Compare SureWalls
First A Note About STC Ranges - To fully appreciate SureWalls' comparative value to any project, it is first necessary to set the stage for a discussion of STC ratings and ranges. Our research regarding STC performance as it applies to various wall assemblies, we found a considerable lack of consistency in the reporting results of STC performance of various materials in wall assemblies. Some of the older tests of STC wall assemblies, in particular tests dating back to the 1980's and 90's, produced results on the various dampening methods that are difficult to reconcile given what we know today from a whole slew of recent STC testing of those same dampening methods. We do not see the older results as reliable. As a result, we place greatest reliance on the most recent STC testing. In that regard, we have found one particular "go to" resource to be among the best and most comprehensive for reliable and understandable STC data. When we talk of STC performance and STC ranges for various materials or wall assembly types, we generally rely upon the rules of thumb provided by Commercial Acoustics in their handy and reliable STC calculator tool. Taking into account the data they've gathered from a large base of lab and field tests, the algorithms developed for this STC calculator create the most reliable tool we've found to gauge the expected STC performance ranges for various types of materials and installations. It is what we use to develop the cost benefit analyses we share with you on this website. Below is a sampling of the rule of thumb STC values we work from based upon the data provided by Commercial Acoustics.
These are the estimated STC values for some of the most common partition wall assemblies:
STC rating 32 - Wall assembly with 2 X 4 wood studs 16" OC, 1/2" gypsum board each side, no batt insulation.
STC rating 47 - Wall assembly with 25 gauge steel studs, 24" OC, with 5/8" gypsum board each side and 3" fiberglass batt insulation
STC rating 39 - Wall assembly same as above except substitute 2" X 4" wood studs for metal 25 gauge studs
STC rating 51 - Wall assembly same as 2" X 4" wood studs at 24" on center except installed using SureWalls system
STC rating 53 - Wall assembly same as the 25 gauge steel assembly above except installed using SureWalls system
Following are ranges of avg. expected STC gain or loss for various changes in materials or systems:
STC +8 Points - Substituting 25 gauge metal studs for wood 2 X 4 studs
(an interesting observation here is that when we applied the SureWalls system to both 2 X 4 wood and 25 gauge steel stud assemblies, the STC advantage for steel studs over wood dropped from this 8 point margin to a mere 2 point STC margin)
(an interesting observation here is that when we applied the SureWalls system to both 2 X 4 wood and 25 gauge steel stud assemblies, the STC advantage for steel studs over wood dropped from this 8 point margin to a mere 2 point STC margin)
STC +3 Points - Adding 3 1/2" fiberglass batt insulation to a wall vs. none
STC (-)3 Points - Placing studs 16" OC vs. 24" OC (whether wood or metal studs)
STC (-)2 Points - Substituting 1/2" gypsum board each side for 5/8" drywall
STC +5 Points - Adding double layer of 5/8" gypsum board both sides vs. single layer 5/8"
STC +6 Points - Properly installed resilient channel
STC +6 Points - Regular drywall installation with SureWalls system
Common Sense Conclusions About STC and Wall Construction- Our first conclusion is really less a conclusion and more of a baffling question. Knowing this STC data, other than for reasons of extreme focus on penny-pinching, what justification is there for building walls with 1/2" drywall, wood 2 X 4's placed 16" OC and no batt insulation? This wall assembly should achieve an industry worst STC rating of 32. This is the proverbial "paper thin" wall that people loathe. If, for example, this same wall were simply upgraded from 1/2" to 5/8" drywall at negligible cost and installed with the SureWalls system vs. the old-school tape and mud application, the STC value would increase from a paltry 32 to approximately a minimally acceptable 40 STC. The 5/8" drywall would also enable moving to framing 24" OC saving one additional 2 X 4 per drywall panel, thereby more than offsetting the increase in cost from 1/2" to 5/8" while delivering further benefits in sound transmission. In a 2,500 SF home, the difference in cost by going with 25 gauge metal over wood studs (24" OC) would increase the material cost for the walls by a few thousand dollars, but the STC value of the walls would jump substantially to the range of a more premium level 50 STC. That would seem to represent excellent value for the money, value that home buyers would surely notice - not just in terms of being quieter walls, but also in terms of being stronger, less wavy walls. The point is that it's possible, at very reasonable cost, to build walls that will actually delight the people living within them. At minimal added cost, SureWalls can deliver 50+ STC ratings in all common interior walls whether of steel or wood construction. See our cost/benefit analyses.