Installing Wooden Flooring in Historic or Listed Buildings: What You Need to Know

Installing wooden flooring in historic buildings requires special considerations such as moisture problems in wooden subfloors and chemical contaminants in concrete substrates.

Installing Wooden Flooring in Historic or Listed Buildings: What You Need to Know

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 that the installation of the floor material is not compromised. Of paramount importance is the ability of the floor material to adhere to the surface on which it is applied. For the elastic installation of carpets, this is much easier, since the most important thing is that the substrate is level, and any other factor affecting the carpet stuck to the floor has virtually no influence on a pad or an installation 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 hardening agents, paint, drywall compounds, old adhesives such as cutouts, solvents, and loose or broken patching agents. The substrate must also be free of cracks wide enough to telegraph through the soil material.


Wooden subfloors can have moisture problems, especially particle board or OSB (oriented fiberboard). 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 latex milk or a sealant made by the manufacturer of the adhesive to be used or required (specified by the floor manufacturer). Wood also contains chemicals, binders or resins, especially chipboard and OSB, but plywood and luan can also do this. 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 joint and, ultimately, a failure in the installation. Writing on wood floors can also pass through vinyl floors, as can bark chips on OSB, causing areas of discoloration on vinyl sheets.

The wood is treated with insect repellent from time to time, causing anything applied to it to lose its adhesion. In the oldest historic buildings that were once used for manufacturing, oil can be counted on to impregnate wooden floors, which are waiting to attack things stuck on top. In addition, the application of a cementitious agent to a wood substrate can cause the cementitious material to break due to the expansion, contraction and flexion of the wood substrate. In apartment buildings or smaller buildings where this condition is found, you have to consider what the wooden subfloor will do. The correct new wooden subfloor must be used to make it compatible with the adhesive and the floor material to be installed.

Don't overlook the importance of the effects of wood substrates or the contribution or lack of underlayment in a successful flooring installation.CONCRETE AND MOISTURE 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, constantly changing material. 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 amount of additives that break the bond and will prevent adhesives and flooring materials from sticking to it or causing it to peel off over a period of time. In addition to dust, dirt or contaminants that may be in the concrete and that need to be removed or contained with some type of sealant, there is also a need to deal with the natural aspects of concrete.

Concrete is a porous material through which water or other fluid materials can be easily transported, together with the water-soluble materials of the concrete itself. Therefore, interstitial water is made up of inorganic compounds and has a fairly high pH since concrete has a pH of 12.5 or higher. Coatings on concrete surfaces designed to dry or seal it can also cause installation failure. Most concrete sealants will affect flooring installations. Be wary of anyone who tells you otherwise; they probably have a specific agenda that makes 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 other than a pencil as with wooden subfloors can ensure that vinyl floors will stain in the future especially on vinyl sheets 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 was installed with a cut-out adhesive a black asphalt based material that contained asbestos and the floor was removed chemical waste if not removed will cause the new floor installation to fail. If it's a vinyl material chemical waste can physically distort it.

Resolving this type of failure is extraordinarily expensive. A new leveling agent or sealant cannot be placed if reducing chemicals remain as the chemicals will enter directly through them.BEST PRACTICES There are methods to help prevent failures whether you're installing hard- or soft-surface flooring materials. You can blast concrete and seal it with several types of products or apply a new cementitious coating or synthetic plaster product (which is different from regular white plaster). Or simply apply a sealant that actually works; latex milk is likely sufficient for a wooden floor but there are other types of wood sealants formulated specifically for that purpose. One of the most important things to remember is to make sure the substrate is clean and dry and using premium materials and adhesives for soil preparation which are applied correctly under the right weather conditions is often easier said than done. You may feel that you are expected to be chemical and physical to install the floor properly but rest assured that following instructions should be enough to get job done. You can expose small section your floor assess existence.