Acoustics

No Noise is Good Noise

/ Scott / 1 Comment

A couple months ago, Jas hired me to help him soundproof his kitchen ceiling. We completed the first half over three partial days, working around each other’s availability. Recently I returned for one more day at Jas’s house and we made quick work of the second half.

Jas made a material run before I arrived, so we had all the necessary Advantech and drywall on hand. I resumed the familiar sequence: measure, cut, install. I planned out the pieces to ensure we staggered our joints (so a drywall seam never lined up with an Advantech seam) and left as few scraps as possible.

Advantech spans over the central beam.

Advantech spans over the central beam.

The central support beam posed a challenge. Floor joists landing on this beam did not quite line up with one another, so I cut the Advantech pieces narrow enough to just slide through the choke point. (We filled in the resulting triangular voids with skinny Advantech scraps, then cut the drywall to cover them.) Compounding our installation problem, the piece nearest the exterior wall needed to sneak its way over the convexity of that wall – it’s a log cabin, after all. In light of these difficulties, Jas and I dry-fit every single piece (and re-cut if necessary) before gluing and screwing to the ceiling.

Jas had a brilliant brainstorm to speed up the Advantech installation. Not only did we drill pilot holes for the 1½” screws, we also drilled the screws themselves partway into the wood before raising the piece to the ceiling. One hand on the drill and one hand to steady the piece… way easier than one hand holding the screw, trying to pin the piece against the ceiling with an elbow or neck. We also used our T-prop in lieu of a third pair of hands to keep the longest pieces from sagging.

Drilling the last few drywall screws.

Drilling the last few drywall screws.

The white drywall has brightened the kitchen and dining room considerably, and we can use trim to hide the rough edges if Jas wants. More importantly, he can clang pots without disturbing anyone upstairs. Our two layers of material and soundproofing glue really do wonders to absorb the noise.

Sounds Like a Good Idea

/ Scott / 2 Comments

Jas hired me for an interesting soundproofing project in his Mad River Valley cabin. Noise travels easily through the kitchen ceiling (which is also the second floor) and disturbs renters in the bedrooms upstairs. That is the problem we’re trying to fix.

Jas doesn’t want to hide his gorgeous exposed timber joists, so our acoustic solution consists of two extra layers of ceiling within each bay. The first layer, Advantech, ties adjacent floorboards together and stiffens the floor. The second layer, drywall, serves as a smooth paintable finish surface while providing additional thickness. Between the layers we sandwiched a healthy squeeze of acoustical glue for extra dampening.

Beautiful, rustic ceiling bays... one with a freshly-installed piece of Advantech.

Beautiful, rustic ceiling bays… one with a freshly-installed piece of Advantech.

First we measured and cut Advantech. In ideal circumstances, this task would be as simple as measuring the width and length of each bay… but built houses never present ideal circumstances. Our timber joists were slightly crooked, making each bay vary in width. Worse, there was a joint above the kitchen island where two joists butted end-to-end, and the two joists didn’t line up at all.

In many cases we settled for cutting the Advantech pieces narrower than the bays so they’d fit easily between the unruly timber joists. We did the same with the drywall later, varying the seam locations. The downside of this approach was leaving unsightly gaps alongside the timer joists, which we’ll have to hide later. “A little bit of spackle and paint/Make a carpenter what he ain’t.”

Jas screws drywall to the Advantech, with a T-stick supporting its weight.

Jas screws drywall to the Advantech, with a T-stick supporting its weight.

We had to balance each piece in place over our heads while one person drilled in the first few screws to hold it permanently. That was a challenge, especially for the densely-packed Advantech… we took to drilling pilot holes so the wood would accept screws more easily. Jas dreamed up a T-stick to prop up each piece from the floor, giving us a crucial extra hand on the largest pieces.

With only about one bay complete, we can’t yet gauge how effectively the system absorbs noise. Stay tuned to hear the final report.

One bay (almost) complete.

One bay (almost) complete.