One of the most common soundproof
walls that can be built, using materials right out of
the local home building store is to add sound deadening
board to the faces of the studs. This is a good way of
soundproofing a wall. Sound deadening board costs about
$0.25 per sq ft. If it is added to both sides of a wall,
which is the proper way to do it, the added material cost
is $0.50 per sq ft of wall. This construction method satisfies
all requirements of soundproofing. It reduces the airborne
clatter inside the wall, it adds a gap of material between
the gypboard and the stud which breaks the conduction
of sound path. Sound deadening board reduces the strength
of wall twang, the plate vibration and it can also contribute
structural damping to the wall shudder effect. It generally
satisfies all the requirements for making a soundproof
wall.
So, what is wrong with using sound
deadening board in construction of walls? Glue. The only
way sound deadening board can actually "work"
when the wall moves from vibration is if the soundboard
is glued to the studs on one side and again, glued to
the wallboard on the other side. In real life, the people
who build walls with soundboard leave out the glue. An
inner layer of sound deadening board that is not glued
into place is just a spacer and an expensive substitute
for fiberglass. There are three main reasons for leaving
the glue out of sound deadening board wall construction.
1. Most people doing construction
don't know that the glue is needed.
2. Buying glue costs extra money and applying it takes
a lot more time.
3. Getting glue to stick to vertical surfaces is messy,
to overhead surfaces, impossible.
As a result, most people don't even
consider trying to install soundboard with glue. And anyone
who actually does install soundboard correctly with glue,
only does the job once and swears to never do it again.
To properly glue soundboard to the
face of the studs and the plates, it must be covered with
a zigzag strip of 1/4" panel adhesive. Once the panel
is up, the same zigzag pattern has to be applied to the
soundboard directly over where the studs and plates are
located. Then the gypboard is placed over the soundboard.
To apply glue in a zigzag pattern one 10 oz tube of adhesive
will cover 24 feet of stud face. The overall glue cost
will be at least $0.15/sq ft for a wall with soundboard
on both sides. Soundboard itself costs about $0.22/sq
ft and if applied to both sides of the wall, the glue,
soundboard and tack nail expense is $0.70/sq ft. Add in
the basic cost of a gypboard stud wall $0.65 and the glued
soundboard version of a sound proof wall has a material
cost of $1.35/sq ft. The material cost for a soundproof
wall built with soundboard at about $1.35/sq ft is about
75% of the cost of a fiberglass/WallDamp wall which costs
about $1.78 per sq ft. Current pricing may vary, but you
get the idea.
The fiberglass/WallDamp wall is 1/3rd
more expensive than a soundboard constructed wall. And
so, one naturally wonders if there is an added value to
a WallDamp wall that is worth the extra expense over a
soundboard wall. The answer is found in the labor costs
to build the two walls. A soundboard wall, built right,
takes more than twice as long to build up as a WallDamp
wall. The materials cost benefit of soundboard construction
is more than made up for in the added labor on the job
due to the handling of glue and soundboard. For a contractor
who primarily makes a living by selling labor, building
a wall that has a lower materials cost but a high labor
cost is just good business.
Let's look at the soundboard installation.
A pallet of gypboard arrives at the job site. A second
and equal volume pallet of soundboard also arrives on
the job site. Then one whole layer of 1/2" material,
the soundboard, is hauled in, cut up and stapled onto
the framed walls. Next, another whole layer of 1/2"
material, the wallboard, is hauled in, cut up and screwed
down to the framed walls. The labor of laying up the wall
boards is twice as high because there are twice as many
wall boards being installed. And this describes the standard
soundboard wall construction method that doesn't work
because the glue was left out of the job. A proper soundboard
project includes gluing soundboard to the studs and gluing
wallboard to the soundboard.
In addition to the extra labor of
working with glue and soundboard, is the consequence of
having a wall that is too thick, a full 1" thicker
than a standard wall because it has 1/2" soundboard
added to both sides of the wall framing. All electrical
boxes that mount into the wall have to be the deep box
model. Plumbing also has to accommodate the extra 1/2"
thick wall surface. Standard door jambs are made for a
4 1/2" thick interior wall and can't be used when
the walls are 5 1/2" thick. Here, the labor costs
of finishing an extra thick wall again are on the rise.
But with WallDamp, it's thickness
is only 1/20" and this causes a negligible increase
in overall wall thickness. The installation of WallDamp
is simple and clean. Just remove the release paper from
one side of the self adhesive sheet and stick it on to
the sides of the framing members. The only mess is a few
curls of the release paper on the floor. WallDamp installation
projects tend to be clean projects. The amount of WallDamp
material used to line out a whole room can be held in
one hand, unlike the volume of soundboard that is needed.
Soundboard occupies 720 times more volume than WallDamp
to do the same job.
And finally soundproofing is not only
good for the walls, it is good for the floor and the ceiling.
WallDamp sticks wherever it is placed and never falls
off, even when working upside down.
Material Costs for
Wall Construction
Panel Adhesive to glue gypboard, soundboard
and studs together, both sides, material cost is $0.15/sq
ft.
The contractor price for ready to
paint 2 x 4 framed wall that is 8' high and with gypboard
on both sides is about $42 /lineal foot. This amounts
to $5.25/sq ft wall area.
It costs $2.55/sq ft to build a stud
wall in place, labor and materials.
It costs $0.75/sq ft to hang gypboard
onto an existing set of studs, labor and materials.
It costs $0.50/sq ft to staple R-11
insulation into the cavities of a stud wall, labor and
materials.
It costs $0.60/sq ft to hang soundboard
onto an existing set of studs, labor and materials.
It costs $0.60/sq ft to tape and texture
a gypboard wall to get it paint ready.
It costs $1.20 to glue soundboard,
studs and gypboard together, labor and material
A 2 x 4 wall with R-11 insulation
inside and gypboard on both sides costs $5.75/sq ft, labor
and materials.
A 2 x 4 wall with soundboard on both
sides covered by gypboard costs $6.45/sq ft, and this
does not include the glue step but otherwise, labor and
materials.
A 2 x 4 wall with soundboard glued
to the framing and with the gypboard glued to the soundboard
on both sides will cost $7.65/sq ft, labor and materials.
A 2 x 4 wall with WallDamp on the
framing and R-11 inside, covered with gypboard on both
sides costs $6.25/sq ft, labor and materials.
The WallDamp built wall is slightly
less expensive to build than the standard soundboard wall
and a lot less expensive than a soundproof version of
a soundboard wall, labor and materials.
