Structural Floor Panels Design Guide - Hebel Supercrete AAC ...

1.2 Thermal Insulation
1.2.1 Inter-Storey Thermal Efficiency
Heat loss and gain through floors can contribute greatly
to the energy requirements of a building. Whilst only
about 10% of a room’s heat energy goes down through
a floor, approximately 42% of it goes up into the room
above. Having an efficient insulator between storeys greatly
improves the overall performance of a multi storey building,
especially the lower floors.
42%
48% 48%
10%
Approximate Distribution distribution of of heat heat transfer transfer through
the shell of through a typical the shell home. of a typical home
Note: Percentages can vary depending on insulation,
Note: Percentages can vary depending on insulation, area and
area and type of glazing etc.
type of glazing etc.
Supercrete Structural Floor Panels provide superior
levels of comfort, compared to conventional dense
concrete suspended slab floors. The cellular, aerated nature
of Supercrete Structural Floor Panels provides high
levels of thermal insulation, which is useful for containing
airborne convective heat in winter and blocking it out in
summer. Radiant heat is similarly contained. Under carpet
or tile heating mats benefit from being positioned on the
surface of Supercrete Structural Floor Panels, as these
panels greatly reduce heat loss into sub-floor spaces. Piped
underfloor heating systems can be bedded into a topping
screed (See Detail SFP 4-1, page 49).
Supercrete floors provide greater comfort
and thermal performance than traditional
concrete floors.
1.2.2 R-Value Calculation
Insulation is measured by the resistance to heat transfer
from one side of an object to the opposite side.
The resistance is known as an R-Value and uses the
measurements M2/KW. A floor made from 150mm dense concrete would have
an R-Value of around 0.10 compared with Supercrete
Structural Floor Panels of the same thickness having
an R-Value of 1.03, or approximately ten times better
insulation than dense concrete.
A typical thermal calculation for a floor/ceiling assembly is
shown below.
Table 1. R-Value Calculation
Top Surface Air Film = R 0.11
Carpet = R 0.17
Rubber Underlay = R 0.17
150mm Floor Panel (5% moisture) = R 0.85
Ceiling Cavity Airspace (non-reflective) = R 0.15
50mm Insulation = R 1.80
12mm Plasterboard Ceiling = R 0.05
Ceiling Surface Air Film (reflective) = R 0.23
TOTAL = R 3.53
Various floor assembly thermal and acoustic
performances are shown in Tables 2-8, pages 10-13.
1.3 Acoustic Performance
The field of acoustics is too broad to cover in depth in
these notes, however this section provides a brief overview
of the concepts of acoustic insulation.
Building noise can be broken into two basic categories,
Airborne noise and Impact noise. The following
sections detail how the Supercrete Structural Floor Panel
System deals with both types of noise.
What we hear as sound is actually small pressure
fluctuations in the air causing movement of the tiny bones
and membranes within our ear. Airborne noise is caused
by emitters of sound, such as stereos, TVs, human speech,
machinery, etc. These emitters of sound vibrate the air
around them and the radiating pressure ripples in the air
reach our ears, where we receive and identify the sound.
Impact noise is also heard because of air pressure
fluctuations, but this noise is caused by the direct impact or
force acting on an object, which causes vibration of both
the impacted item and the air around it, such as footsteps
on a floor surface, tapping on a wall, etc.
SFP 2012 8 Copyright © Supercrete Limited 2008