Roof
roof pitch
Drempel
Flat roof
Upper floor slab
Solid ceiling
timber-beamed ceiling
Nail binder
Attic conversion
External wall
Façade
Partition joint in a house
cellar wall
Ground floor
cellar ceiling
Stairway to the cellar
Solid ceiling
Cap ceiling
Timber joist floor/cavity
Special components
Uninsulated pipework means that some of the thermal energy it carries is lost without being utilised and ends up heating the cellar, which is usually undesirable. This is particularly the case in unheated or inadequately insulated areas such as cellars, attics or uninsulated outdoor areas.
The uninsulated pipes release heat into the surrounding environment, leading to increased energy consumption and higher heating costs. Furthermore, insufficient insulation of cold-water pipes can also lead to condensation problems, as these pipes are often colder than the ambient air, allowing moisture from the air to condense.
Incidentally, the insulation of heating pipes has been a legal requirement for more than 15 years. (First under the ENeV, then under the GEG)
Insulating pipework is an important measure for minimising energy losses and improving energy efficiency. There are various methods for insulating pipework:
Important: When fitting pipe insulation, care should be taken to ensure that air pockets between the insulation and the pipes, as well as excessive kinking of the insulation, do not lead to problems or reduced insulation performance.
- Pipe insulation sleeves: These prefabricated sleeves made of insulating material are simply placed around the pipework and secured. They are available in various sizes and insulation thicknesses and are easy to fit.
- Mineral wool: Mineral wool is available as loose mats or as pipe sleeves and is wrapped around the pipework or secured with fixing straps. It offers good thermal insulation and soundproofing properties.
- Polyethylene foam pipe insulation: A cost-effective option where the foam is simply slipped over the pipework. Here too, there is a choice of different insulation thicknesses and diameters.
- Armaflex pipe insulation: Armaflex is a flexible, closed-cell elastomeric foam material that offers good thermal insulation and soundproofing. It is available in various designs and thicknesses.
- Another way to insulate uninsulated heating pipes beneath the cellar ceiling is for the cellar ceiling insulation to enclose and wrap around the heating pipes. This is particularly straightforward if the suspended cellar ceiling is insulated with blow-in insulation. In this case, you’ve ‘killed two birds with one stone’.
Before insulating, it is important to clean the pipework thoroughly and check it for damage or leaks. The insulation should be fitted carefully and securely to achieve the best possible result.
Special considerations for rubber:
Proper installation of pipe insulation requires meticulous work. The joints between the insulation sleeves should be bonded evenly, and adhesive is also applied to the pipework. The adhesive is applied carefully with a brush and must be allowed to cure sufficiently. This insulation is effective at preventing condensation on cold-water pipes. When used on hot-water or low-temperature heating pipes, the thickness of the insulation layer must be taken into account.
There are also rubber variants available for heating pipes. Slotted shells make installation easier, and suitable fittings such as bends and T-joints are also available. Careful installation and high-quality insulation materials help to improve the energy efficiency of the pipework and prevent condensation.
Special features of rock wool:
Rock wool pipe sleeves are the right choice for temperatures up to 250°C. During installation, it is important to use a binding wire every 20–30 cm to ensure a secure hold and to seal the joints with aluminium tape. Careful, flush fitting minimises heat loss.
Elbows and T-pieces can be filled with insulation wool when PVC or sheet metal casings are used. Alternatively, prefabricated elbows and T-pieces are available.
Pipe clamps should be fitted with pipe sleeves or rubber hoses on both sides to ensure protection against water and maintain insulation efficiency.
Pipes/fittings with an internal diameter of up to 22 mm – the thickness of the insulation must be at least 20 mm.
Pipes/fittings with an internal diameter of more than 22 mm up to 35 mm – the insulation must be at least 30 mm thick.
Pipes/fittings with an internal diameter of more than 35 mm up to 100 mm – the insulation must be at least as thick as the internal diameter of the pipe
Pipes/fittings with an internal diameter of over 100 mm – the thickness of the insulation must be at least 100 mm.
Where pipes and fittings are located in wall and ceiling penetrations, at pipe junctions, at pipe connection points or near central distribution points, the minimum thickness of the insulation layer is half the values stated above.
For cold-water pipes, insulation thicknesses as low as 20 mm may be sufficient to prevent condensation problems and protect the pipes from freezing. The aluminium sheathing on the ‘warm side’ of the insulation must always be sealed airtight to prevent water vapour from entering the space between the insulation and the cold-water pipe and condensing there.
Insulation requirements for cold distribution pipes, ventilation ducts and air-conditioning
pipes For cold distribution and cold water pipes, as well as fittings for indoor air-handling and air-conditioning systems, the minimum thickness of the insulation layer is 6 millimetres.
Conversion of insulation thickness when using insulation materials with different thermal conductivities
For materials with thermal conductivities other than 0.035 watts per metre and kelvin, the minimum thicknesses of the insulation layers must be converted accordingly. The following formula applies to the conversion and the thermal conductivity of the insulation material:
New insulation thickness = New lambda divided by old lambda multiplied by old insulation thickness. Example:
0.040 / 0.035 × 20 mm = 22.8 mm
Exemptions from the insulation requirement for heating and hot-water
pipes Exemptions from the insulation requirement for pipework apply only to houses with no more than two flats, where the owner was already living in one of the flats before 1 February 2002. In such cases, the insulation requirement only comes into effect when the house is sold; the new owner must then retrofit the insulation within two years. However, as this insulation generally pays for itself after one heating season, owners should not delay in doing so.
All the benefits at a glance
Lower heating costs: Proper pipe insulation can reduce heating costs by up to 5 per cent.
Further benefits:
- Energy savings
- Environmental protection through reduced CO₂ emissions.
- Prevention of condensation problems and moisture damage.
- Extended service life of the pipework.
Financial support: This measure is required by law and is not eligible for financial support.
Can I insulate the pipes myself? Yes, pipe insulation is a simple insulation measure that, in many cases, can be carried out by DIY enthusiasts themselves. There are various types of ready-made pipe insulation, such as foam tubes or tubular insulation, which can simply be slipped over the pipes. These are available from DIY stores or online shops and can be fitted easily without any special tools.
Insulation materials: Armaflex, rock wool pipe sleeves with aluminium lining
