Wave Form and the vertical hanging guide: blade count, spacing, drop and the two ways to hang.
Vertical is the orientation that takes real planning. Here is the method, how to size a run of felt baffles and the two ways to hang it.
Where the last guide left off.
In our guide to the three types of acoustic ceiling we set out how a felt panel hangs, horizontal, vertical or interconnected, and which suits a space. Two of the three are quick to plan. Horizontal and interconnected come as a coverage area and hang on a handful of wires. Vertical is the involved one. It is a set of separate blades, so you size it and hang it yourself.
This guide is that method. By the end you will be able to size a run of vertical baffles and choose how to hang it. The felt shown is Wave Form, but the method holds for the whole vertical family.
What counts as vertical.
Vertical means the felt stands on its edge, faces to the walls, set in rows. Wave Form leads it, the sine, compound and skewed cuts. Alongside sit the plain oblong blades and the flowing Drift and Boardwalk profiles. They look different from below, but they all hang the same way and they are sized and fixed by the same method. So everything here applies across the family, whichever profile you choose.
How a run of baffles works.
Sound in a room goes through three stages. It is made, it travels and some of it reaches the ear. A hard flat ceiling sends the travelling sound straight back down, and in a room with hard floors and glass those reflections build up and make speech harder to follow.
A run of felt baffles works on the middle stage, the travel. The felt is a soft open surface hung in the room with both faces exposed. Sound that rises to the ceiling meets the felt and loses energy in it, so less of it comes back down onto the people below. The direct sound still crosses between people, the baffles are not a barrier. What they take out is the reflection off the bare ceiling.
One limit. Baffles absorb sound within a room. They do not stop it passing through a wall or between floors. For a live, echoey room they are the right tool. For a neighbour through a party wall they are not.
There is a placement point too. Where the sound has a clear direction, a room with a front such as a lecture room or a presentation space, run the rows so the blades face the travelling sound. More felt turned to the sound means more of it absorbed as it passes.
Blade count.
Start with how many blades. This is the lever that does most of the work. More felt in the room means more absorption, and blade count is how you add felt. Set it by the area you want to treat and how hard the room is. A busy open floor or a glassy, hard room wants more. A smaller or softer room wants less. Count and spacing are two sides of one decision, so fix a rough count here then settle it against the spacing below.
Spacing.
Spacing is how far apart the blades sit, measured centre to centre. Tighter spacing puts more felt in the same area, so it absorbs more and reads more solid from below. Wider spacing is lighter to look at and costs less. On a suspension channel the pitch is set for you. A 2400mm channel seats eight leaves along its length, which puts them at 300mm centres. On individual wires you set the pitch yourself, tighter or wider as the room needs.
Drop.
Drop is how far the run hangs below the structural ceiling, measured to the top of the blade. In a standard-height room keep the drop short, enough to clear head height and read as a deliberate feature. In a tall volume drop the run further, so the felt comes down into the room where the sound is rather than sitting lost near a high ceiling. The blades do the same work at any drop. Drop is about where you place them in the room.
The two ways to hang.
There are two ways to carry a vertical run.
- Individual wires. Each blade hangs on its own pair of wires. The wires adjust, so every blade can be levelled on its own. This gives the most control and the most fixing points.
- Suspension channel. The blades are cut to feed into a metal channel, and the channel is hung instead of each blade. One channel carries a whole row, so the ceiling takes far fewer fixings. A 2400mm channel holds eight leaves, a 1200mm channel holds four, and each channel comes with one pair of wires. The count is the same whether the felt is 12mm or 24mm.
The channel is how you cut the fixings down. Eight blades on individual wires need sixteen wires, a pair each. Feed the same eight into two channels and the run hangs on four, a pair per channel. That is the standard install, two channels to a run so each blade is carried at two points, four wires to the ceiling.
For an integrated ceiling of intersecting baffles, space the hanging points evenly and fix the wires at the joints where the panels cross, the same cross-lap principle as the interconnected hang in the last guide.
Sizing one run, end to end.
Take a run over a meeting table, a zone about 2.4m long.
- Blade count. Eight blades covers it.
- Spacing. Feed them into 2400mm channels and they sit at 300mm centres, an even run the length of the table.
- Drop. The room is standard height, so a short drop clears head height and keeps the run reading as a feature. In a taller room you would drop it further.
- Hang. Two channels, one toward each end of the blades, so every blade is carried at two points. The run hangs on four wires, a pair per channel.
Now tally the wires. The same eight blades on individual wires would need sixteen, two per blade. On the two channels it is four. Same felt, same absorption, a quarter of the fixings.
Frequently asked questions.
How far apart should baffles be?
It is your choice, measured centre to centre. Tighter absorbs more and reads more solid, wider is lighter and costs less. On a 2400mm suspension channel the leaves sit at 300mm centres. On individual wires you set the pitch yourself.
How far should baffles drop?
Enough to clear head height in a standard room, further in a tall one to bring the felt down to where the sound is. The blades work the same at any drop.
Can I level the blades after hanging?
On individual wires, yes. Each blade hangs on its own adjustable wires, so you can level them one by one. On a channel the row is carried together.
Should I use wires or a channel?
A channel for fewer fixings and a tidy ceiling, individual wires for the most control over each blade. Most runs use a channel. It brings eight blades down from sixteen wires to four.
How many wires will I need?
On individual wires, two per blade. On channels, a pair per channel, and a standard run uses two channels, so four wires carry the run.
Do vertical baffles soundproof a room?
No. They absorb sound within a room and cut echo. They do not stop sound passing through a wall or between floors.
What is the measured performance?
The 24mm PET felt board is rated NRC 0.65, to EN ISO 354:2003, measured baffle-mounted with both faces exposed and no cavity behind, which is exactly how a vertical run hangs. Reaction to fire is Class B-s1,d0 to BS EN 13501-1.
