How to Spot Roof Deck Damage and Repair Roof Decking


A rooftop deck is a great space to include in a commercial or multifamily project. It gives tenants and residents an outdoor amenity where they can gather, enjoy the fresh air, and take in views of the city. But it is an additional space to maintain, and spotting roof deck rot early and immediately tackling repairs can prevent a larger, more costly repair down the road.

A roof deck can refer to two different things, so before we get going, let’s clarify both definitions. The first definition of roof deck is the bottom layer of structure of a roof that is typically plywood, OSB, concrete, or steel. The other definition of roof deck, or rooftop deck, is the rooftop space that acts as an amenity for tenants and residents that typically uses pavers as the final layer of roofing material.

Parts of a Roof

  • Roof deck - The roof deck refers to the entire roofing system that is attached to the roof beams. Typically made of plywood, OSB, concrete, or steel, the roof deck and its integrity is crucial to the roof’s performance and is what all of the other roofing materials are attached to.

  • Underlayment - The underlayment is the protective layer between the roof deck and the roofing material like shingles, sheet metal, or pavers.

  • Overburden - Any system or material that is installed above the underlayment membrane. Overburden systems include solar arrays, roof top decks, loose gravel, vegetative roof cover or green roofs, equipment, and water takes or stormwater retention systems.

  • Pavers - Pavers for a rooftop deck or plaza fall under the overburden category, but we’ll be discussing how to use them to help spot roof deck damage.

Signs of Roof Deck Rot

Roof deck rot refers to the rotting of the plywood or OSB boards that make the roof deck and that other roofing materials are attached to. Once the roof deck is rotted, the only repair is to replace the compromised materials.

Regularly inspecting the roof can help prevent damage from getting to the actual roof deck. Replacing broken or cracked roof shingles or tiles, repairing or replacing underlayment material, and keeping the roof surface free from debris, mold, and mildew can all help mitigate the risk of a rotten roof deck.

To check for signs of roof deck rot, you should conduct a visual inspection of the top layer of roof materials. Look for cracked or broken pavers, mold or mildew buildup, uneven surfaces, missing pavers, or large gaps between pavers.

You should also inspect the interior of the upper floor. Look for stains on the ceiling, areas that are sagging, leaks, and signs of mold or mildew. This should be done whether or not you’ve spotted signs on the roof’s surface. Sometimes roof rot occurs without visible signs on the roof’s surface, but signs of roof rot can be seen on the interior of the building. If there are exterior signs of roof rot, inspecting the interior can help you assess how extensive the damage is.

Other things to look for include:

  • A damp or musty smell

  • Discolored wood

  • Areas that feel unstable or “spongy” when walked on

  • Damaged or discolored insulation

If you spot any of these problems, it’s time to take a closer look and possibly repair the roof deck.

How to Repair a Roof Deck

  1. Determine how much of the roof deck will need to be replaced and purchase the necessary amount of materials — this includes plywood or OSB roof decking, underlayment, and replacement roof tiles, pavers, or shingles.

  2. Remove roofing material, such as pavers or shingles.

  3. Remove the underlayment.

  4. Assess the damage and mark the areas that need to be removed.

  5. Cut out the rotted wood and dispose of it properly.

  6. Assess any damage to the roof beams and replace or repair as necessary.

  7. Measure and cut the replacement decking.

  8. Put the decking in place and secure it to the roof beams.

  9. Replace the underlayment material.

  10. Replace the original roofing material if it can be reused or use new material.

Aspire Pavers Make Roof Deck Repair Easy

Aspire Pavers’ permeable system allows for water runoff which can mitigate the risk of damage that water poses to a roof. The installation grid and the pavers follow the slope of the roof and allow for water runoff, which lowers the risk of accumulating standing water under the pavers that can lead to roof rot and leaks.

If the roof deck does show signs of rot and needs to be replaced, the type of pavers that act as the roofing material have a large impact on how easy or difficult the repair process will be. If there are issues with the roof underlayment or the roof deck itself, being able to easily remove pavers to get to the problem areas is the key to keeping the project running smoothly.

Aspire Pavers use an installation grid that makes it easy to remove pavers, and the grid itself, to access the underlayment and roof deck. Grid installation systems can be removed and stacked for easy storage. The pavers that were removed can also be stored on the grids while the work on the roof deck is completed.

Other pavers, namely concrete and porcelain, use a pedestal paver system that makes roof deck repair more difficult. While the pavers lift off of the pedestals, their weight can require two people to lift them, and then the pedestals must be moved individually and stored elsewhere.

Aspire Pavers are lightweight and made with 95% post-consumer recycled materials. Their crack-resistant properties help to protect the roof deck from damage and their stain and scratch resistance will keep your rooftop deck or patio looking great for years to come.

Contact the experts at Aspire today to discuss finishing your roof with materials that will make future repairs easier than traditional materials.