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Workshop Soundproofing

Summary

Do your neighbors hate you? have you often wondered what you could do about your workshop noise levels that might help the situation?

 

In this article, I am going to try give you some feedback on what it takes to reduce noise coming from your workshop and how best to approach it. The short answer is yes, there is quite a bit you can do to better your situation and the bad news is, depending on your current situation it can be expensive and unless you are willing to throw the kitchen sink at the problem the chances are at best you will get the noise reduced to a reasonable level that will allow you and your neighbors to still be friends.

 

I managed to reduce the noise levels coming from my workshop significantly. The total cost of the project was close to R15,000. It took me about 5 full days of work and a team of 3 guys, 3 full days of work to finish the ceiling. The total project was completed over the span of about 2 months. 

 

I didn’t know anything about reducing sound before this project and have agonized over every little detail of this project and can confidently say, there is more that can be done to my workshop BUT what I have done has been a good balance between cost and results and I am happy the project is finally done now. 

 

I have been woodworking to my heart’s content on weekends since this project finished about 2 months ago without a single complaint from any neighbors.   The numbers recorded in this article should really be used to show improvement and you shouldn’t place too much importance on the amount of improvement. The reason for this is that anecdotally I can tell you there is a massive difference, but this doesn’t reflect in the numbers because a cell phone microphone with a free decibel app is not designed for this sort of application. The fact that I got readings that showed some change in level at all was amazing. I would easily say that the numbers you see below would be fair to double or triple them if I had real equipment to do proper testing. It is also important to note that the decibel scale is exponential: 

Experiments have shown that an increase of somewhere between 5 and 10 dB will sound twice as loud: most people heard 5 dB as less than twice as loud.” 

 

Background

 

After 3 years of slowly building up my workshop I found myself at a crossroads where I really wanted to accumulate more tools but at the same time, I was enjoying my woodworking less and less each day after having several complaints from the neighbors about the noise I was making on the weekend.

My view may differ from yours as the forums on Facebook seem divided on this topic between trying to reduce noise and basically telling your neighbors to take a hike. I personally feel obligated to extend the same common courtesy to the community around me that I would expect from them. My weekends are my main workshop time and depending on what I am building I can completely sympathize with the people living around me. I know if the roles were reversed it would annoy me too if power tools were being used when I was trying to rest.

As a rule of thumb, I never used a power tool before 11am on either Sat or Sun and I Would try wrap up by 4pm. Unfortunately, the complaints got to me and it started effecting how I would approach my work. I started trying to batch operations into a small amount of time and then if I missed something, I almost felt bad that I had to fire up a router or table saw to complete a task. My woodworking became less and less enjoyable as I tried to sneakily build projects without making a noise.

Older picture of my workshop before any work was done.

Layout

 

A quick overview of the image below. I live in a mirrored house, not quite sure how to explain it but the blue and grey houses marked below are identical and share a common wall. My neighbor also owns the garage next to mine. Our relationship is great, and he has never once had any issue with my workshop.

The Flats have been the main problem, with 4 separate units that face my garage window. They have collectively complained a few times. As you can see with the yellow square on my drawing, there is a window that directly faces them, and they often come out to see if they can spot me in the workshop to tell me to stop.

House 1 has just had someone move in and he seems cool, has already asked if I could help him with some furniture.

House 2 / 3 have also had some issues with us although I must admit have not complained much about the workshop.

Soundproofing Layout
Basic layout of my garage and neighbors as well as the points I took noise readings from.

Approach

Once I had made the decision to try reduce the sound coming from my workshop it became clear that really needed to upskill on the subject. I knew absolutely nothing about sound proofing or sound reduction and once I started going down this rabbit hole it dawned on me that this is way outside of my comfort zone.

It was important to me to do this in a way that could be measurable and that I could possibly experiment with my own time and money that may save others in the long run by avoiding low value upgrades. I decided to use my phone and downloaded an app that would measure decibel levels. I would then take my vacuum cleaner which has a high frequency whine to it and use it as my control noise and measure DB levels at different points outside my workshop. I would then make changes to my workshop to improve the sound reduction and do the test again at each point to see how the change had impacted the noise reduction. The only downside to this approach is that obviously after each upgrade was done it would be more and more difficult to measure the effects of additional upgrades as there would be overlapping effectiveness of the soundproofing.

Control Results:

To keep things consistent the vacuum was placed in the middle of my workshop on the floor with nothing blocking its path to the garage door or window.

1. In the Workshop: 74db

2. Outside Workshop with Garage Door Open: 66db

3. Outside Workshop with Garage Door Closed: 53db

4. Alleyway: 53db

5: Outside Window in Alleyway:53db

 

 

My Workshop

 

As you can see from the layout, the garage is a very standard construction. It has a brick wall separating my garage from my neighbors garage and then obviously also brick on the side facing the flats. There is a window and roll up garage door. There is a very brittle portion of ceiling directly over my work area but otherwise the whole space is exposed to the roof with no ceiling covering the majority of the area. My neighbors garage has a ceiling which was lucky for me as it meant that after 2 years of woodworking no dust had travelled over the common wall onto his car.

Current Workshop
Workshop Before Changes
Roof - No Ceiling

Upgrade 1 – Foam Sealing on the Window Frame

My window frame is old and buggered, I wish I had taken more photos of it but there were massive gaps between the frame and the window. I went and bought some cheap foam strips to try my best to ensure at the very least a proper seal on the window.

I didn’t take any photos of this as it was pretty standard application however it had some surprisingly results. After adding it and redoing the test in the alley and at the window as those would be the only tests that mattered for this upgrade, I got the following:

4. Alleyway: 50db

5: Outside Window in Alleyway: 50db

 

A very cheap, quick upgrade had already shown a small db reduction but I could also notice the difference standing outside that it was quieter

 

 

Upgrade 2 – Insulated Plywood Walls

 

The next upgrade which I expected to have a massive improvement was to install full plywood sheets, packed with135mm think pink aerolite insulation up against the wall with the window. To be honest, I thought this would be the end of the journey and something like this would solve my problem. The most common fix on the forums was putting plywood sheets on your walls although I can say in my situation this had little to no effect.

 Man handling the full sheets and working with insulation is nasty stuff. I ended up placing some frames around the plywood, packing it with the insulation and then stapling on black plastic bags to keep it on the board and also to stop the fibres from floating around in my workshop.

I put two sheets and a part of a 3rd sheet to cover the wall and then I repeated the tests to see the effects:

4: Alleyway: 48db

5: Outside Window in Alleyway: 49db

 

At this stage I was devastated, although I had planned to put more sheets up around the workshop, I could see that they were having little to no effect on the noise reduction. The sheets and insulation came at a decent cost of time / money and I felt that I made less progress than a R80 foam strip in the previous upgrade. I almost abandoned the project and decided to leave it for a few days to see if I was still motivated to continue.

A few days later I went back and turned my vacuum on and went to stand in the alleyway and just sat there listening to it. After a while I started to realize that the sound was coming from the roof. I went back inside and poked the roof with a piece of wood and realized there was nothing but tiles between my workshop and the world. This was a good feeling as I thought there was room for improvement, but I also knew more costs were coming.

First Insulated Plywood Sheet Up
Second Plywood Sheet Goes Up

Upgrade 3 – New Ceiling

 

I decided to bite the bullet at this stage and install a ceiling. I knew it was going to cost quite a bit with no guarantee of any improvement, but I also knew that it was now or never to try my best to solve this or to rethink my workshop usage. I did some rough costing of materials and could get it done for about R5000 for materials alone, although when I really got into the detail of what needed to be done and how long it would take, I decided in the end to hire someone to come help me. There was just no way I would be able to do the job alone.

I hired a team of 3 guys who came and installed 12mm Rhinoboard ceiling, with two layers of 135mm Think Pink Insulation above it. The poor guys were in such a bad state after working with the insulation that I gave them all a big tip at the end of it. 

It took the guys 2 days to almost finish the job and then the Durban unrest hit, and it was put on hold for another 3 weeks. They finally finished the job, and I was so pleased with the results.

I repeated the following 3 tests to see the improvement and my word what a result, again the numbers don’t do it justice because there was a massive difference. at db levels of 40 – 45 you are picking up more ambient noise than anything in the workshop.

3. Outside Workshop with Garage Door Closed: 50db

4. Alleyway: 43db

5: Outside Window in Alleyway: 42db

Workshop Carnage
Light Installed
Double Layer - 135mm Think Pink Aerolite Insulation
Rhinoboards Going Up
Cornices Done

Upgrade 4 – Drywall Addition

 

I decided at this point to double up on the plywood sheets. I had some extra 6mm Rhinoboard  and decided to add it to the plywood on the walls. I am not sure it was really needed, but I had the boards and no other use for it and the more research I did, I realized that drywall has better sound reducing qualities than wood does. It has a higher density so I thought I couldn’t hurt to add it to the mix.

4. Alleyway: 43db

5: Outside Window in Alleyway: 42db

At this stage any tests done on the walls were difficult to judge, I had pretty much eliminated the noise in the alleyway and at the window with the plywood and the ceiling so it was difficult to tell how much effect the drywall had.

Drywall
6mm Rhinoboard Drywall

Upgrade 5 – Garage Door

 

The last upgrade I did was to address the Garage Door situation. This upgrade was a bit more of a challenge. My original thought was to create a curtain and pack it with think pink insulation and then when I was in the workshop I could close it and create a barrier between my work area and the garage door. The more I thought about this the less convinced I became that it would have a good effect.

I then spent a good few day’s planning to build two doors within the workshop that I would be able to close creating an internal additional wall between me and the garage door. The physics of this were difficult, it had to be able to close by missing the garage door motor, each door had to be long enough to meet in the middle and it needed to have no gaps and create a seal. The doors would be incredibly heavy and I needed to be find a way to  support the doors by wheels on the floor to be able to open and close them. My floor has a massive crack in it, so this was not going to work. The final decision to not do this was down to safety. The thought of having a sealed door and a garage between me and getting help if I had an accident seemed dangerous.

In the end I decided to go with 50mm High Density polystyrene which I could cut to fit in the slots within my garage door. I knew this wouldn’t be much of an improvement, but I did think it would help a bit and was relatively cheap and easy to install and wouldn’t put any noticeable additional strain on my garage door motor.

3. Outside Workshop with Garage Door Closed: 47db

 

The main problem with the Garage Door is there are always weak points where air can travel from my workshop to outside, so you can’t get good sound reduction until you address the gaps and the way my garage door opens makes it impossible to address them fully.

Garage Door Insulation
50mm High Density Polystyrene

Conclusion / Final Remarks

 

This whole exercise of reducing workshop noise was quite consuming. Once I got stuck into it I realized this really had no end and I had to be objective about what was an acceptable point to stop putting effort into it. I must admit, the possibility of having a workshop that I could use all weekend without worry was just such an inviting proposition. I lost quite a bit of sleep over planning this build, and my workshop was offline for almost two months as a lot of time was spent waiting for materials and time to do the jobs myself.

I am happy with the results; I have not created a sound isolation chamber…. there is still noise that my neighbors can hear but its manageable. It’s the difference between your neighbor mowing his grass at 7am on a Sunday and the dude at the end of the street who is mowing it at 9am. I can turn on my vacuum, air cleaner and table saw and stand outside my closed garage and have a conversation comfortably.

My advice for anyone going down the same route would be to start with the physical air gaps between your workshop and the outside space, if cash is not a blocker then double-glazed windows would make a huge difference. If you only use your workshop for woodworking and not to store a car, then seal up the garage door completely. Lastly, check your roof situation, once I addressed the biggest problem with my workshop I had pretty much solved 70% of the equation. It was obvious in the end but might not be for you starting out on your project. Find out what your ceiling is made of, find out if there is insulation above it. The density of Rhinoboard and thickness of insulation makes a huge difference.

Bonus Content

 

Well done for getting through a full article on sound proofing. I really hope you found it interesting or at least helpful in a way that may save you some time and money to avoid the mistakes I made and concentrate on the areas that will add value. 

Because you have made it this far in the article, I will share an interesting snippet from this project.

At the end of the day when the guys had been working on putting the ceiling in, I got a call from them at about 8pm that night.

“Hey chief…. I forgot to tell you, I found your gun in the rafters, I left it by the garage door”

This was concerning to me as I don’t own a gun. I went to the garage to find an old .22 rifle wrapped up in brown paper that had obviously been sitting in the rafters for who knows how long. The bolt and trigger mechanism have seized but it could be a fun restoration project. The reality though is that this thing is more a thorn in my side than anything else as it’s an unlicensed firearm that I now need to deal with by either trying to license it or handing it in to the police.

.22 Rifle
Old Rifle
.22 Rifle
Birmingham Small Arms
.22 Rifle
.22 Calibre

2 thoughts on “Workshop Soundproofing

  • 23 Aug 2021 at 3:41 pm
    Permalink

    Awesome read and a lot of useful advice! Quite a surprise you found in the ceiling too.

    Reply
  • 23 Nov 2021 at 12:23 am
    Permalink

    Very interesting to read about your experience indeed! I suppose you could say I approached the issue from the other side, as I was more concerned with the extreme heat inside the garage than with the noise I was making. I’m fortunate enough to have a free-standing double garage at my disposal, and the next-door neighbours’ garage is situated between us and their house, and the only window in our garage is facing our house, so noise has never been as big a problem for them as it might’ve been for your neighbours. We certainly never had any comments from them about me working in the garage, and not even about me working outside, when I’d roll my Triton Workcentre out to do some sawing.

    The heat in our ceilingless garage, however, was something else. Opening the small door was like stepping into a car that had been left in the full sun for half a day with the windows closed. It would literally feel like it was trying to push you back when you entered, with the result that I’d leave the window open as wide as possible all summer long, and I’d enter through the small door and rush to open at least one of the large doors as quickly as possible, if not both, since neither of them were motorised and still aren’t. Even with a floor-standing electric fan to try and create some kind of a draft through the open doors,, it was no fun working in there during summer, so I decided to look for something to create some insulation in the simpplest way possible between myself and the tiled roof.

    Initially I in fact considered having a whirlybird installed, but the guy at the one company I contacted to ask for a quote dissuaded me from that idea by saying I should first look at having some kind of ceiling installed, and for that I shall forever be grateful to him. I ended up buying medium-density polystyrene sheets from the Polystyrene Product Company, and after having spent some time figuring out the best way to install them, I did the whole job by myself over a period of five or six days. As I was reaching the half-way mark, I could literally feel the difference in temperature between when I was underneath the already installed part and when not, and nowadays, when it’s about 31 °C in the shade the temperature in the garage is about 26 °C, a degree or so cooler than inside the house, in fact!

    When I was done with the ceiling I had a couple of smaller pieces of polystyrene left over, as well as some extra slightly thinner, but high-density sheets I’d bought at an earlier stage to use as sacrificial surface when using my circular saw, so I started looking at the two large doors, thinking that insulating them might serve two purposes at once because it would not only also help prevent heat coming through the doors, but it might at the same have an effect on the emission of sound through the doors, alleviating the bother, as mild as it might’ve been, of noise from the garage even further. Like you, I downloaded a decibel measuring app onto my phone and took some before and after readings outside the closed while using my thickness planer, the loudest machine I have, I think, inside the garage. The difference in my case was roughly 10 dB.

    I submitted a review with photos of the polystyrene sheets and how well they were serving my purpose in Google Maps under my own name and linked to the Polystyrene Product Company’s local location, so if you’re interested, just do a search for them and you should find it there under Reviews.

    BTW, I don’t think I saw you mentioning anything about a difference in temperature as a result of the insulation you’d used? Were you not having a problem with excessive heat in the garage, even without a ceiling?

    Reply

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