Can concrete be poured over concrete?

Asked By: Mattie Kark | Last Updated: 12th May, 2020
Category: business and finance construction industry
5/5 (289 Views . 9 Votes)
Yes, you may pour a concrete pad overlay over an existing slab. You need to consider the added height and weight of the overlay on the existing structure. Overlays may include polymers, portland cement concrete, or epoxies. You should improve the drainage of the slab by having a good slope on the overlay.

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Besides, can new concrete be poured over old concrete?

If the existing concrete is in good shape structurally, you can pour new concrete over it to freshen it up. Proper prep work is key to success when layering new concrete over old. If the existing concrete is in good shape structurally, you can pour new concrete over it to freshen it up.

Also Know, how thick does a concrete overlay have to be? The minimum recommended thickness is 1 to 2 in. (25 to 50 mm) for a fully bonded concrete overlay placed on a base slab that is practically free of cracks and in which the concrete is sound, clean, and of good quality.

Hereof, how do you pour concrete on top of concrete?

To lay new concrete, sweep and clean the old concrete, and saturate the old concrete with water. Then, build a perimeter, or a wood brace, that is the same height as you want the concrete to be. Make sure the braces are level, and lay down a barrier of wire mesh over the existing concrete inside of the barrier.

Can you pour concrete over dirt?

Pour concrete over a solid, well-drained base Because concrete slabs “float” on the soil, soft ground or voids underneath may cause unsupported areas to crack under heavy weight like vehicles. Pack about 4 in. of sand or gravel over clay and other poorly draining soils to provide even support.

29 Related Question Answers Found

Does stamped concrete crack?

Stamped concrete is highly resistant to cracking when installed correctly. Even if stamped concrete experiences minor cracking, the cracks are often hard to detect because they will often blend in with the pattern and joint lines.

Does concrete resurfacing last?

Thanks to its advanced bonding properties, concrete resurfacing can last for quite a while. A properly resurfaced floor can last from 8-15 years.

What is concrete bonding adhesive?

QUIKRETE® Concrete Bonding Adhesive is specifically formulated for permanently bonding new concrete or plaster to old concrete or plaster. It is suitable for interior or exterior applications. QUIKRETE® Concrete Bonding Adhesive is also used as the required primer for QUIKRETE® Self- Leveling Floor Resurfacer.

What is concrete resurfacing?

Concrete resurfacing is a process by which concrete is cleaned, repaired, and overlaid with a new surface. Here is an overview of the steps involved for this fix to aging concrete: Cleaning.

When can I remove concrete forms?


Removing forms before the concrete is truly dry.
The forms or “molding” that holds the concrete in place until it dries should be left alone for at least two days to ensure that the concrete is completely dry.

How do you level existing concrete?

Here's what to do:
  1. Fill any cracks with epoxy.
  2. Apply latex bonding compound over all the concrete when the floor is absolutely dry.
  3. Mix the self-leveling compound with water, according to the manufacturer's instructions.
  4. Pour the self-leveling compound immediately, because it can dry very quickly.

How thin can concrete be poured?

There aren't many reasons to have only a 1-inch thick concrete surface. It is too thin to use as a flooring just by itself; however if you need to resurface damaged concrete, a 1-inch layer is a good amount. The old surface is prepared so that the new concrete will adhere, then the new cement is added.

How deep can you pour concrete?

Excavate the slab area to a depth of about 7 inches, allowing 3 inches for a gravel base and 4 inches for concrete.

How much is a cubic yard of concrete?

Cost. Use $90 per cubic yard as a ballpark figure for concrete prices, but concrete slab cost will vary by region. Also, expect a fee of about $60 per load for delivery from a concrete truck for concrete cost. There could be other fees for such things as Saturday concrete truck delivery and small loads.

Will concrete overlay crack?


But overlays are only as good as the subbase they are applied to. They are not intended to fix bad concrete. If you put an overlay directly over a cracked surface, the overlay is likely to crack as well.

Can you stamp over old concrete?

You can only stamp concrete when it is still wet from a pour. To add texture to an existing patio, pour a fresh layer of concrete over the old and stamp it, provided the existing patio is in good condition. You can impress the look of brick work over a new concrete surface.

Is concrete overlay expensive?

Concrete Resurfacing Costs. Concrete with a decorative overlay typically ranges in price from $7 to $12 per square foot while stamped concrete costs $8 to $20. Resurfacing breathes new life into a surface and costs less than installing a new slab.

Do you need rebar for 4 inch slab?

If you don't put rebars in a 4-inch [10 CM] slab, then it won't be reinforced concrete - and won't perform. As a general rule, any section of concrete must have at least 0.25% of its area in rebars to be considered reinforced concrete and do the intended job.

Can you pour your own concrete slab?

The bulk of the work for a new DIY concrete slab is in the excavation and form building. If you have to level a sloped site or bring in a lot of fill, hire an excavator for a day to help prepare the site. Then figure on spending a day building the forms and another pouring the slab.

Do you need gravel under concrete?


Whether you pour concrete for a walkway or patio, a strong gravel base is required to prevent the concrete from cracking and shifting. Gravel allows water to drain into the ground below. When packed tightly, however, the gravel doesn't shift beneath the concrete.

How do you prepare subgrade for concrete?

DIY Concrete: How to Prepare Your Subgrade
  1. Clear the area. Before you start any concrete project, you need to be sure you have a clear area.
  2. Backfill. Unless you are pouring on virgin clay, the area will need to be backfilled with either sand, gravel or crushed stone.
  3. Compact the subgrade. Compacting the subgrade is very important.
  4. Forming.

How do you smooth out concrete?

use steel finishing trowel for smooth texture
To finish the concrete, use a steel finishing trowel to achieve a smooth texture. The tool brings water to the surface of the concrete. Don't use too much water, but at the time same time, work the tool to create a smooth finish.