📞 Call us for a free consultation! 520–392–9486, 8am – 6pm / Log in or Sign up / Contact
logo for room acoustics forum showing a waveform within a circle and the title of the forum
Avatar
Please consider registering
Guest
Search
Forum Scope


Match



Forum Options



Minimum search word length is 3 characters - maximum search word length is 84 characters
Register Lost password?
sp_Feed sp_TopicIcon
How much can a hairline gap between surfaces affect sound control?
Avatar
Member
Members
Forum Posts: 2
Member Since:
April 7, 2017
sp_UserOfflineSmall Offline
1
April 7, 2017 - 4:20 am
sp_Permalink sp_Print sp_EditHistory

I am working through the various pros & cons to reduce outside train sound getting through a window and could use some help.
My current preference is an exterior flush-mount 1/4″ laminated storm window. For water drainage and condensation control, the installation requires sitting the bottom of the window on the sill with no blind stop or caulking. In my case , the storm window would rest on a sloped brick sill.

If a properly installed laminated panel would get me to say an OITC=30, about how much of that value would be lost due to having that small gap without the benefit of a blind stop and caulking? If loss is significant, I would look into either a surface mount storm window that overlaps the rough opening in the brick wall or I would put together an interior window plug/panel. Thanks for any insights

PQ in east TN

Avatar
Member
Members
Forum Posts: 2
Member Since:
April 7, 2017
sp_UserOfflineSmall Offline
2
April 8, 2017 - 5:42 am
sp_Permalink sp_Print sp_EditHistory

I plan on trying an exterior storm even though sound might go under/through the bottom aluminum storm window frame.

If I find flanking after the manufacturer recommended install, I could still put in sound blocking material along the bottom of the storm window frame as long as it can drain. It will be a while until I get back to this effort – please add any tips to help with the laminated storm window install to minimize sound transmission.

I am less inclined to start with an interior storm window since I wouldn’t get a wide air gap between panes. A wide air gap between panes (among other factors) reduces low frequency sound transmission.

Thanks,
PQ

Avatar
Chief Acoustics Engineer
Forum Posts: 387
Member Since:
August 12, 2013
sp_UserOfflineSmall Offline
3
April 8, 2017 - 9:46 am
sp_Permalink sp_Print

Hi PQ, All holes or gaps that can be sealed, must be. Air (sound) is like water. It will find the weakest link and run through it. An STC of 30 is not good. Place another pane of 1/2″ thick safety glass on the noise side of the window. The side closest to noise source.

Avatar
Trenton, NJ
Member
Members
Forum Posts: 1
Member Since:
April 6, 2017
sp_UserOfflineSmall Offline
4
April 12, 2017 - 4:09 am
sp_Permalink sp_Print

I recall seeing an informal sound lab test where a 1/4″ slot was cut along the bottom of a test wall and then retested. The wall went from STC 50 to STC 39.

Avatar
Chief Acoustics Engineer
Forum Posts: 387
Member Since:
August 12, 2013
sp_UserOfflineSmall Offline
5
April 13, 2017 - 12:37 pm
sp_Permalink sp_Print

Hi Steve, Yes, I would believe those numbers.

Forum Timezone: America/Los_Angeles
Most Users Ever Online: 31
Currently Online:
1
Guest(s)
Currently Browsing this Page:
1 Guest(s)
Forum Stats:
Groups: 4
Forums: 10
Topics: 357
Posts: 991

 

Member Stats:
Guest Posters: 23
Members: 14392
Moderators: 0
Admins: 2
Administrators: admin, Dennis Foley
FREE ROOM ANALYSIS
Call Us 520–392–9486
100% Money Back Guarantee