What does ceiling insulation involve and which materials are the best for it?

What role is played by the insulation of a concrete and wooden ceiling?

In construction, the term ‘ceiling’ (or ‘floor’) refers to a horizontal partition within the structure of a building. The main role of that element is to transfer loads to the walls and columns that bear (carry) the weight. A ceiling delimits individual storeys, integrates the whole structure and acts as a thermal insulation partition that separates the lower storeys from the attic. Does it make sense to insulate a ceiling in the attic? Definitely yes! A man characteristic of heat is that is always moves up, so it can be stopped by, for example, the horizontal layers of ceiling insulation.

The insulation of a concrete or wooden ceiling brings the property owners a lot of benefits relating to both finance and health. Careful insulation of a concrete ceiling in an attic reduces the energy bills. It is also easier to maintain the humidity and temperature that’s appropriate for the room. How then to insulate a concrete ceiling from top and from the bottom? How to insulate an attic ceiling? Let’s check it out!

Insulating a ceiling with wool: pros and cons

What to use to insulate a ceiling? Many installers will reply without hesitation that wool will be the best for a ceiling, especially in energy-efficient buildings. This may be mineral wool (ceiling insulation wool) or glass wool. Why is it worth insulating a ceiling with mineral wool? It shows a low heat transfer coefficient, perfectly separates moisture, is inflammable, and ensures acoustic comfort inside the rooms. In addition, installing wool on a ceiling is not difficult; you can install it by yourself, without help from professionals. Wool proves to be good for beam and slab ceilings, as an insulation for a truss ceiling, solid slab ceiling, etc.

What should you know about the disadvantages of wool insulation? When we place wet mineral wool on a ceiling, we lose its thermal insulation parameters. The rock wool on the ceiling becomes heavy and gradually releases moisture outside, which can cause the formation of mould on walls and ceilings.

How to insulate a ceiling with mineral wool?

We already know which type of wool is the best as ceiling insulation. Let’s now talk about the installation process. How to place mineral wool on a ceiling and which thickness of the wool will be appropriate for a ceiling? The installation method and the number of layers obviously depend on the building characteristics and the design criteria.

Which wool to use for a wooden or concrete ceiling? For this purpose, it is best to use one or two layers of 15 cm mineral wool. The thickness of wool for a non-usable attic should be adjusted to the current standards of thermal performance. Non-heated, cold spaces in the attic should be separated with a thicker layer of wool (25–30 cm).

How to install mineral wool on a concrete or wooden ceiling? Such structures are usually covered with insulating foils or sleepers: one or two layers of wool should be placed between the beams. The last element is the floor made of wooden boards or wood-based panels. Mineral wool can be attached to the ceiling from the bottom with appropriate mounting adhesives.

Insulating a concrete ceiling with Styrofoam

A good many investors decide to insulate a concrete ceiling with Styrofoam. That material is very light and easy to process, while ensuring excellent protection against the loss of heat and the formation of thermal bridges. How to insulate a concrete ceiling with Styrofoam boards? Arrange extruded polystyrene on the insulating foils alternately; do not allow any gaps between the layers of material. Then insulate the extruded polystyrene with plastic sheeting and make a screed floor.

You can also use Styrofoam to insulate a concrete ceiling from the inside and from the outside, including to make insulation for a roof slab. Extruded polystyrene boards also make for effective insulation of a ceiling under a non-heated attic.

How to insulate a concrete ceiling in a non-usable attic? PIR boards

Polyurethane foam boards, such as EUROPIR®, are increasing in popularity on the market for  thermal insulation materials. They are lightweight, easy-to-install sheets that form excellent insulation of a concrete ceiling. Such boards are a good alternative to other materials such as the previously mentioned Styrofoam or ceiling insulation wool. They barely absorb water, can be processed without compromising thermal performance, and are resistant to micro-organisms and chemicals.

How to insulate an attic ceiling with PIR boards? Specific guidelines can be found in the manuals issued by the manufacturers of selected products. PIR boards are installed on horizontal planes in a fashion similar to how Styrofoam is installed. Insulating a ceiling of a non-usable and non-heated attic is not difficult. First you have to protect the base with a sheet of thermal insulation foil, and then install the boards in such a way that their edges overlap. Protect the ready-made layers with insulation foil and then cover with concrete.

How to insulate a wooden ceiling with a foam?

The use of Styrofoam or wool for a wooden ceiling in an old building does not always make sense. How to place insulation on a wooden ceiling in a non-usable attic when the surfaces are not even and many areas are hard to reach? In such a case, the only effective solution is to insulate the attic ceiling with PIR foam. It is a type of sprayed, two-component thermal insulation designed for various types of surfaces. Examples of such material are the Crossin® Wall Foam and Crossin® Floor systems intended for the production of closed-cell rigid foam.

Why should we use polyurethane ceiling insulation in the attic? The foam penetrates into each and every gap in the ceiling to form a rigid and dense coating. The material has exceptional adherence to wood and is an effective way to insulate a wooden ceiling in an old house. PIR foam provides thermal insulation, acts as a waterproofing membrane and sound barrier, and withstands attack by pests and fungi.

Insulating a reinforced-concrete ceiling: practical guidance

How do you insulate a reinforced-concrete ceiling and prevent the formation of thermal bridges? Whether you choose to insulate your ceiling with mineral wool, Styrofoam or PIR boards, you should maintain the appropriate thickness of the thermal insulation layers. To insulate a wooden ceiling in a non-usable attic, you normally need two layers of insulating material, which should additionally be protected with special thermal insulation foils. Between the usable storeys and in floors with underfloor heating, additionally use two layers of attic ceiling insulation.

What to use to insulate the ceiling in the attic: summary

Without a doubt, it is worth investing in energy-efficient solutions and insulation of the ceiling in the attic. Insulating materials provide tightness for buildings and allow you to maintain optimum room temperature in winter and in summer. Nowadays the range of products for insulating wooden and concrete ceilings is very wide, so you can easily pick one suited to your needs and budget.