A Choice of Heating Elements
Heating below a timber floor is acheiveable in different ways and Vysal has a solution for each!
You can use Vysa-Film radiant heating elements on either a concrete or timber sub-floor protected by Vysa-Pron insulation. This system is ideal in only minimally raising floor levels and can be used below laminate, engineered timber, parquet or bamboo flooring systems. However, Vysa-Film is not suitable for bathroom or wetroom use.
For any application including bathrooms and wetrooms, select Vysa-Foil mats which can also be used on either timber or concrete sub-floors with Vysa-Pron insulation in between. This method uses fluoropolymer heating cables encased in an aluminium foil.
You can also choose any of the Vysa-Mat Classic heating mat range or the Vysa-Cable products again for use on either timber or concrete sub-floors. In such circumstances, you should fit Vysa-Pron Max insulation between the heating element and the sub-floor. The installer will need to lay a self-levelling laytex floor compound covering the heating elements and the wooden floor (laminate, engineered timber, parquet or bamboo) can then be fitted once the compound has fully dried.
All three solutions will provide heat and comfort. If you need advice as to which will best suit YOUR requirements, give our advice line a quick call.
Humidity and dimensional changes
A well established, if perhaps not so well-known, phenomenon is that “A piece of wood is stable when its moisture content becomes equal to that of the surrounding environment when it neither gains nor loses humidity. Consequently, the balance of equilibrium varies on the basis of the temperature and level of ambient relative humidity.” As a result, the dimensions of wooden flooring boards are affected directly by changes in ambient humidity. The moisture content of wood will rise if the relative humidity (RH) is higher than usual, and conversely, the wood will lose some of its moisture content (MC) if the ambient air is too dry. These variations in the moisture content of the wood will cause the wooden flooring boards to expand or contract. Wood is dried to a moisture content (MC) of 6% to 9% before the flooring boards are shaped. Relative humidity (RH) during the pre-finishing phase averages 40%. The manufacturer’s warehouse is normally heated and ventilated so that finished products are stored in ideal conditions while awaiting shipment. Even when dried correctly, wood continues to react to changes in relative humidity.
|The table below shows how moisture content (MC) of wood varies with relative humidity (RH%) and temperature.|
|Temp||RH 25%||RH 30%||RH 35%||RH 40%||RH 45%||RH 50%||RH 55%||RH 60%||RH 65%||RH 70%||RH 75%|
Definition of normal moisture content (MC).
An ideal MC must be fixed to enable calculation of variations in dimension. However, a normal MC value is not an absolute value, because there are differences in the MC of boards that have been dried at the same time. Stable, good quality boards are characterized by a MC between 6% and 9%. There are different causes for variations, for example, in the size of the raw lumber, differing humidity rates in trees before they are cut and dried, etc.
For practical purposes, it is possible to use an average figure based on the data used to prepare the table above which shows how moisture content (MC) of wood varies with relative humidity (RH%) and temperature. Thus we find that typically wood is stable in a relative humidity environment varying between 35% and 40% and the MC ranges from 6.9% to 7.7%.