How to prepare openings for window on the construction site?

A fundamental element of the installation of a window or a gate is the prior preparation of the place of their fitting. What should we take care of?
We explain step by step:

Step 1: The reveal should be cleaned of loose building materials. Make sure that they are smooth and even, and any defects should be filled with appropriate mortar.

Step 2: We recommend reinforcing the reveals with a primer that will ensure proper adhesion for the sealing materials.


TIP: In the case of ceramic blocks it is very important to seal the openings in the horizontal part of the recess, which in the further stage of construction will exclude the possibility of ventilation (mesh + mesh adhesive).

In case of applying external sealing in the form of vapour permeable window tape, the external surface of the wall should be levelled in order to maintain proper adhesion of the tape.

Step 3: Remember to maintain the appropriate expansion gap depending on the type of installation and the type of recess (should not exceed 30 mm); too small gaps may lead to deformation of the profile and problems with opening the window, while too large gaps weaken the mounting of the window.

Step 4: It is very important to create a foundation or use system extensions for terrace, sliding and balcony windows fixed in the face with the floor level. In the case of using thermal sub-window materials such as warm window sills or thermal sub-framework, level the reveal.

Step 5: It is also worth considering a recessed lintel allowing the use of insulation at the height of a concealed roller shutter box, if such a cover is planned.

IMPORTANT: Installation conditions are very important already at the design stage. Considering the right place at this stage will help avoid problems with window selection “after the fact”, i.e. when the walls are already standing.