Poor soundproofing of ceiling against the upstairs neighbors is the most common problem encountered by our customers. Tramping upstairs, falling objects, moving furniture and other impact noises are the top irritants. And this is not surprising: the improper construction of the floor in the upstairs neighbors’ apartment may result in excessing the standard values for as much as 20 dB! The airborne noise from upstairs worries not so often. The modern reinforced concrete floors comply with the norms of Building Codes and Regulations (SNiP) but at the limit. However, such floors cannot also protect from the loud noise from the upstairs like the endless quarrels, playing the piano or the home theater.
EFFECTIVENESS OF CEILING SOUNDPROOFING
The effectiveness of ceiling soundproofing may vary depending on the type of housing. The fact is that sound transmission may be direct or indirect.
Direct transmission means that the noise propagates through the enclosure directly separating your premises from the neighbors. In the case of noise from the upstairs, this enclosure is a floor slab.
Indirect transmission means that the noise propagates through the adjacent surfaces: through the walls or the pipes or even through the floor.
The main problem associated with the ceiling soundproofing is indirect sound transmission through the walls. Because of the indirect transmission, the ceiling soundproofing only is generally insufficient for removing the noise from the upstairs!
The intensity of the indirect noise transmission depends on the material and thickness of the walls. For example, the sound cannot practically transmit through the thick brick walls, but the noise emission of walls made from foam concrete blocks, plasterboard or gypsum partition blocks is very strong. That’s why the brick house ceiling soundproofing is able to completely eliminate the problem of noise from the upstairs. But soundproofing the ceiling in the monolithic or bearing-wall houses can solve the problem only partially by reducing the noise to a comfortable level.
CEILING PREPARATION
If even a normal conversation from the upstairs can be heard, then the floor structure is most likely defective. The joints between the plates (the rustication joints) which have been tight initially, deteriorate over the years and the gaps which form in them significantly reduce the ceiling soundproofing! Inspect the ceiling before starting the sound insulation works. If gaps are found, stuff them to the full depth with the oakum and seal with a silicone sealant.
Another problem area reducing the sound insulation is the flow risers.
The pipes are practically always encircled with the holes for the entire depth of the floor structure; these holes may be invisible sometimes under the cement grout. Tap the ceiling near the pipes: the booming sound means that there is a void inside probably.
In this case, it is better to break the ceiling in this point, then seal the hole with small pieces of MaxForte-ECOslab and plaster it!
Never use the conventional construction foam for sealing the gaps and the holes! Due to its low density, the foam cannot not delay the sound, while the solidified foam becomes stiff and transmits the vibrations. The “soundproofing” properties of conventional construction foams are the very common myth cultivated by illiterate workers.
The only exception are the special high density soundproofing foams – for example, the Maxforte SoundFLEX. Such polyurethane foams retain the high elasticity after drying. This property is critical for high-quality vibration insulation!
Before starting the works on the ceiling soundproofing, the internal non-bearing walls should be necessarily isolated from the floor structure. Let us remind that the noise can be transmitted strongly via the light walls made from the foam concrete blocks, gypsum partition blocks or plasterboard. The building regulations require that the walls made from the foam concrete blocks or the gypsum partition blocks do not directly touch the ceiling, otherwise the plate movements can easily damage such internal walls. If the rigid constraint actually presents, then the grooves should be made in the walls along the ceiling. The gap between the wall and the ceiling is foamed sometimes. In this case, the foam should be dismantled. In any case, the resulting gap should be tightly filled with small pieces of MaxForte-ECOslab, and the resulting joint can be packed with the non-shrinking plaster or filled with the sealant. Such simple measures will significantly improve the effectiveness of the ceiling soundproofing!
CHOOSING THE OPTIMAL STRUCTURE
As in the case of the walls, the ceiling can be soundproofed with either framed or frameless systems. Our company offers the ceiling sound insulation based on the framed systems since they have several advantages, namely:
- Framed systems level automatically the surface of the ceiling. When mounting the profiles, the workers will set a plane to which the plasterboard will be attached. Frameless systems completely repeat the ceiling shape. Therefore the ceiling needs to be leveled before mounting the panels, and this makes an additional cost!
- Fewer attachment points. In narrow rooms up to three meters in width, the profile can be tightly installed between the walls absolutely without attachment to the ceiling. But even if such attachment is necessary (room is more than 3 meters in width or significant loads are planned), the framed systems require the 3-4 times less number of the attachment points in comparison with the frameless systems. Although the attachment points are vibration-insulated, it must be understood that no elastomer can completely remove the vibration load. So the less the attachments, the better!
- The metal-framed suspended ceiling has a large carrying capacity. A luster or a projector can be hung to the profile. The ceilings themselves can be made two-level.
- If the framed systems are used, the wiring, the ventilation systems and the other communications can be easily mounted.
- The ceiling sound insulation can be mounted on the frame by any worker engaged in the repair of apartments since the standard KNAUF construction technology is used.
The effectiveness of the ceiling soundproofing against the upstairs noise depends not only on the proper choice of sound-absorbing materials but it is also very important to minimize the vibration load at the points of profiles attachment to the floor structure. For vibration isolation of the frame, a damping layer MaxForte-SoundPRO or the special vibration insulating hangers (for example, VibroStop PRO) can be used.
FLOOR SOUNDPROOFING AT NEIGHBORS
Another way to control the noise from the upstairs is to soundproof the floor in the apartment above you. Proper floor soundproofing will allow you to completely solve the problem of both impact and airborne noises. In the new building, the simplest solution would be to reach an agreement with a neighbor about sound insulation of the floor in his apartment before the screed pouring. The noise isolation of the floor in a neighbor's apartment will cost less money and, what’s the most important, will be more efficient because all the noises will be isolated at their source! In addition, since the sound insulation is mounted at your neighbor, the entire height of your ceiling will be saved!
You can act in the similar way in the case of the finished repairs, but the question is whether the upstairs neighbors would agree to rework the floor in their apartment. The experience shows that not everyone agrees!
The standard solution for the ceiling soundproofing is a suspended drywall ceiling filled with sound-absorbing materials. The thickness of the structure can vary over a wide range: from 4 cm in the thinnest option to 12 cm for sound insulation against the neighbor’s home theater.