shiplap fir wood resin disappears over time, causing the boards to shrink, split, develop knot holes, and become highly brittle.

Between the once-tightly-fitted shiplap planks, open spaces appear. If the roofing underlayment is laid directly on the shiplap, it will droop and leak over time.

A Few Considerations Before Repairing The Shiplap Roofing

The shiplap on your roof indicates that the roof deck is at least 50 years old. It has dried up tremendously at this stage. Because the wood is brittle, there may be gaps between the boards where water can leak.

These planks are prone to cracks and knot holes, leading to leaks. If other shingles were put on the original roof, a new underlayer might be used to hide the shiplap, which can deteriorate over time.

Each layer creates new nail holes in the layers underneath it. Leaking can occur in any hole, fracture, or void.

Furthermore, when a new roof is built over the old shiplap, the nails that keep the roof in place do not go through the shiplap. This means that new shingles will not be fastened to the roof and are vulnerable to damage and leakage.

Steps To Repair The Shiplap Roofing

Electro-galvanized roofing nails enter the shiplap while installing new asphalt composition shingles, cracking or splitting the boards and impeding a suitable seal.


These nails push upwards through the newly installed tiles as they expand and contract. Raised nail heads can lead to seepage of migrating water and mysterious leaks. Wind gusts can blow the shingles off your roof if they aren’t properly attached.

Collect Needed Tools And Supplies

  • Solid shiplap roof Sheathing
  • Shiplap underlayer
  • Shingles
  • Screws
  • Power drill
  • Nails
  • A nail gun
  • Vapor barrier
  • Exterior-grade plywood

Go For The Solid Sheathing

Why take the chance of installing a roof with a 50-year warranty only to have it leak in a few years?


It’s to your best advantage to lay strong sheathing over the existing shiplap for your roofing system to fasten firmly if you don’t want to go through the hassle of tearing up your new roof and hunting for a mysterious leak. Exterior grade OSB boards and CDX genuine plywood are recommended.

Apply An Underlayer Over The Shiplap

Another popular approach is to install an underlayer over the shiplap, which is prone to deterioration as it ages. This is almost guaranteed if additional shingle layers were put over the original roof. Roofs with many layers of shingles are frequent on older roofs.

Apply An Underlayer Over The Shiplap

Each layer leaves a trail of nail holes in the layers beneath it. Each new hole, crack, or void increases the roof’s chances of leaking.

Another concern with building a new roof over a shiplap is that the nails fastening the new roof aren’t sunk into the shiplap, leaving the new shingle unsecured to the roof. This allows wind and rain to damage the new shingle and cause it to leak.

Install New Substrate

Removing the entire roof and starting over with a new substrate, vapor barrier, and shingles is one option to tackle these issues. Shiplap removal is time-consuming and costly. Resheeting directly over the shiplap with exterior-grade plywood is the most efficient and cost-effective alternative.

 Install New Substrate

This is approved by both the code and the roofing manufacturers. Your new composite shingle will be securely fitted to the new solid surface and will not leak for years. Your home is your most valuable asset. And when you need a new roof, it must be properly fitted.

Consider The Professional Roof Repairing Services

You should avoid roofing contractors that cut corners, and if you come across one who thinks it’s permissible to build a composition roof on top of a shiplap, politely decline. In the future, your roof, as well as your peace of mind, will reward you.

Professional Roof Repairing Services

If your property has shiplap, the best thing you can do when reroofing is demand that your roofing contractor installs new plywood sheathing/decking to avoid a costly and time-consuming repair later. Under today’s roofing industry standards, this is the most reliable and proven technique for reroofing your home.

Frequently Asked Questions

How To Repair Roof Decking?

Well, it is not budget-friendly and an ideal consideration to repair a roof decking. That’s why replacing old or damaged roof decking would be best rather than repairing it. You can do it yourself or hire professional deck installers to replace roof decking.

What Is The Cost Of Roof Deck Repairing?

The cost of roof deck repair or replacement depends on the condition of your roof deck. If you hire professionals for this project, it will cost you almost $300-$1000.


When your home needs a new roof, repairs, or upkeep, you’ll need a trusted roof repair firm. Your roofing contractor is responsible for keeping your home secure and dry. Hopefully, this article will guide you to repair the shiplap roof effortlessly and efficiently.

However, it would be best to hire professionals to repair the shiplap roofing appropriately.

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Author: Amanda Arnold

Amanda has been working with ConstructionHow since 2021. Her experience spans over 5 years in the creative niche such as home decor and trends, landscaping, renovations, and custom architectural values. As a home designer expert, she has a keen eye for the latest home improvement trends with accurate facts that readers find impossible to ignore. Being invested in home-building trends is how she has gained her lucrative expertise exploring more to bring a positive ambiance for all homeowners (and even tenants!). Currently, she lives in a beautiful beach home, a source of fascination for her.