There are several things that architects, construction companies and private building developers should take into account when constructing new buildings. The right building entries are crucial in order to achieve secure radon sealing in buildings.
The main focus should always be the functionality of the sealing. Radon expert Karin Leicht says it is particularly important to ensure that seals and penetrations have airtight connections and closures. On the construction site, this means paying very close attention to such precautions: after all, subsequent rectification is complex and costly.
For this reason, it is advisable to carry out advance testing on the subsoil and the surface in which the building entry is to be installed. No matter how well the building entry or wall entry is constructed: edge spalling – e.g. in concrete – can still result in leaks. This applies not just to radon but also to water entering buildings in this way. This is why it is important to ensure high-quality sealing when carrying out concreting work, especially when using building entry products. Regardless of whether the entries are installed in the floor or wall, they should be seamlessly surrounded by concrete without any cavities.
Up until now, rectangular recesses have often be used for floor slab entries. The floor slab was cast leaving a space for the entry, and this space was subsequently filled with fresh concrete. Since the older concrete does not bond seamlessly with the new concrete, gaps and cracks can form that allow both radon and moisture to enter the building. This is why it is vital to use a professional building entry. The Hauff-Technik tundish AT 110 is cast directly with the floor slab, ensuring the concrete seamlessly encloses the entry. This provides leakproof sealing from radon and moisture.
Private developers should also attach great importance to sealing their building, and they should follow up consistently with the consulting architect and/or construction company. In this way it is possible to counter any potential hazard source, especially considering that the issue of radon has not yet been fully taken on board by the construction industry. If sealing work is still not carried out professionally, the recommendation is to involve a building surveyor and if necessary consult a lawyer regarding legal enforcement.
Extra tip from Ronnie Radon: Hauff-Technik wall entries and building entries are an excellent option. Products such as the building package with the tundish AT 110 or KG-FIX are perfect for radon-proof penetration.
(Sources: Interview with Ms. Karin Leicht on 04.12.2018 and website of the Federal Office for Radiation Protection)