The walls

The walls are the larger areas of the isolation, and for that reason, the components responsible for the most soundproofing work. Moreover, one of the walls is the weakest point of this isolation, since it has the door.

The walls were carefully designed to fit the exact measurements of the bricks to use. The aim was to avoid the necessity of having to cut bricks. The door was also designed so it's size was the most accurate possible in relation to the brick's measures. In a normal construction, the walls are built without great care, and when it reaches the extent of the door, the bricks are cut in order to maintain the desired shape. Moreover, all the electric installation is also placed later, which means, cutting the grooves for the tubing after the wall is constructed. In this case, this technique would not be acceptable because not only compromise the wall finish, as its acoustic performance.

Another important aspect is that the wall is not resting on the floor or have any elements that connect it rigidly to the building structure.

Mineral wool glued to the exterior wall.

The first step was to isolate the outer wall acoustically. This wall is part of the building and can not be removed in order to be properly isolated. Therefore, it was isolated with medium density mineral wool, about 70kg/m3. The acoustic sense changed radically after this application; upon entering the room, almost all exterior sound disappeared, but in an uncomfortably way, because it was absorbing too much reverberation in the room: the room was to "dry".

Gluing the mineral wool to the wall.

The application was made with glue. The mineral wool is not a solid material and there are the risk of get loose, but there was no possibility of using screws to fix it to the wall. The mineral wool is there to avoid vibrations of the outer wall being transmitted, and any screw would transmit these vibrations to the interior through the head of the screw.

The second step was to prepare the surface on which the wall rests. The inner wall is floated so there is no vibration transmition from the building to the wall.

First row of bricks to set the alignment.

One row of bricks was place and adjusted like the design on the project. Note that the door frame was previously built and used to perfectly align the bricks. With reference to this alignment, the felt was cut and placed on site with the first brick's row above.

Glued bricks.

After some tinkering and small tuning their positions, the bricks were fixed with glue between them.

Adding sand to the brick.

After the glue cure, the bricks were filled with sand. The process was repeated on each row to the top.

Boxes and tubing for the power sockets.

The technical boxes and tubes for electric sockets were installed when the elevation has been reached, thereby preventing further opening of the wall. Note that the brick is already the finished wall and therefore can not be damaged.

Four bricks were drilled with the diameter of the boxes for the outlets. These were fitted with tubing connection therebetween, and then cemented to maintain the boxes fixed. There are only four bricks with cement across the structure.

Do not forget that this structure is very heavy. Each wall is about 5 tons and does not cause damage to the building because underneath there is the planet earth. It would never be possible to build this room on the first floor without structurally reinforcing the slab. This weight can damage the building if it is not prepared to endure such a weight.

If the studio had to be built up at the first floor, other isolation technique had to be used, lighter, but at the same time, bulkier and more space consuming.