Roof insulation, so it is nice and warm in the upper room

While the facade insulation of the home belongs to professional hands, the correct roof insulation can be realized alone. Properly prepared and installed, conventional insulation materials can save up to 30 percent heat energy and the state even provides a subsidy.

Insulation as a holistic rehabilitation measure

The success of a roof insulation depends essentially on the fact that the optimal materials for the respective components for the energetic renovation are used. In addition, one must be aware that any action to Insulation holistic, so carried out for all areas of the property becomes. This means that it makes no sense to concentrate only on a single area, such as here in the roof insulation and elsewhere escapes heat energy, because the windows are leaking. And the heating must also be put to the test on the occasion.

Expertise in roof insulation

As a layman, and that is no shame, one can easily lose track of the abundance and variety of materials offered by the trade for building insulation. And then there is also the part that the legislator dictates, if for energetic redevelopment measures state subsidy centerl should bubble. The EnEV (Energy Saving Ordinance) regulates this very clearly and unequivocally that in this case, an energy consultant is needed, which should be involved in the planning during the work. Even the use of such a specialist is incidentally with subsidized up to 4.000, - Euro per investment project.

Roof insulation, so it is nice and warm in the upper room: insulation

The choice of insulation material decides

The roof insulation is basically the classic of energetic renovation, as it can be realized particularly easily and with little manual skill even by inexperienced homeowners. And here, the pitched roof should be mentioned in the first place, which is to be isolated in order to then use the space below as additional living space or just as a hobby room. The main requirements for insulating material used for it are the lowest possible weight and a degree of flexibility to clamp it as clean as possible and completely between the rafters. Priority is used for this purpose Mineral wool or a little better still, the glass wool.

Insulation materials for roof insulation and average costs

Here for a better overview a small, but by no means complete overview of the commercially available insulating materials for energetic roof renovation. The information on the minimum insulation thickness refers to one aspired insulation value of 0.24 W / (m²K)which the legislator prescribes with the EnEV provisions.

insulationThermal conductivity W / (m²K)Required material thickness (cm)Cost per m2 (Euro)
perlite0.04 to 0.072020 to 40
foam glass0.04 to 0.051640 to 60
glass wool0.032 to 0.0401410 to 20
rock wool0.035 to 0.0401410 to 20
Styrofoam0.035 to 0.045145 to 20
wood fiber0.04 to 0.0551840 to 50
excelsior0,0933680 to 90
cork0.04 to 0.051820 to 30
reed0.04 to 0.0551810 to 20

Possible insulation measures and average costs

The prices per square meter alone can be expected Cost of roof insulation but not yet calculated. The essential factor for this would be the chosen technology for this refurbishment, as can be seen more clearly in the following overview.

IsoliertechnologiePrice-performance ratioAverage cost per m2
rafterMediocre130 to 150 euros
Insulation between the raftersWell45 to 55 euros
Under raftersWell25 to 30 euros

Materials and tools for insulating the roof

List of materials:

  • Battens or squared lumber for additional doubling
  • Insulating material for rafter insulation
  • clamping felt
  • Underclamp and vapor barrier film
  • Adhesive and adhesive tape for sealing overlaps
  • Wooden slats and wood screws as well as ev. Nails

Tool overview:

  • Squares
  • tape measure
  • Suitable knife or saw for the insulation sheets for roof insulation
  • cutter
  • Electric stapler
  • Screwdriver or hammer
  • Handsaw for wood

Interim rafter roof insulation with insulation material in 7 steps

Professionals in the field of energetic building renovation like to talk about the fact that the insulation of a roof helps owners of the property between Save 25 and 30 percent of their energy consumption can. This requires, however, that all work to be carried out meticulously meticulous and carefully performed and the entire interior roof surface have been completely filled up with the exception of the last square millimeter and of course including the existing gable with insulating material.

Step 1: Measuring and ripping up rafters

That means nothing else than the first Intermediate spaces within the existing rafters reduced become. This is achieved by mounting additional battens with screws or nails on top of them, so that the insulation material later gets a firmer hold within the roof truss.

Step 2: Underlayer film for moisture control

On the rafters and as close as possible to the roof tiles, is now first a Moisture-insulating underlay film mounted, As a result, the insulating material will not be soaked from the outside (in the case of heavy rainfall), but it will still be able to release moist indoor air to the outside. At the bumps is the Foil finally sealed with tapeso that a completely isolated area results. A slight sagging of the film is thereby permitted and serves to ensure that the battens will not come into contact with expired condensation or rainwater later.

Step 3: Cutting the insulation material

If your hardware store does not offer the cutting of the insulation material from the roll to the dimensions of the required webs as a service, you have to do that yourself. It should be added on each side one to two centimeters, so that it can then be firmly clamped between the rafters and does not slip out by its own weight. The trade stops for extra thick insulation knife ready, if necessary and for smaller quantities it also does a sharp bread knife. In the processing of glass, mineral or rock wool is recommended Wear protective goggles, dust mask and gloves, because the small particles or fibers, which arise thereby, get as possible no body contact and certainly not to be inhaled.

Step 4: Insert the roof insulation

The precisely cut tracks are now clamped between each two rafters in the following step and should hold on their own. It is particularly important that the entire inside of the roof is completely covered with filling material and that no slits or gaps remain visible. These must otherwise necessarily with Residues from the blend to be repaired later heat losses or the Formation of condensation, which in turn can lead to mold growth, exclude.

Step 5: The vapor barrier film keeps the roof insulation dry

Some skill, or even better a helper, is needed to get the job done now Steam brake film evenly and firmly mount above the insulation strips. First, the individual tracks must be prepared so that they overlap laterally always ten centimeters before they are fixed without gaps in the wood using an electric bag. However, the film must not be under tension and should be much less damaged by cracks. Otherwise, it would have the mold later quite easily, possibly undetected for a long time, under the roof spread and Parts of the roof insulation to be affected.

Step 6: Seal all seams

Finally, all seams are hermetically sealed with a special adhesive tape, including any openings in your satellite system or extractor hoods. In addition, the film is in particularly stressed areas and for better adhesion with a sealed special sealing adhesive, As before with the underlayment film, the vapor barrier film must not be tensioned, as otherwise dangerous cracks may form shortly afterwards.

Step 7: A cross battens to the final

The Completion of your roof insulation forms the following transverse battens, which ensures that later a final ceiling covering, for example with gypsum fiber or plasterboard can be done if the attic is to be used for residential purposes. Before installing the wooden slats, the desired electrical cables or flush-mounted switch and socket outlets should ideally be installed immediately, as this room will later only be difficult to access. Otherwise, also profiled wood can be used very well, in order to make the entire roof surface visually and comfortably impressive.

Under- and rafter insulation explained briefly

Although both roof insulation technologies share the same goal in principle, they differ in the different approach to their structural design.

  • Under rafter insulation: Used in addition, if the Rafter or room height too low are to absorb the insulation material in the required material thickness - so the above-mentioned intermediate rafter insulation alone is not sufficient to realize the legal default values. Work steps and material usage are almost identical.
  • Aufsparrendämmung: Here is the Insulation material attached from the outsideif, for example, an upper floor has already been expanded and the intention is to re-cover the entire house roof. Due to the very complex design of this type of roof insulation, which would be practically equivalent to a new building, this professional technology, which is usually carried out by specialist companies, has only a very limited importance within the home improvement sector.

When sustainable roof insulation plays a role

Earlier it sounded already that certain insulation materials do not necessarily do any good for the human organism. On the other hand, it is highly gratifying that ecological and sustainable thinking is becoming more and more prevalent and, albeit tentative, being put into practice in our country too. Even if currently the mineral and synthetically produced insulating materials are in high demand, the Trend quite clearly to the vegetable products, If the legislature could decide to give renewable raw materials a higher priority in its stately promotional measures, their use in construction would already be many times wider, because it would be more attractive. Not only inveterate ecos have been tending for some time to greater use of flax, reed, coconut fiber and even sheep's wool on the construction. All these are optimal insulating materials for roof insulation of single and multi-family houses, with the quite reasonable goal:

Conserving raw material resources through cellulose fibers

The Recycled insulation paper can come from either old newspapers or leftover materials the printshops are produced cheaply. In the case of roof insulation, the fibers are shown in a simplified manner, simply blown into the cavities of the roof structure with a hose, which generally precludes thermal bridges and the associated energy losses. It produces neither a blend, as with conventional insulation material and the natural material cellulose also regulates the humidity in the rooms completely independently, Whether a property is ultimately suitable for the use of a roof insulation made of natural materials, an independent energy consultant can best estimate.

Tips & Tricks

When using the insulating mats, be sure to observe the applied marking. It must point into the room during installation and is divided transversely to the width so that it later remains firmly wedged between the rafters.

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