How to Make a Concrete Mockup Board: Test Color and Finish Before You Pour

The mockup board is a controlled sandbox to test color, texture, and sealer before you commit to the full pour. Use it to spot color shifts and finish differences in a small, repeatable sample.

Set clear goals for color consistency, surface texture, and sealer compatibility. Pick a practical board size that’s easy to handle but large enough to reveal shifts and texture; outline a realistic timeline that covers planning, mixing, casting, curing, testing sealers, and evaluation, with a buffer for delays.

Define Test Objectives

The mockup board’s purpose is to test variables before the full pour. Decide which aspects you want to compare.

Colorant type: Consider different colors or stains to see how they look in concrete.

Finish: Test various textures like broom, trowel, or smooth finishes to find your preference.

Sealer compatibility: Check if water-based or solvent-based sealers work well with your chosen colorant or stain.

Select Size and Number of Samples

Choose a board size that’s small enough to be manageable but large enough to reveal color shifts and texture. Standard dimensions like 12″ x 18″ or 24″ x 24″ work well.

The number of samples depends on how many colors/finishes you want to compare. A good rule of thumb is one sample per variable, but you can adjust based on your needs.

For example, if you’re testing three colors and two finishes, make six samples. This way, you can see the impact of each variable clearly.

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Core materials include cement or concrete mix, fine aggregate, pigments or colorants, a release agent, sealer, and a backing board or mold. Each item matters for color accuracy and finish testing, so choose purposefully.

Gather essential tools: mixing container, paddle or drill, trowel, margin trowel, screed, floats, level, measuring cups, brushes or sponges, and PPE. Alternatives matter when budget or scale dictate different choices; pick options compatible with your sealer needs.

Choose rigid form materials like plywood or melamine with clean edges and consistent thickness. Decide on joint type and release strategy to prevent leaks and misalignment.

Assemble a square, leakproof frame with precise cuts and bracing. Plan minimal reinforcement if needed and position inserts to avoid air pockets while keeping demolding straightforward.

Choosing form materials and assembly tips

The right form materials ensure a leakproof, durable mockup board. Here’s what to consider:

• Plywood: Durable, strong, but heavy. Look for CDX or AC plywood with no voids or delamination. Apply a release agent and seal the edges.
• Melamine: Lightweight, smooth surface, but less durable. Use 1/2″ or 5/8″ thickness. Seal edges and apply a form-release coating.
• Foam: Inexpensive, lightweight, but not as strong. Choose closed-cell foam for moisture resistance. Seal edges and apply a release agent.
• Edge treatments: Use straight, clean edges to prevent leaks. Bevel or round edges for easier demolding.
• Sealing joints: Use a continuous perimeter gasket or tape to seal form joints. Ensure a perfect fit and no gaps.

Reinforcement and inserts

Adding reinforcement or inserts can strengthen your mockup board and test specific conditions:

When to add mesh or rebar: If your final pour requires it, include light reinforcement in your mockup. Avoid creating hard-to-reach air pockets.

Position embedded items carefully: Ensure they won’t affect test results or make demolding difficult. Use clips or screws to secure them in place during the pour.

Movement joints: If testing joint systems, position inserts accordingly. Avoid placing them where they could cause stress points or weaken the mockup.

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Clean the form thoroughly to remove dust, oil, and laitance using appropriate cleaners so color and finish aren’t muted. Allow surfaces to dry and inspect for residue before pouring.

Choose a sealing approach for the form surface and apply a release agent as needed. Time the release and sealing steps to protect the form and capture true finish results, then prep edges and joints for consistent results.

Cleaning and priming the form

Start by removing any dust, dirt, or debris from your form using a soft brush or compressed air. Oil and laitance can also mute colors, so use a mild detergent with water to clean these off.

For wooden forms: Apply a coat of form release wax or a mold-release-compatible sealer after cleaning. This prevents the concrete from sticking and ensures an even finish.

For metal forms: Use a rust-inhibiting primer followed by a thin coat of release agent. This protects the form and gives your mockup a smooth surface.

Release agents and masking details

Choose between dry powder, liquid, or wax release agents depending on your form material and desired finish. Apply according to the manufacturer’s instructions, usually before pouring.

Dry powder: Suitable for wooden forms, apply evenly with a brush. Shake off excess.

Liquid/wax: Ideal for metal or plastic forms, spray or wipe on thinly. Allow to dry slightly but not fully cure.

Mask any areas you want to leave exposed for comparative tests using painter’s tape and paper. This ensures those sections remain untouched by the release agent.

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Plan small batches that are representative of a full pour, focusing on achieving the target color and texture. Keep records so you can reproduce the mix later.

Evaluate pigment options and placement, whether integral or surface applied, and how each affects consistency. Document mixing order, batch size, and any adjustments for repeatability.

Mixing technique and consistency control

Start by dry blending your cement and aggregates. This ensures even distribution.

Add pigments next, mixing well to avoid clumps. Then slowly introduce water while continuing to mix. Follow product guidance for water-to-cement ratios; it’s usually around 0.45-0.65 by weight for mockups.

Control slump with admixtures if needed. Keep records of your measurements and adjustments to maintain consistency across batches.

Color methods: integral pigments, dyes, and stains

Integral pigments are best for mockups. They’re mixed into the concrete, providing consistent color throughout.

Surface dyes and stains can be used to mimic final finishes but may not provide accurate color representation in all conditions. Always check manufacturer dosing and application instructions.

For reactive stains, test on a small area first. They can darken over time, affecting your mockup’s realism.

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Follow a clear pour sequence and verify form preparation, release readiness, and reinforcement as needed. Keep pour height consistent to avoid cold joints in the mockup.

Consolidate the mix with controlled vibration and careful placement to minimize segregation. Use screeding and floats to achieve a true surface, then plan curing and finishing steps to match the final look.

Pouring and consolidation

Start pouring from one corner, working edge to center. This helps minimize segregation.

Consolidate the concrete as you go with a small vibrator or by tapping the forms. This releases trapped air without overworking the mix.

Aim for a consistent pour height to avoid cold joints in your mockup. Keep an eye on the slump; if it starts to drop, pause and remix.

Screeding, floating, and troweling timing

Begin screeding as soon as the concrete reaches the top of your forms. Work in passes, striking off high spots first, then leveling.

After screeding, use a bullfloat to close capillaries and remove laitance. Do this within 15-30 minutes after pouring, while the concrete is still plastic.

For a smooth finish, switch to a stiff float after bullfloating, then follow up with a flexible float for final smoothing. Trowel passes should start around 2 hours after pouring and continue every 15-30 minutes until desired sheen is achieved. Timing depends on ambient conditions and mix used.

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Use the mockup to evaluate how each surface treatment behaves before a full pour. Focus on look, feel, and behavior under planned conditions.

Briefly describe each finish option, including polish, acid stain, sealers, and color washes, and note expected visual outcomes. Document results with photos and notes for comparison.

Mechanical finishes (polish, exposed aggregate)

Test different polishing levels on your mockup to see how they change the look and feel of your concrete. Start with a light polish and work your way up to a high-gloss finish.

For each pass, record:

• Polishing level: Light, medium, or high gloss.
• Tool used: Diamond pads, polishing heads, etc.
• Number of passes: Keep track of how many times you’ve gone over the surface.

To expose aggregate, follow these steps:

1. Lightly polish the surface to remove any laitance (the weak top layer).

2. Use a diamond-impregnated grinding tool to expose the aggregate.

3. Record the type of aggregate used and the depth of exposure.

Chemical and topical finishes (stains, sealers, washes)

Test reactive stains, dyes, and different sealer types on your cured mockup to see how they change the color and sheen of your concrete.

For each application:

• Product name: Note the brand and specific product used.
• Color/Shade: Record the exact tone or shade applied.
• Application method: Brush, spray, roller, etc.
• Number of coats: Keep track of how many layers you’ve applied.

Evaluate color fastness and sheen by:

1. Comparing the mockup to your chosen color sample under different lighting conditions.

2. Checking for any discoloration or fading after exposure to sunlight, moisture, or other environmental factors.

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Set curing conditions that suit small panels and determine when they’re ready for finishing or sealing. Monitor moisture and hardness as you progress through testing.

Establish a simple documentation protocol with photos, notes on color match and moisture, and a clear decision workflow. Store results to guide future pours and color choices.

Curing methods and timelines

Proper curing is crucial for your concrete mockup to develop its full strength and desired finish. Here’s how to do it right.

Moist Curing: Keep the mockup damp by misting or covering with wet burlap or plastic. This helps maintain a consistent moisture level during the initial curing phase.

Plastic Covering: Wrap your mockup in plastic sheeting to retain moisture and heat, speeding up the curing process. Make sure it’s well-sealed at the edges.

Manufacturer Recommendations: Always check the specific concrete mix you’re using. Some mixes may require different curing times or methods. Don’t assume a one-size-fits-all approach.