Surface preparation is considered to be the most important step of any resinous flooring application. Improper surface preparation could turn what seems to be a simple process into a lengthy, difficult repair.
Concrete as a Substrate
Concrete is a substrate that is sometimes deceptively difficult to bond. There are four primary factors that contribute to the problems with concrete substrates:
- It is extremely alkaline, destroys the interface of hydrolysis sensitive materials.
- It has a weak, powdery surface layer, which must be penetrated or removed.
- It tends to crack for a considerable period of time after it has been formed.
- The main difficulty with bonding concrete is due to the presence of moisture. The moisture can be retained in fresh concrete and may be present in old concrete due to the environment.
Concrete provides a substrate surface that changes during its cure and also during environmental exposure. Concrete is a substrate whose surface characteristics are also likely to be affected by the environment in which it cures. The surface can be different depending on the temperature and humidity conditions during the cure of the concrete.
Once it is cured, concrete has several surface characteristics that are hazardous for bonding or sealing. The concrete surface is extremely alkaline and will destroy any hydrolysis sensitive materials that are present at the surface. Thus, sealers and primers are commonly used to moisture proof and strengthen the concrete surface prior to bonding.
All surfaces to receive düraamen™ sealers, coatings, underlays and overlays (toppings), must be structurally sound, clean and at minimum saturated surface dry (SSD). Proper surface preparation is extremely factor in the immediate and long-term successful performance of düraamen™ flooring systems.
Methods of Surface Preparation
Depending upon conditions of the concrete one or more methods of surface preparation may be required. It is common for decontamination to precede mechanical preparation, and if necessary a second decontamination to follow. The following table provides a guide for the degree of surface profile required for the coating or overlay to be applied and the preparation methods used to generate each profile.
APPLICATION | PROFILE | SURFACE PREPARATION METHOD |
Sealers | 0-3 mils | Detergent Scrub Low-pressure water Grinding |
Thin Film | 4-10 mils | Grinding Abrasive Blast Steel Shot Blast |
High-Build | 10-40 mils | Abrasive Blast Steel Shot Blast Scarifying |
Self-Leveling | 50mils – 1/8 inch | Abrasive Blast Steel Shot Blast Scarifying Needle Scaling High Pressure Water Jetting |
Polymer Overlay | 1/8-1/4 inch | Abrasive Blast Steel Shot Blast Scarifying Needle Scaling High Pressure Water Jetting Scabbling Flame Blasting |
After the substrate is prepared it must be inspected to insure that the substrate is sound and structurally durable. Areas found to be unsound or non-durable must be replaced as described below. Dust or other deleterious substance not removed after the initial surface preparation must be vacuumed, leaving the surface dust free and clean.
Removal and replacement of non-durable concrete must be accomplished prior to the installation of Duraamen™ flooring system. Localized weak or deteriorated concrete must be removed to sound concrete and replaced with cementitious polymer concrete or engineered concrete mix design.
You may download the technical bulletin for surface preparation below.