Can You Lay Mortared Brick Over Treated Wood? Explained

The intersection of carpentry and masonry presents an intriguing proposition: can mortared brick structures be laid directly over treated wood surfaces? This question has garnered attention among craftsmen, builders, and homeowners seeking to merge the timeless beauty of brickwork with the versatility of wooden structures. While some argue that the inherent properties of treated wood discourage such integration, others explore the feasibility of this union by relying on careful planning, proper preparation, and specialized techniques. By delving into the intricacies of bricklaying, understanding the intricacies of treated wood, and exploring the concerns and considerations surrounding this practice, we can navigate the complex terrain where these two seemingly divergent materials converge, ultimately shedding light on the potential union that lies at the intersection of wooden substructures and mortared brickwork.

Does Mortar Rot Plywood?

However, not all types of wood are equally susceptible to rot when embedded in mortar. Plywood, in particular, is more resistant to rot than solid wood. This is due to the manufacturing process of plywood, where multiple layers of wood veneer are bonded together with glue and pressure. This construction method makes plywood less permeable to water and less prone to rotting.

Firstly, ensure that the plywood is adequately sealed or treated with a water-resistant coating before embedding it. This will create a protective barrier against moisture and reduce the chances of rot.

Another important factor is proper installation and maintenance. When embedding plywood in mortar, it’s crucial to ensure that it’s securely and tightly fitted to minimize gaps that could allow water infiltration. Regular inspections and prompt repair of any cracks or damage in the mortar will also help prevent moisture penetration and subsequent rot.

Types of Plywood That Are More Resistant to Rot

  • Marine plywood
  • Exterior plywood with a water-resistant adhesive
  • Pressure-treated plywood
  • Waterproof plywood
  • Composite plywood
  • Fire-resistant plywood
  • Moisture-resistant plywood
  • High-density overlay (HDO) plywood
  • Medium-density overlay (MDO) plywood

This is an important consideration when working with pressure treated wood and concrete. It’s crucial to ensure that the two materials can effectively bond together to create a stable and long-lasting structure. In this article, we will discuss how concrete and pressure treated wood can be used together, and the necessary steps to ensure a successful outcome.

Will Concrete Stick to Pressure Treated Wood?

The pressure treatment process of wood involves infusing chemicals that make it resistant to decay, rot, and insect damage. This treatment adds a protective layer to the wood, making it suitable for various outdoor applications. However, when it comes to concrete, there are concerns about whether it will stick to pressure treated wood or not.

The high alkaline nature of concrete actually helps to protect the wood by neutralizing any acids that may be present in the soil.

When constructing projects where pressure treated wood and concrete come into contact, such as deck posts or fence posts, it’s recommended to place the pressure treated wood directly against the concrete. This creates a strong bond between the two materials while also providing a barrier against moisture.

It’s important to note that any exterior concrete that’s in contact with the earth may wick moisture. To prevent moisture-related issues, it’s essential to use pressure treated wood in these situations.

This will create a moisture barrier and reduce the chances of moisture transfer from the concrete to the untreated wood, which could potentially lead to issues over time.

Source: Can pressure treated wood sit on concrete? – Quora

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Using mortar to adhere tiles to wood is indeed possible, but it’s crucial to choose the right type of mortar that’s suitable for wood surfaces. To ensure a secure bond, it’s recommended to use a flexible thin-set mortar mixed with a latex additive.

Can You Put Mortar Directly on Wood?

This type of mortar is designed to provide a strong bond to both the wood and the tiles, while still allowing for some flexibility, which is important for wood surfaces that can expand and contract with changes in temperature and humidity. Before applying the mortar, it’s important to prepare the wood surface properly. This typically involves cleaning the surface thoroughly and removing any existing finishes or coatings. The wood should also be sanded to create a rough surface that the mortar can adhere to. Once the surface is properly prepared, the mortar can be applied using a notched trowel. The tiles can then be pressed into place, and any excess mortar can be wiped away. It’s important to follow the manufacturers instructions for mixing and applying the mortar, as well as for allowing it to cure properly. Proper curing time is typically needed to ensure a strong bond between the mortar, wood, and tiles. Wood is a natural material that can shift and move over time, which can cause tiles and mortar to crack or come loose. In some cases, it may be more appropriate to use a different type of adhesive or fastening method when installing tiles on wood surfaces. It’s always a good idea to consult with a professional or do thorough research before undertaking a tiling project on a wood surface.

Potential Risks and Issues With Using Mortar on Wood Surfaces

  • Possible damage to the wood surface
  • Inability to properly adhere the mortar to the wood
  • <li Potential for cracking or crumbling of the mortar over time

  • Moisture damage and rotting of the wood beneath the mortar
  • <li Limited flexibility of the mortar, leading to structural issues

    <li Difficulty in removing the mortar if repairs or changes are needed

    <li Potential for insect infestation or mold growth in the mortar

    <li Aesthetically unappealing appearance of mortar on wood

    <li Decreased lifespan and durability of the wood surface

    <li Costly and time-consuming maintenance and reapplication of mortar over time

Once the painted wood surface has been properly prepped, you can proceed with applying a bonding agent or primer to improve the adhesion of the mortar. By following these steps, you can ensure that the mortar will adhere effectively to the wood and provide a strong and durable bond.

How Do You Get Mortar to Stick to Wood?

Once the wood surface is properly prepared, you can apply a bonding agent or primer specifically designed for use with mortar. Apply a thin, even coat of the bonding agent or primer to the prepared wood surface, following the manufacturers instructions.

If you’re using mortar to fill gaps or cracks in a wooden structure, consider using mortar repair caulk. This specialized caulk is designed to adhere to both wood and mortar, providing flexibility and durability. Apply the mortar repair caulk directly into the gap or crack, smoothing it out with a putty knife or your finger.

Once the mortar is applied, allow it to dry and cure according to the manufacturers instructions. This typically involves giving it ample time to harden and set, often ranging from a few hours to several days. During this curing process, it’s important to protect the mortar from moisture and excessive movement, as this can compromise the bond.

Following these steps will ensure a strong and long-lasting bond between the mortar and wood, allowing for various applications such as filling gaps or cracks, or even creating decorative designs on wooden surfaces.

Common Mistakes to Avoid When Using Mortar on Wood Surfaces

When applying mortar on wood surfaces, it’s important to avoid certain mistakes to ensure a proper and durable finish. Firstly, avoid using too much water when mixing the mortar as this can weaken it’s adhesive properties. Additionally, don’t apply the mortar directly onto bare wood as it may not bond properly. It’s best to use a bonding agent or apply a primer to the wood surface before applying the mortar. Another common mistake isn’t allowing the mortar to fully cure before subjecting it to heavy loads or moisture. This can lead to cracks and reduced durability. Lastly, make sure to follow the manufacturer’s instructions and recommended drying times for the mortar to achieve the best results.

When it comes to mortar and plywood adhesion, lower polymer content mortars are typically recommended. However, it’s essential to select a mortar that’s been specifically identified as having improved plywood adhesion. The ISO 13007 Standard provides valuable guidance in identifying such mortars, ensuring a strong and long-lasting bond between mortar and plywood.

Does Mortar Stick to Plywood?

When it comes to the question of whether mortar sticks to plywood, the answer lies in understanding the different types of mortar available and their compatibility with plywood surfaces.

Mortars with lower polymer content are generally recommended for plywood surfaces, as these tend to adhere better.

To ensure the compatibility of mortars with plywood, the ISO 13007 Standard serves as a valuable guideline. This standard helps users identify mortars that have been tested and proven to offer enhanced adhesion on plywood surfaces. By choosing a mortar that meets the requirements outlined in this standard, one can confidently ensure a strong bond between the mortar and plywood.

Without the use of an appropriate mortar, the risk of inadequate adhesion increases, which may result in the failure of the tile installation. This can lead to issues such as cracked tiles, water penetration, and instability.

This involves ensuring the plywood is clean, dry, and free from any contaminants that might hinder adhesion.

Mortar’s ability to adhere to plywood can vary depending on it’s composition. While some mortars are specifically designed to provide a strong bond with plywood, others may not adhere as effectively. To ensure a successful and long-lasting installation over plywood, it’s recommended to use mortars that have at least the P1 special characteristic.

Can Mortar Stick to Plywood?

When it comes to sticking mortar to plywood, the choice of mortar plays a crucial role. Certain mortars, such as the Kerabond/Keralastic™ System or Granirapid® System, possess the special characteristic of P2, which ensures optimal bond with plywood surfaces.

To achieve a successful installation over plywood, it’s advisable to opt for mortars that have at least the P1 special characteristic.

In addition to the special characteristics, it’s crucial to ensure proper surface preparation before applying mortar to plywood. The plywood surface should be clean, stable, and free from any contaminants that could hinder the bond between the mortar and substrate. It’s recommended to follow the manufacturers guidelines and instructions for surface preparation to achieve the best results.

This will result in a strong and durable installation that can withstand the challenges posed by plywoods natural movements.

Common Challenges and Considerations When Working With Mortar and Plywood

  • Choosing the right type of mortar for the project
  • Ensuring proper mixing ratios for mortar consistency
  • Creating a solid and level surface for plywood installation
  • Properly aligning and securing plywood sheets
  • Preventing moisture damage by using moisture barriers
  • Sealing plywood edges to minimize water penetration
  • Allowing sufficient drying time for mortar before applying weight
  • Avoiding excessive weight on plywood to prevent sagging or damage
  • Regularly inspecting and maintaining mortar and plywood for durability
  • Using proper safety precautions when working with mortar and plywood


In conclusion, the practice of laying mortared brick over treated wood isn’t recommended due to various concerns regarding long-term stability, durability, and safety. While it may seem like a convenient solution to incorporate the beauty of brick into wooden structures, it’s crucial to prioritize structural integrity and adherence to established building codes. The inherent differences in expansion, contraction, and moisture absorption between brick and wood pose significant challenges. Furthermore, the potential for moisture seepage, rot, and insect infestation in a mortar-to-wood interface raises further red flags. Sustainable alternatives, such as utilizing veneer brick or exploring other materials compatible with wooden structures, should be considered for the sake of maintaining structural soundness and ensuring the longevity of any construction project. It’s always advisable to consult professional architects, engineers, and contractors who possess the expertise to provide appropriate guidance and solutions.

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