Why are pumice stones lightweight

Solid building materials

Solid and durable: bricks, aerated and lightweight concrete and sand-lime brick are still the most popular wall building materials. We explain the common construction methods.

Solid houses enjoy a high priority in this country. The solid construction results in only low maintenance costs in the long term and the long service life ensures that it retains its value. The continuously high market share confirms this. A study by DIA Consulting AG on the value development of single and two-family houses comes to the same conclusion. Every second builder chooses a stone house. All solid wall building materials are made from the local mineral raw materials sand, gravel, clay and lime. This results in heavy building materials with high heat storage masses, which for a balanced room climate in winter as in summer. The crowd guarantees the good at the same time Soundproofing: A criterion that many builders really appreciate.

A house made of stone also easily withstands the requirements of the Energy Saving Ordinance EnEV. However, the air and wind tightness as well as thermal bridges are increasingly coming into focus. Brick walls are windproof due to the building material. There can be no cracks or gaps through which the heat can escape. Energy losses through thermal bridges can be drastically minimized by using special elements. Examples are already thermally insulated flat lintels, U-shells or roller shutter boxes.

With a view to the wallet, there is a suitable solution for everyone, from turnkey offers to interior houses to complete shell kits with a high proportion of personal contribution. On the processing side, manufacturers have been offering modern, cost-saving product systems that can be used efficiently for years. There are well-engineered systems of labor-saving, coordinated masonry blocks on the market that meet the most diverse requirements for “shell construction from a single source”.

State-of-the-art are large-format block or plane bricks with tongue and groove design, which make butt joint grouting superfluous. Elementary construction methods are also becoming increasingly popular. The degree of prefabrication at the factory saves time and money on the construction site and ranges from storey-high to fixed and finished wall elements. In general, the design does not set any limits to individual architecture. A solid house is an investment in the future that can be sold well in an emergency. It is comfortable and economical and also offers a high level of safety in the event of fire. Because masonry does not burn, which has a positive effect on the insurance premium.

Brief portraits of the most common solid wall construction materials

Masonry bricks

Most solid houses are still built from bricks. Behind this are properties such as high thermal insulation and compressive strength as well as the pleasant room climate due to the moisture-regulating effect. The blanks are fired from clay at approx. 1000 degrees. Firing leads to the permanent ceramic structure, which is why bricks hardly shrink later. Porosing additives in the raw mass are the reason for the good thermal protection. In addition, the heavy components of the solid construction also guarantee a high level of windproofness.

Aerated concrete

The solid building material, also known as lightweight, is made up of quartz-containing sand and cement or lime. The raw mass is inflated with aluminum powder and hardened at 200 degrees. Millions of the finest air pores are created, which ensure excellent insulation values. Even a single, 30 cm thick wall meets the EnEV standard. Because of its low weight, this building material is predestined for self-builders.

Sand-lime brick

The starting material for the white stones is a mixture of lime, sand and water. The raw mass is pressed into molds and hardened at 200 degrees under steam pressure. The resulting dense and heavy material is very pressure-resistant and provides excellent protection against noise. The slim, highly insulated KS outer wall is recommended as a future-oriented wall construction. The low wall thickness also brings more living space.

Light concrete / pumice stones

Lightweight concrete consists of cement and water and - for the purpose of better thermal insulation - a porous aggregate. Pumice or clay are common. Pumice is a light, porous natural rock of volcanic origin with a high grain strength. The finished wall construction material is therefore pressure-resistant, sound-insulating and heat-insulating. Due to the continuously developed stone technology, stones with lambda peak values ​​of 0.11 (W / mK) are on the market today.

Lightweight concrete / expanded clay

For expanded clay, clay is burned in long, rotating kilns. This creates many small, puffed-up clay balls with a surface that has been sealed by the action of heat (sintering). The countless air pores under the ceramic bowl ensure the best insulation effects. Thanks to improved technologies, the thermal insulation values ​​of the stones in expanded clay have been improved by around 20 percent in recent years. The dense material structure is pressure-resistant and also protects against sound.

Typical wall constructions at a glance

Bricks:
Lime-gypsum 1.5 cm, single-shell flat brick masonry 36.5 cm, mineral light plaster 2 cm

Aerated concrete:
Gypsum plaster 1 cm, aerated concrete wall element 30 cm, lime cement plaster 1.5 cm

Sand-lime brick:
Interior plaster 1.5 cm, sand-lime brick 17.5 cm, full thermal insulation 10 cm, exterior plaster 1 cm

Pumice:
Gypsum interior plaster 1 cm, pumice masonry 36.5 cm, lime cement scratch plaster 2 cm

Expanded clay:
Interior plaster 1.5 cm, expanded clay masonry 36 cm, exterior plaster 2 cm

No mix of materials

Make sure that your solid house is not built from mixed masonry if possible.

This avoids cracks and thermal bridges. Because: The building materials differ in their material-specific properties as well as in terms of their shrinkage and creep behavior. The consequence of this is tension in the plaster base, and deviating thermal conductivity values ​​can cause condensation to form on the interior walls of the room.

Keywords solid house construction