How To Make A Concrete Patio Bigger

Expanding an existing concrete patio offers increased outdoor living space. This process involves careful planning and execution to ensure the new concrete integrates seamlessly with the old. This article outlines the steps involved in expanding a concrete patio.

Planning and Preparation

Begin by assessing the current patio. Note its dimensions, condition, and surrounding landscape. Determine the desired size of the expansion and consider how it will impact existing drainage patterns and landscaping. Contact local utility companies to mark underground utilities before any digging commences.

Accurately measure the expansion area and create a detailed plan. This plan should include the dimensions of the new section and its relationship to the existing patio. This will be crucial for calculating material needs and ensuring a level surface.

Obtaining necessary permits is essential. Check with local building authorities for specific requirements and regulations regarding patio expansions. This ensures compliance with local codes and avoids potential issues down the line.

Materials and Tools

Assemble the required tools and materials. These will typically include: shovels, a wheelbarrow, a concrete mixer (or access to ready-mix concrete), stakes, string lines, a level, a screed board, a bull float, a hand float, a groover, a concrete saw (optional), rebar, concrete mix, gravel, and wood forms.

The amount of concrete needed can be calculated based on the dimensions of the expansion area and the desired thickness of the slab. It is advisable to order slightly more concrete than calculated to account for any spillage or variations in the subgrade.

Excavation and Formwork

Excavate the area for the expansion to the desired depth, typically around 4-6 inches. Ensure the base is level and compact. A compacted gravel base, approximately 4 inches thick, should be added and compacted again. This gravel base improves drainage and provides a stable foundation for the concrete.

Construct formwork using wood boards to define the perimeter of the new patio section. Secure the forms firmly in place with stakes to prevent movement during the concrete pour. The top edges of the forms should be level with the desired height of the finished patio.

Reinforcement and Concrete Pouring

Place rebar within the excavated area, supported by small stones or concrete blocks, to reinforce the concrete. The rebar should be spaced according to local building codes and should be placed within the center of the slab thickness. This reinforcement adds strength and helps prevent cracking.

Pour the concrete into the forms, starting at one corner and working across the area. Use a shovel or rake to spread the concrete evenly. Consolidate the concrete with a vibrator or by tamping it down to eliminate air pockets. Overfilling the forms slightly will allow for settling and screeding.

Finishing

Using a screed board, level the concrete surface by moving it back and forth across the forms. This creates a flat, even surface. After screeding, use a bull float to further smooth the surface and remove any imperfections.

Once the concrete has begun to set, use a hand float to create a smoother finish. This step also helps to embed any aggregate that may have risen to the surface. A groover can then be used to create control joints, which help prevent cracking due to temperature changes. These joints should be spaced at intervals roughly equal to two to three times the thickness of the slab.

Curing and Protection

Curing the concrete is crucial for its long-term strength and durability. Keep the concrete moist for several days after pouring. This can be achieved by covering the slab with plastic sheeting or by regularly misting it with water. Avoid heavy traffic on the new patio section for at least a week while the concrete cures.

Connecting Old and New Concrete

The connection between the existing patio and the new section is critical. Before pouring the new concrete, consider roughening the edge of the existing slab where the two will meet. This will create a better bond between the old and new concrete.

Expansion joints should be incorporated between the old and new slabs to allow for movement due to temperature changes. These joints can be filled with a flexible sealant to prevent water infiltration and debris buildup.

Landscaping and Final Touches

Once the concrete is fully cured, the surrounding landscape can be restored. This may involve backfilling around the edges of the new patio, replanting vegetation, or adding other landscaping features. Consider sealing the concrete to protect it from staining and weathering. This will also make it easier to clean and maintain.