A heating ground slab – everything you should know
Soils with both very good and poor bearing capacity allow to raise buildings on them using a ground slab. Such slab is chosen, among others, for houses with lower square footage (on good soil – where traditional Foundations would work), but most of all, for buildings with complicated floor plans – rested on poor soils. What is important, when going for a slab, not only do we get the Foundations but also the floor for the house’s lowest story. A well paved and smooth slab is all ready to have the flooring laid over it. No need to build the floor on the ground here – as is the case with regular Foundations. Utilizing this exact technology also allows to cut the house construction time by as much as a few weeks (as it will take less than a week to lay Foundations). A ground slab can also contain encased heating (a heating ground slab) – thus effectively using the concrete mass as a heat accumulating element.
What is a ground slab?
Construction of every residential building always has to start with creating its Foundations. One of the most popular options is placing strip footing on the soil, although an option growing in popularity these days is reinforced Concrete slabs (and heating ground slab), which prove to be a really convenient and noteworthy alternative.
A reinforced Concrete slab – which makes a type of foundation – is made under the entire building. Whereas traditional Foundations are usually laid slightly below the soil Freezing level, a foundation slab can be placed above the Freezing level.
With properly applied damp-proof membrane, a ground slab will also find use on damp soil. It is not difficult to apply damp-proof membrane to a slab, although it requires accuracy and also some experience.
Building a house on a foundation slab also allows to place effective thermal insulation on the ground (which in most cases is laid underneath the Foundations, to prevent thermal bridges from forming). Such insulation is not an option when it comes to strip footing and traditional foundation walls.
When planning to lay a ground slab, one has to keep in mind that it becomes necessary to map out all the connections, which means:
- gas system,
- piping and plumbing,
All of that has to be planned very carefully, because once the concrete is poured, it is not possible to change their position. However, a Concrete slab is still easier to build than other types of Foundations, and its creation consists of several simple stages. Once the concrete sets, we can start building walls right away.
A heating ground slab
One full-equipment option is installing a slab with an entire floor heating system. During the design stage, we need to decide on the type of heating. There are several types that are characterized by different materials, heat distribution and retention methods. There are different requirements to meet for a ground slab with water heating and for one with the electric type, or a hot-air one. The greatest downside of this type of solution is the high execution cost, without the ability to change it later or to build extra rooms.
In order to counteract the potential defects, it is the best to consider choosing a tested company that makes heating foundation slabs both during the design and implementation stage. The construction of a heating foundation slab doesn’t differ that much from making non-heating slabs.
The only difference is that specific elements have to be left in the concrete screed. The way it goes is that the following are covered with concrete inside the slab itself: galvanized steel pipes and a power generator with electric heaters (or a water heater – for Water-based heating). It is necessary to provide access to them later – through a floor hatch. A slab with heating channels prepared this way needs to be about 25-30 cm thick.
The purpose of steel pipes here is obviously to spread the heat around and heat the slab, which in turn will accumulate heat and slowly radiate it to the residential spaces. A huge advantage of such solution turns out to be the fact that one of the properties of concrete is heat accumulation.
A heated slab, therefore, starts working as a heat accumulator – providing as much thermal energy as is required to heat the interiors up to a specific air temperature.