Q. We live in the first-floor condo of a recently renovated three-family. The unit is lovely with hardwood floors throughout and large windows. It seems the builder used cheap materials, though, because we can hear our upstairs neighbors quite well. Is there any soundproofing that can be applied between the floors to make this more bearable?
BOTHERED IN BROOKLINE
A. Can you persuade your upstairs neighbor to install carpets? That’s one simple and effective way to reduce noise, but your neighbor probably won’t want to cover those hardwood floors.
I think you’re dealing with reverberation, essentially the echo sound creates as it bounces off surfaces in a room rather than being absorbed. This often means installing acoustical wall and ceiling board, acoustical ceiling and wall tiles, covering hardwood floors with carpets, increasing insulation, installing commercially available coverings designed for noise control, or using commercially available vibration-isolation systems.
When thinking about how to soundproof a ceiling and wall, consider these four principles in your plan:
Adding this helps absorb the transmission of noise by providing a barrier to soak up and disrupt it. Add standard Fiberglas, acoustic, or recycled-cotton insulation. Use R13 in the walls and R19 in the ceiling.
Materials such as brick, thick glass, concrete, and metal all have high-density disrupting properties. Adding mass, such as double layers of drywall, to a wall or ceiling can help a little.
Sound absorption sucks up the noise like a sponge. Common sound-absorption materials include decoupled lead-based tiles, open-cell foams, and Fiberglas.
A common material is mass-loaded vinyl, which works great as a sound-transmission blocker on plumbing in ceilings and walls. We sometimes use it to deaden drains and water lines on our remodels. The damping mechanism works by extracting the vibration energy from the sheet and dissipating it as heat.
Mass-loaded vinyl is a dense PVC sheet with barium sulfate or calcium silicate to add weight. It’s a heavy product, weighing a pound per square foot, which it is effective at reducing airborne noise.
This prevents the transmission of vibration energy from a source to a receiver by introducing a flexible element or a physical break. Common vibration isolators are springs, rubber mounts, cork, etc. We see these items on air-conditioning units and other types of heating, ventilation, and air-condition (HVAC) systems mounted to rafters in residential buildings.
Vibration isolation is used in many types of household items, and you may not even realize it: pumps, motors, HVAC systems, washing machines, and high-end audio equipment.
Some readers wrote in with advice for Terri Loten of Marshfield, who was having cooling problems in her home (“Tips for improving your AC’s performance,” Aug. 14). They suggested that she close the downstairs air registers halfway because cool air settles. They said she should do the reverse when the heating season begins. Closing/dampering down the registers is certainly an idea I did not think of. Readers also suggested having an HVAC technician balance the system and install manual dampers that can be adjusted in the summer and fall. You Globe readers are so smart! Thank you. I hope Terri is reading this.Rob Robillard is a general contractor, carpenter, editor of AConcordCarpenter.com, and principal of a carpentry and renovation business. Send your questions to email@example.com or tweet them to @globeaddress or @robertrobillard.