Through
the roof, we can escape even 30% of heat, and the cost of these losses can
reach, over a year, even over PLN 1000, for the entire roof. Therefore,
optimal and rational isolation of the roof slope, it is not only to obtain
thermal comfort and comfort of using the attic, but also measurable savings in
the cost of using our building.
Up
to 30% of heat can escape through the roof, and the cost of these losses can
reach up to more than PLN 1,000 for the entire roof per year. Therefore,
optimal and rational isolation of the roof slope is not only about achieving
thermal comfort and comfort of using the attic, but also measurable savings in
the cost of using our building.
Thermal
insulation, mineral wool, it
is usually laid between
rafters, when we want to get an attic.
The
heat transfer coefficient required by the construction law for the slope of
insulated slanted roofs should not be greater than 0.25 W / m2K, which means
that the optimal thickness of the thermal insulation material should be between 20
cm and 30
cm .
Due
to the fact that the standard rafter height is often 16 - 20
cm ,
and the recommended thickness of the insulation in the attic25-30 cm ,
the mineral wool insulation is made of two layers, the other (thickness of at
least 5
cm )
should also cover rafters.This allows for the elimination of thermal bridges in
these places. In
addition, it protects the wooden roof structure in the event of an attic fire.
Such
thickness provides good insulation of the attic from the roof heating up in the
summer (up to 60oC), and in winter reduces the energy used to heat the house
(through which the insulated roof escapes even 25 percent of heat). Mineral
wool also insulates the attic acoustically, especially against the sounds of
rain, which is particularly troublesome in the case of roofing with sheet
metal. It
is recommended to use glass wool in the form of Classic 035 mats in ECOSE®
Technology with a thermal conductivity coefficient of 0.035 W / mK
You
can also use other products from the Classic series in combination with mineral
stone polished TP 115 as a under-rafter insulation. Remember
that using insulation of the same thickness, and a better lambda (ie a smaller
value) we save more on heating.
The
mineral wool in ECOSE Technology by Kanuf Insulation is very convenient to
assemble: nice to touch, less dusty, odorless and easy to process. Moreover,
it is free of formaldehyde, phenol, acrylic and all coloring substances or
brighteners, which improves the quality of air in the attic.
Performance
tips
The
most common construction is an inclined roof with a wooden truss and a roofing
made of ceramic or cement tiles, mounted on patches and counter-battens. A
high-vapor permeable roof membrane is attached under the cover. Thanks
to such a membrane, wool insulation can fill the entire space between rafters
at their entire height. The
insulation is installed from the attic side over the entire rafter height,
without leaving a gap between the vapor-permeable membrane and thermal
insulation. First,
we unpack the wool, which will expand to the declared thickness. It's
good to shake the mat, just like a carpet, so that it will expand quickly. We
cut the mat in this way across a sharp knife to the previously measured length,
adding 20
mm of stock.
The
first layer of insulation
It
is recommended that the thickness of the first insulation layer be 0.5 to 1
cm smaller
than the height of the rafters, due to possible dimensional inaccuracy of the
rafter. The
membrane can not be pushed through the insulation and touch the roof covering.
Cut
the material, squeeze and lightly press it, place it between the rafters. After
laying and unfolding, the Classic 035 mat will be self-supporting without
additional protection. Wool
can not be frayed during cutting, and the cutting line should be different,
because only the exact filling of the space between the rafters will reduce the
risk of thermal bridges.
The
second layer of insulation
From the bottom of the
rafters we fix the auxiliary grate with wooden patches, the height of which
should enable the installation of an additional thermal insulation layer, or a
system metal grate, consisting of U-type distance rails and CD-type bearing
profiles or elastic profiles TN. Depending on the type of hangers, we attach
them to the forehead or sides of the rafters, at the spacing recommended by the
system manufacturer. If we use a metal grate for making this layer, it is
recommended to fill the profiles
with wool strips before assembly , which will favorably reduce the
energy loss. Due to the recommended total thickness of thermal insulation, the
second layer of insulation should have min. 5
cm . The material is also cut
laterally, taking into account15-20 mm stock. We install the second layer of
insulation, made of wool, between the grid slats.
Remember to use
insulating tape under the profiles to avoid transferring sounds. In places of inclination to the knee
wall and in the treatment of roof windows, it is best to use a Knauf elastic
profile. Convex basket supports
in the attic are secured with Alux protective tape. Profiles and hangers are screwed with
LN screws.
Vapor barrier
The next stage is the
location of the vapor barrier. It
is a film that limits the entry of steam from the bathroom, kitchen and living
rooms directly under the roof, where after condensation under the influence of
a lower temperature could lead to moisture in the mineral wool. The vapor barrier foil is glued to the
metal profiles by means of a special two-layer adhesive tape. The decision to install or not a vapor
barrier depends on the way of using the rooms in the attic and should always be
consulted with the designer. The
absolute requirement to mount a vapor barrier is in the case of wet or damp
rooms - bathrooms, kitchens or if we know that we will, for example, dry
clothes in these rooms. We
install the vapor barrier foil on the entire roof surface, arranging its belts
for a 10-centimeter plant.
The third layer of
insulation
If we decide to arrange
the third layer of insulation, we put it just between the vapor barrier and the
casing sheathing. We cut the wool
and assemble it as when making the second layer of insulation. Mat connections in this layer should
not overlap with connections in the previous layer. It is necessary to pay attention to
such a combination of roof insulation and insulation of the external wall in
the place of the eaves, so that there is no thermal bridge. The roof is subject to physical
forces, as a result of which its construction works. Therefore, it is not advisable to
attach the plasterboards directly to the roof truss. It is necessary to prepare the
construction of UD and CD metal profiles and direct hangers that will absorb
the work of the roof. We choose
such hangers, the length of which will enable the installation of insulation
with the assumed thickness. Remember
to use the insulating tape under the profiles to avoid transferring sounds. The final stage of works is the
assembly of plasterboard claddings.
Drywall cladding
Finally, we make the
cladding by screwing the plates to the CD profiles in a metal structure. Due to the usually wooden, and
therefore flammable roof truss, it
is advisable to use the red Knauf panel, which has fire-retardant properties, thanks to
the reinforcement of the fiberglass core.
Filling the laid boards
is carried out at a minimum ambient temperature of + 10 ° C, providing
increased ventilation of the rooms.We fill the joints with Uniflott, always
using reinforcing tape made of fiberglass or paper tape. After grouting the joints, you can
arrange wallpaper or paint the plates. An
interesting effect, reminiscent of plaster, gives a filling of the entire
surface of the boards. In this
case, it is best to use an Uniglatt gypsum plaster.
Knauf Insulation for
insulation of pitched roofs in the
rafters level recommends mineral wool products in ECOSE Technology:
· Classic 035 mats with
thermal conductivity λ = 0.035
There are also products
that can be used:
· Classic 039 mats with
thermal conductivity λ = 0.039
And plates
· TP 115 boards with thermal
conductivity λ = 0.037
· TP 112 boards with a thermal
conductivity λ = 0.039
We should remember that
products with better lower heat conduction coefficients l give us more energy
savings and thus smaller heating bills.
