Basement music studio conversion

OVERVIEW

Converting A Terraced Basement Into A Drum Practice Room

Background Of The Project

The Soundproofing Store were contacted by a client who is a full-time professional drummer and drum tutor. The client had recently moved into a new terraced house. A very old property dating back to the Victorian period.

Being a professional drummer the client needs to practice regularly every day to keep his skill level maintained, he also privately tutors pupils at home.

Now, this is a problem for anybody in a terraced house but made harder as the next door neighbours work night shifts and need to sleep in the daytime!

The clients plan was to utilize the unused basement in the property by damp proofing and then soundproofing, converting the basement into a fully soundproofed basement studio. His main worry being that the soundproofing needed to be of the highest level, as any noise that could travel through the thin, single brick party wall, would result in him still not being able to use the room.

The Basement

The basement was large and with very low ceilings (as expected). The staircase down to the basement divided the area into two halves. The client was hoping to turn one half into the studio and the other half could be used as a lounge area.

The studio half was also then divided by another brick wall, splitting that half into two small rooms.

The Plan - Construction / Layout

The client had brought in a local, well respected building firm who are specialists in basement conversions. http://backtobasement.co.uk/ (Leeds)

Together we discussed the initial plan in terms of construction to be the following.

Knock down the dividing wall in the studio half, opening it up into one larger room.
Dig down into the concrete floor as far as we could go to lower the floor and therefore raise the ceiling height.
Block up the dividing wall separating the two halves of the basement leaving one doorway into the studio.
Tank the room using a damp proof membrane.

The Plan - Soundproofing

The original specification for the soundproofing was as follows:

Build a “room within a room” which is made up of high mass materials to block airborne sound from escaping. These layers need to be de-coupled from the structure and able to absorb vibration so that the sound vibration energy can’t transfer through into the structure of the building.

Walls

Create secondary, internal walls by using the full ReductoClip system . This involves building a 50mm timber frame (for minimal space loss) in front of every wall. The timber frames would be isolated around the perimeter using our Isolation strip to create a floating frame.

The frame is filled with a 50mm 60kg acoustic mineral wool to absorb sound within the cavity (created by the timber frame).

ReductoClips and furring channels are then attached.

Then re-build the wall layers using two layers of 15mm acoustic grade plasterboard sandwiching a layer of FlexiSound 5.

The plasterboard and FlexiSound adds a whopping 35.6kg of mass per m² to the walls.

The ReductoClips separate the solid wall layers form the timber frame, and absorb huge amounts of vibration energy, converting it into heat, and stopping the vibration from travelling into the solid wall behind.

Ceiling

Lower the basement floor enough to also use the ReductoClip system on the ceiling. Filling the ceiling void with 60kg acoustic mineral wool, then installing the ReductoClips on the bottom of the ceiling joists, and again using two layers of 15mm acoustic grade plasterboard with Tecsound SY100 or FlexiSound.

A concern was that above is just bare wooden floorboards with very little mass, lots of gaps between boards, and no other flooring. Ideally, we would want to add more mass to the floor above to really get a great result. However, the priority in this case is sound leaking into the adjoining properties not travelling above into the rest of the house, and the client preferred to keep his exposed wooden floors.

Floor

No need to add mass to the floor as it’s a concrete foundation with nothing below. However, we do want to absorb vibration. If we don’t address the floor, then the vibration will get into the concrete floor and spread under the soundproofing and into the structure. In this case ProSound ImpactoMat 5mm is all that’s needed.

Doors

A double fire door system. Using two FD60 rated, solid core fire doors, back to back, with a seal around the perimeter. Combined, the doors will have enough mass to block a high level of airborne sound.

Important Amendment To The Original Specification

Just before work was due to get started, the client got in touch as he was worrying that after all the work and expense of the studio build, what if the sound is still getting through to next door? The ReductoClip system is very high performing, and offers a very significant reduction, but at the same time, if only installed on a single brick party wall, with potentially over 100dB of sound, there is a chance the neighbour may still hear a very low, muffled sound still coming through.

Determined to block as much as possible, we discussed ideas to push the performance even higher than we have ever specified before for a studio project.

The plan was to line the brick wall with our ProSound™ SoundMat 3 before building the ReductoClip system in front. This would be pinned to the walls in overlapping tiles by rawl plugs. The SoundMat 3 is designed as a floor solution but is made up of 2 layers of very heavy, dense, mass loaded vinyl, separated by a vibration dampening foam.

This would add another 12.5kg of mass per m² to the wall. Also, because mass loaded vinyl hadn't been used anywhere else in the build-up, it would block different frequencies of sound to the other materials, giving an even broader range of frequency blocking. This would achieve much more than adding more layers of plasterboard or Tecsound (or FlexiSound 5) which we had already used in the build-up.

The Build

The builders did a great job knocking down the separating wall, opening the studio room out, and digging down into the concrete floor. Gaining a lot of height and getting the height to the ceiling joists at roughly 2.4 metres. So once the new ReductoClip Ceiling is installed, this would bring the ceiling height down to roughly 2.34m.

The builders poured a new cement floor to achieve a flat and even base, and left channels for the damp proofing. Then lined the walls with a damp proofing membrane. Not something we see much of in studio builds, as most tend to be ground level, but this was very important with it being a basement conversion.

Other Important Things To Consider

Power Sockets

One major problem in some builds is that after adding all of this extra mass onto the internal walls, the builder then cuts lots of big holes in it for cabling, power sockets and light switches. These holes then allow sound to leak through creating a weak point in the soundproofing.

Solution

Ideally have your sockets and switches surface mounted on top of the walls instead of inside the walls. This saves having big holes! It may not look as pretty as a nice flush, counter sunk socket, but with studios we are looking for maximum performance.

In terms of cabling, if your sockets are surface mounted, you only need a small hole in your wall to pull through cables, seal around the cable and fix your socket on top. Or... even better.... have your cables surface mounted as well (use plastic trunking). This is going to be much easier for cable management as well.

If you absolutely must have your sockets sunk in the wall and need to cut holes in the soundproofing, you can at least minimise the problem by covering the back of the socket box or inside of the socket box with our Socket Putty Pads

Lighting

As with sockets, a lot of people like to use nice flush spotlights inside the ceiling. These look great, but again require lots of holes to be cut out of your ceiling soundproofing.

Instead, go for traditional pendulum style lighting, requiring just a small hole for one cable, or surface mounted spotlights, or even free standing lamps which can be moved as needed and actually be very handy.

Ventilation

Materials that block sound also block heat, so a soundproof room can get very hot! At the same time, a well soundproofed room is relatively air tight, reducing natural airflow. So ventilation is important if you use your studio for long periods.

There are two choices. A simple in and out, passive vent such as our Acoustic Vent or a fancy digital, motorized vent/air conditioner unit. In this case the customer opted for a fancy digital system that controlled the airflow and temperature.

Cutting a hole in your wall for a vent will allow sound to leak out. The Soundproofing Store acoustic vent has a layer of absorption material inside to absorb some of the sound passing through. You can go a step further by building an acoustic vent baffle. This forces the air to bounce around a maze type box which is lined with absorbing material. As the air passes through the sound bounces off these surfaces and gets absorbed.

In this instance there was no need for a baffle, as the vent opened onto a quiet side of the property and wasn't an issue.

Acoustic Treatment

All the heavy mass loaded materials we have fixed to the ceiling and walls are very reflective for sound waves. This creates a space with a lot of echo which isn't great for a rehearsal or recording space.

The room needs to be acoustically treated internally to absorb the echo and reflected soundwaves, to create an acoustically optimised space.

The Soundproofing Store have a selection of Class A Acoustic Panels which can be fixed to the walls or suspended from ceilings to achieve this.