Substrates or subfloors are the surfaces on which floor covering materials are applied. They can be made of wood, concrete, plywood, stone or metal. Regardless of the material, there are specific preparation considerations that must be met so as not to compromise the installation of the floor material. Of primary importance is the ability of the soil material to adhere to the surface on which it is applied. For the installation of stretch carpets, this is much easier, since the most important thing is that the substrate is level and any other factors affecting the carpet attached to the floor have practically no influence on an installation with pads and without studs.
First of all, the substrate must be clean and dry. It must be free of oil, grease, separation compounds, dust, dirt, grit, chemical contaminants, sealing and curing agents, paint, drywall compounds, old adhesives, such as loose or broken cutouts, solvents, and patching agents. The substrate should also not have cracks wide enough so that they can pass through the soil material. Wooden subfloors can cause moisture problems, especially particle board or OSB (fiberboard oriented). Wood is highly absorbent and can be dusty, so it would be necessary to apply a sealant to the surface.
This can be as simple as using latex milk or using a sealant manufactured by the manufacturer with any adhesive that is to be used or is mandatory (specified by the floor manufacturer). Wood also contains chemicals, binders, or resins, especially chipboard and OSB, but plywood and luan can do that too. Most adhesives contain water, which can cause a reaction with wood agents, causing the adhesive to dry and crystallize. This will result in the loss of the bond and ultimately a failure in the facility. You can also write on hardwood floors through vinyl floors just like chips on the OSB which can cause areas of discoloration on vinyl sheets.
Sometimes wood is treated with insect repellent which causes anything applied to it to lose its adhesion. In older historic buildings that were used for manufacturing you can count on oil having impregnated wooden floors which are ready to attack things that are left on top. In addition, the application of a cementitious agent on a wood substrate can cause the cementitious material to break due to the expansion contraction and bending of the wood substrate. In apartment buildings or smaller buildings where this condition is found the performance of the wooden subfloor must be taken into account. The correct new wooden subfloor must be used to make it compatible with the adhesive and the floor material to be installed.
Do not overlook the importance of the effects of the contribution or lack of contribution of wood substrates or the subfloor when installing a successful floor. CONCRETE AND HUMIDITY In the commercial environment concrete substrates are the norm whether new or old. One point to remember is that concrete must be considered a living material in a constant state of change. Concrete is never really dry and is always subject to a certain degree of hydration. It's also full of chemicals and minerals and if new can contain any number of adhesion-breaking additives which will prevent adhesives and flooring materials from adhering to it or coming off for a period of time. In addition to dust dirt or contaminants that may be in the concrete and that must be removed or contained with some type of sealant the natural aspects of the concrete must also be taken into account.
Concrete is a porous material through which water or other fluid materials can be easily transported along with the water-soluble materials of the concrete itself. As such pore water is made up of inorganic compounds and has a fairly high pH since concrete has a pH of 12.5 or more. Coatings on concrete surfaces designed to dry or seal it can also cause installation failure. Most concrete sealants affect pavement installations. Be wary of anyone who tells you otherwise they probably have a specific agenda to make you believe otherwise.
Contaminants such as oil grease oil-based sweeping compounds paint solvents and the like can cause adhesion failures and discoloration of vinyl flooring materials. Writing on concrete floors with anything but a pencil as with wooden subfloors can ensure that vinyl floors will stain in the future especially vinyl sheet materials which will reflect writing or marks on the substrate. All of this is chemistry and it's important to realize that reactions can occur between chemical agents that whether we like it or not will occur. If a pre-existing vinyl and asbestos tile with a reduced adhesive material based on black asphalt containing asbestos was installed and the floor was removed the chemical residues if not removed will cause the new floor installation to not work. If it is a vinyl material chemical waste can physically distort it.
Resolving this type of fault is extremely expensive. A new leveling agent or sealing agent cannot be placed if reducing chemicals remain as the chemicals will filter directly through them. BEST PRACTICES There are methods to help prevent failures whether you are installing hard or soft surface floor materials. You can polish concrete by shot blasting and seal it with several types of products or apply a new cement coating or a synthetic plaster product (which is different from ordinary white plaster). You can also apply a sealant that actually works.
Latex milk is likely sufficient for a hardwood floor but there are other types of wood sealants formulated specifically for that purpose. One of the most important things to remember is to ensure that the substrate is clean and dry and to use top quality adhesives and materials for soil preparation applied correctly in the right weather conditions it's often easier said than do it. You may feel that you are expected to be a chemical and a physicist to install floors properly but rest assured that following instructions should be enough to guarantee success when installing wooden flooring in historic or listed buildings.
