Gypsum Concrete Guide

Self-leveling with gypsum Concrete

For a long time, traditional concrete has been used to do solid work, but not until gypcrete was introduced a lightweight concrete that can as well do the concrete, ask I have mentioned before is light. It has some characters that we will be discussing in the article.

Key points:

  • Inspect joists for integrity.
  • Engage professionals for installation.
  • Pour and distribute mixture evenly.
  • Trowel for a level surface.
  • Allow 90 minutes before foot traffic.
  • Regulate moisture and temperature for drying.
  • Curing time varies.
  • Allow at least a week for drying before heavy loading.
  • Cover sound attenuation mats with plywood.

What is gypsum Concrete

Gypcrete, commonly known as gypsum concrete, is a composite material made of sand, Portland cement, and gypsum plaster. Gypcrete has several advantages, one of which is its small weight, which makes it very simple to deal with. It is a well-liked subflooring choice that works well with carpet and other adhesive-type floorings.

Self-leveling with gypsum concrete (gypcrete)

Prior to self-leveling with gypsum, inspecting the floor joists for weakness or damage is crucial to prevent cracks in the gypcrete. Installation of gypsum concrete necessitates professional expertise for meticulous mixing, pouring, and smooth application.

The prepared mixture is distributed evenly across the floor using a hose connected to a pump. A float trowel levels the top surface after pouring. Foot traffic is permissible 90 minutes post-completion.

Regulated moisture and temperature are essential for drying. Curing time varies based on thickness and material. Allow at least a week for drying before heavy loading. If a sound attenuation mat is present, covering it with plywood is recommended to avert cracking from excessive weight.

Where is gypsum concrete used?

Due to its fluidity, it is ideal for use in radiant floor heating systems. Gyp-Crete is put over the water pipes when they are initially installed. By placing furring strips in the middle, Gyp-Crete may also be used as an underlayment for hardwood floors.

Gypcrete characteristics

It can withstand up to 2,000 pounds per square inch of compression. The surface burning attributes of Gyp-Crete underlayment, such as fuel contribution, smoke density, and flame propagation, are zero.

Benefit of gypcrete

  • The speedy installation will also reduce inconvenience and delay, allowing you to utilize your property right away. Gypcrete installation takes just a few hours, not days or weeks. One day may be used to install 20,000 square feet of flooring, and 48 hours after installation, you can begin polishing the surface. 
  • When it comes to reducing noise, leveling floors, and using radiant heating, gypcrete has special merits.
  • Gypcrete has a number of advantages, but its greatest benefit is that it resists fire. 
  • Gypcrete’s modest weight allows for less strain on the building’s structure, enhancing stability and assurance.

Gypcrete concern

Gypcrete will eventually disintegrate and turn into a dust-like powder, necessitating costly replacement or re-pouring. Gyp-Crete installation on pre-existing structures is not advised for do-it-yourselfers. A licensed applicator is often needed for installation. Gyp-Crete floors save on building costs, but they can cost more over the course of their lifetime.

Can gypsum concrete be used as a finished floor?

Due to the nature of gypcrete and its purpose, gypsum concrete can not be used as a finished floor but can serve as an underlayment for a variety of other floor coverings as long as the overlay is not heavy.

Overlays (Toppings) over gypcrete 

Just like mentioned above, heavy toppings or overlays should be avoided because gypcrete is not as strong as concrete. There are only but a few overlays that can bond well with gypcrete. 

The best materials for this purpose may be certain engineered Hardwoods or primarily “floating” flooring like Laminate Flooring and Vinyl Plank. Gypcrete is always preferred over conventional solid wood “nail down” products. Gypcrete is inefficient as a basis for attaching wood floors using nails. 

Also, it is advised to seal the floor of the gypcrete so that you will be able to put carpet over the floor.

Floor types that can be overlaid for gypcrete

Vinyl Flooring (Seamless Full-Spread or Loose Lay)

Vinyl Flooring (Loose Lay w/ no Seams)

Laminate hard flooring


How to prep gypsum concrete before overlays

It is not actually necessary to seal vinyl flooring (minimal seams). However, sealing the gypsum will lessen the amount of dust that is released.

If you are installing seamless vinyl flooring, you must make sure the gypsum toppings are sealed to avoid problems with the glue and loose-lay seam tape. The extremely porous gypsum surface will cause the glue to dry up very rapidly, and the dusty surface will cause the loose lay-seam tape to loosen.

Laminate hardwood flooring: there is really no need for sealer or overspray. Gypsum will be sealed, which will lessen dust being stirred up,

Floating luxury vinyl flooring: When installing floating luxury vinyl flooring, I would ensure the gypsum toppings are sealed. Otherwise, dust from the gypsum topping would attach to the adhesive strips of these materials and weaken the necessary binding.

Before gluing anything on the gypcrete,  Doing a 24-hour bond test to check for the bond is highly advised when gluing down over gypsum tops.

Glue down the carpet: Gypsum toppings must be properly sealed in order to avoid adhesion problems during installation. Once more, this will cause the adhesive to dry out quickly and interfere with bonding.

Hardwood Glue Down: Gypsum Topping should be sealed. Depending on the hardwood product, you may either apply a resin-based glue or a urethane hardwood adhesive once the gypsum is sealed.

Glue Down Cork:  You will need to ensure that the gypsum topping is sealed. After the gypsum is sealed, you can use the recommended adhesive.

Problems of gypcrete

The major problem of gypcrete is moisture, Excess moisture in the substrate can cause adhesive failures, damage to the flooring, and mold issues. 

The less permeable the flooring the more impact excess moisture will have. Carpet and cushion with a permeable scrim slow moisture to pass from the substrate through the flooring system so the evaporation is continued.

Gypcrete cannot support a hard floor like a ceramic tile; if ceramic tile is put down immediately on top of fresh gypcrete, the substrate quickly begins to disintegrate. Within six months of installation, the ceramic tiles begin to shatter and make a very hollow sound. Gypcrete tends to break down into dust below the tile as a consequence of being compressed or damaged by a hard floor, such as ceramic, and this produces a hollow sound that will ultimately result in cracked tiles.

Gypcrete based self-leveler

  • Sika
  • SCHÖNOX AP Sythne
  • New Mapei
  • SL-Gyp™ 
michael Morris
michael Morris

Michael Morris is a seasoned professional with extensive experience and expertise in the field of self-leveling concrete, I am thrilled to share my knowledge with you.

Over the past five years, I have developed a deep understanding of the complexities involved in working with self-leveling concrete, and I'm here to provide practical advice and valuable insights for readers and enthusiasts alike.

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