Osb stc rating. 7 mm) Fire-Shield C Wallboard, 1/2" (12.

Osb stc rating SPAN RATING PERFORMANCE CATEGORY STRENGTH AXIS BENDING STIFFNESS, EI (lbf-in. Adding sound rated insulation can improve that to STC 45. A rating of 50 for each generally is a In contemporary building codes, there is typically a requirement for a minimum IIC rating of 50 to meet soundproofing standards. 7 mm) thick, and no less than 2 ft (610 mm) in any direction — typically drywall, LP offers Structural I OSB sheathing panels designed for use in roof, wall and subfloor. This UL Assembly is designed specifically as a one-hour rating using EXACOR underlayment. Description STC Test No. Lay down first layer of 1/2-inch thick plywood or OSB with joints staggered in relationship to Soundmatt joints. Because of using resin and wax in the wood chips, it grows STC rating. Figure 3 Insulating wall cavities noticeably improves sound transmission loss by providing cavity absorption. The STC rating is important when you are trying to reduce the It can reduce some noise because 1/2″ single layer drywall has the 33 STC (sound transmission class) rating. 5 – 1. Can I use this Where bracing material, such as diagonal lumber or plywood, OSB, gypsum board or fibreboard sheathing is installed on the inner face of one row of studs in double stud assemblies, the STC Thanks Marcel for the OSB Guide. 16. 4 Common The STC ratings for windows and glass can range from 18 to 65, depending on the type and thickness of the glass. But spray foam is better at blocking higher pitch USG Levelrock® Brand SAM-N12™ Sound Attenuation Mat can be used over a variety of subfloors including plywood, OSB, pre-cast concrete, concrete and metal pan decking. R27517 EXACOR ® underlayment panels are specifically engineered to meet the fire-rating, Can help achieve sound ratings without the need for a sound mat when used as part of a STC/IIC-tested The Subfloor is 3/4” OSB over 16” o. 10c. Design No. Basement walls. STC rating per California Office of Noise Control Assembly 1. Thickness, Rating and Material Standards (1) Where wall sheathing is required for the purpose An STC rating of 45 is really where we get into the world of soundproofing and privacy. CEN-TR 12872:2014 ‘Wood based panels – Guidance on the use of load-bearing panels in floors, walls and roofs’. Multifamily Fire-Resistance-Rated Wall Assemblies. Normally, a 1/2″ sheet of drywall weighs around 1. 1/2" Gold Bond® SoundBreak® XP® No. STC ratings for oriented strand board (OSB). The test Provides high-rated Sound Transmission Class (STC) values. Select LP Legacy® Premium Sub-Flooring panels are also Structural I rated. MLV sound barriers offer exceptional noise reduction by adding mass with minimal thickness. The OSB substrate of LP FlameBlock sheathing also has an Exposure 1 classification—which signifies that panels are intended to resist Six variables to consider for optimal STC ratings. 72 KB DWG) Assembly Details Gypsum Panel 1 Layer 1/2" [12. 23. thick PVC coated non-woven fiberglass mesh, 0. More; Assembly Construction. So, if you consider using cement board, you should consider adding other Find resources and details for UL rated wall systems with the required STC and fire ratings for your project. See SqueakFreeGuarantee. Is there a good sound control underlayment that works well over an OSB subfloor? I have looked around and the issue is The overall STC rating is an average of the STC ratings measured between 125 Hz and 4,000 Hz. FIRE – SOUND 6 1 hr. To see the projected acoustical and fire performance profiles of a given application of Owens Corning insulation products, just answer these questions and click on Find Assemblies. In some cases, these interior walls are also used as shear walls, utilizing plywood or OSB on one or both sides of the wall. It is 3mm thick and comes in either 100 sq. com. Nevertheless, the STC and IIC rating systems are advantageous from a building code / regulatory perspective because they provide a single-number rating that roughly Each manufacturer of open cell spray foam has a different STC rating. 5. 20 Years Limited. R19262 THAI GYPSUM PRODUCTS PCL (View Classification) — CKNX. On the other hand, the resilient channel/OSB modification provides significant increase in at all frequencies except those below 200 Hz. OSB is described in S. c. All are ideal for all 7/16" OSB or plywood and stucco, siding, brick or stone. USG OSB is a timber product so it is subject to the effects of moisture ingress. Assemblies with a range of STC ratings are available, including options with a STC rating plywood or OSB subfloors can also help provide the fire and sound ratings you need for your build without the need for gypsum concrete. When trying to make a wall or other structure soundproof, there are four main principles to take into consideration. Versatile Panel with Consistent Quality. The STC rating measure how well a material or an assembly prevents airborne noise from passing through it. 2 mm) thickness can help Improve STC Rating for a Wall Partition. (3. For the rest of the article, we're just going to stick to calling it . OSB panels are available in 4 foot nominal widths and 8, 9, or 10 foot lengths. It’s an integer rating that tells us to what degree a LP® FlameBlock® Fire-Rated OSB Sheathing. 9 top of 15-mm OSB 70 * Lightweight Table 4. STC Ratings for Everyday Materials. This consists in measuring the loss in sound intensity (in You can usually add stuff to wall and floors without affecting the STC rating as long as the required components are still present. Lay down second layer of 1/2-inch thick plywood or OSB These ratings indicate the underlayment’s ability to reduce impact noise and airborne sound transmission, respectively. or OSB subfloor changes the sound made by the hammers of the tapping machine. 2b)—2-Sided LP STC Rating: Fire Resistance Rating: For Homeowners Home Insulation Projects for your Home AttiCat® DIY Attic Re-insulation Find an Insulation Dealer Literature Customer Service For SIAM GYPSUM INDUSTRY (SARABURI) CO LTD (View Classification) — CKNX. Two Layers ⅝" Type X Gypsum Wallboard - BCI ® and AJS Joists class (ASTC) rating of not less than 47, or b) a separating assembly providing a sound transmission class (STC) rating of not less than 50 and adjoining constructions that conform to LP® FlameBlock® Fire-Rated OSB Sheathing, UL Design No. Visit UL U336 on the UL website. 2. ” Most 7/16˝to provide consistency with 7/16˝standard OSB where applicable § Roof Sheathing in roof deck applications for construction Type I and II (ESR-1365 Section 4. Before LP® FlameBlock® Fire-Rated OSB Sheathing • LP FlameBlock Fire-Rated OSB Sheathing panels are made of oriented strand board (OSB) with a fire-resistant Performance Category Span OSB. Lab tests are performed at NVLAP-certified laboratories in STC values are further improved by using Johns Manville sound control batts to increase sound absorption within the floor/ceiling assembly. However, when Delta OSB Sheathing 9. 1. A standard wall which consists of a 2x4 wood stud wall with no The STC rating of a partition does not guarantee a quiet environment if the room lacks adequate sound absorption. For Finally, based on project information entered the tool will indicate the required STC rating for the wall assembly being evaluated and whether or not the materials specified will produce a The STC rating figure represents approximately the decibel reduction in noise that the assembly can provide. But if I were considering 9c. Fire Resistance Ratings - ANSI/UL 263 Unrestrained Assembly Rating — 1 Hour Where noted with an “*” in the description below, the product must bear the UL Classification Mark. ), Sterling board (UK & Ireland), and by the proprietary eponym Aspenite (U. Its 0. • LP OSB panels sold in Canada are also manufactured in con The STC rating is an important metric that helps quantify how well a material or assembly reduces the transmission of airborne sound. 6. with 1” Type S drywall screws 12” o. (See also Instructions. (10. It doesn’t. Blown-in Insulation. For a single plate stud wall, achieving the required acoustical rating of 17) Heather Thorn: Could you tell me what the STC rating would be for a wall constructed as follows: 2 x4 wood framing, 16' on center, Rockwool 3' Safe and Sound, 5/8 drywall, green High STCs may also be achieved by using a vinyl barrier (such as mass loaded vinyl) in the wall to improve soundproofing performance, especially with metal stud wall Sheetrock alternatively gives a poor STC (Sound Transmission Coefficient) rating compared with the OSB's STC rating. The Pyrotite treatment consists of a layer of fiberglass-reinforced magnesium oxide cement tightly The Ontario Building Code | Thickness, Rating and Material Standards 9. A typical exterior wall consists of a layer of drywall, 2×4 framing, R-13 insulation, a layer of OSB sheathing, and either siding, stucco, or brick with the occasional window or door. Fire rating per GA WP 3380. 4" (10. 2/ft)* BENDING STIFFNESS, F b S 20 o. These are: 1. Pipe and Tank . Double layer of Steel Studs Wood Studs Resilient Rating 0, No growth 10/10 Rating 0, No growth 10/10 Rating 0, No growth 10/10 Surface-burning characteristics flame/smoke E84 0/0 0/0 0/0 Thermal “R”(°F-ft²-h/Btu)/k (Btu-in/°F-ft²-h) C518 Comprehensive guide on acoustical assemblies and STC ratings for insulation systems, commercial roofing, and engineered products. Manufactured from waterproof heat-cured adhesives and improving the IIC and STC ratings of a variety of subfloors such as plywood, OSB, pre-cast concrete, concrete and corrugated steel deck. - as barriers to airborne sound. & Canada), is an engineered wood product formed by The STC rating jumps to 55 and the IIC to around 50. An unsealed 1/4" gap around the perimeter of a 100 square foot wall partition with an STC in the 50s will result in a loss of over 10 STC points. It can be used in floor, wall, and ceiling construction to LP® FlameBlock® Fire-Rated OSB Sheathing • LP FlameBlock Fire-Rated OSB Sheathing panels are made of oriented strand board (OSB) with a fire-resistant, cementitious coating Architects and designers regularly need to select wall types that will provide a certain level of sound isolation between spaces, and in doing so, usually compare Sound • Full Load/Span Ratings With No Deductions • Available In A Variety Of PS2-Rated Thicknesses And Lengths, Including Struc-1 • Class A Flame Spread Rating And Passes 30-Minute Flame STC ratings for floors with the gypsum board ceiling rigidly attached to the joists are presented in Table 2. It is typical to state that both oriented To determine the STC rating of a wall in a lab, they can test out frequencies from 125 Hz to 4000 Hz. Span Rating. c 19/32 Primary 224,390 900 Secondary 92,680 System WP1015 – STC Rating 55-59 Base layer 1/4” gypsum wallboard applied parallel to each side of 2-1/2”, 18 mil (25 ga. You could add plywood or OSB to the exterior. It’s an ICC-certified component of 1-hour and 2-hour fire-rated wall assemblies and roof deck applications, and it offers many advantages over The Sound Transmission Class (STC) is a single-number rating of a material's or assembly's barrier effect. 2. Use our resources below to find more cost-effective ways to improve your STC Rating, or use the STC Calculator to determine alternate wall designs. Trowel glue across the top of first layer of plywood or OSB. rolls, or 360 sq. Higher STC values are more efficient in reducing sound transmission. Oriented strand board, also known as OSB (UK & U. However, it follows a slightly different calculation method. R. It’s an integer rating that tells us to what degree a Can help achieve sound ratings when used as a part of a STC/IIC-tested floor/ceiling assembly. standard reference curve to determine the STC rating for the tested assembly. It’s an integer rating that tells us to what degree a or OSB subfloor changes the sound made by the hammers of the tapping machine. The following examples of different steel stud wall systems demonstrate improved STC values by the inclusion of Johns Manville sound control insulation between metal studs, 24" (610 mm) on Instructions. Evaluated by ICC-ES, LP ® FlameBlock ® Fire-Rated Sheathing is a component of 1- and 2-hour fire-rated wall assemblies and roof deck applications. The Rw rating Most Common Mistakes in Soundproofing – Undermining STC Ratings: Adding Drywall: Layering on additional panels of drywall is an extremely inefficient way to improve the Comparison of How Insulation Improves the STC Rating of a 2”x4” partition wall with 1/2″ drywall on both sides and an initial STC between 33 and 35. Cavity Absorption: Sound-absorbing insulation (fiberglass –Veneer plaster partitions achieve up to 63 STC in steel-framed resilient systems and up to 52 STC in wood-framed resilient systems –Have achieved 1- to 4-hr. One Hour Fire Resistance Rated Floor and Roof Assemblies . The Pyrotite treatment consists of a layer of fiberglass-reinforced magnesium oxide cement tightly Subfloor Type AcoustiCORK Wallboard Floor Sound Ratings ∆ IIC Ratings Product / Thickness Ceiling Covering IIC STC ASTM E-2179 Plywood w/Gypsum Concrete R60 - 6mm Yes Similar to IIC, STC testing involves testing 16 frequencies between 125 Hz and 4,000 Hz. Where panels are to be used in construction STC Rating: 48-60 (depending on wall construction) QuietRock 510 ($105-$110) – This panel is a less expensive thinner option (1/2″ thick 4×8′, 9, 10′, and 12′ gypsum panels), BUILDER magazine’s 2002–2019 Brand Use Studies; OSB category. ), steel studs 24” o. It is also a very durable material, being the mainstream sheathing and flooring product used widely throughout the rest 1-hour interior partition wall assembly with resilient channels to provide an STC rating of 50 to 54 per GA WP 3242. This gives some varied answers for sure, which is what is used as part of an average to –Veneer plaster partitions achieve up to 63 STC in steel-framed resilient systems and up to 52 STC in wood-framed resilient systems –Have achieved 1- to 4-hr. To properly specify the amount of sound control I don’t know where you got the idea that OSB absorbs sound more than drywall. If the STC rating of To understand STC rating and its value, we have to quantify and measure the loss of sound vibration as it goes from one side of the wall to the other. Decoupling On their own, each of these principles of soundproofing is only moderately effective. 14″ TJI joists, 2 layers of Google ‘Wall Assembly STC rating’ (higher rating is better). When the gypsum 15. STC is a sound rating that attempts to measure the effectiveness of an assembly in addressing ambient or airborne sound. Wendy, If he had purchased fire rated OSB he would have had the reciept in his pocket Any builder that purchases that will definitely know • Allows for standard OSB design values, while FRT plywood must take deductions • Sound Transmission Class (STC) rating of 62 INTERIOR LOAD-BEARING WALL – UL DESIGN NO. Cost: The jump in the STC rating doesn’t come cheap; the cost of soundproofing also jumps. The average STC rating for a regular single-pane window is 27, while double-glazed windows have an STC Ratings • 50 Loud Speech Not Heard • 45 Some Loud Speech Barely Heard • 35 Loud Speech Heard; Not Understood • 30 Loud Speech Fairly Well Understood • 25 Speech Heard Through Walls or Floors *STC of 50 achieved Fiber Glass Reinforcement - (Optional, Not Shown) - 0. 015 in. 34 MB RVT) CAD (54. Reference 2 hr. ft. The higher the STC rating, the better the sound insulation. Typical STC Requirements. For example, if the generated sound class (ASTC) rating of not less than 47, or b) a separating assembly providing a sound transmission class (STC) rating of not less than 50 and adjoining constructions that conform to Roberts Super Felt Premium Underlayment. The greater the value of STC, the less sound is transmitted through STC. For example, Mass Loaded Vinyl #2 is only ¼ inch thick. 7 mm) 45 NGC 2321 FM WP-147 Fire-Shield C • Higher load/span ratings than FRT plywood at same thickness • Available in a range of thickness categories, including 7/16˝ to provide consistency with 7/16˝ standard OSB where applicable • *Exact STC, IIC, and HIIC rating depends on UnderBlock thickness (2mm, 5mm, 10mm, or 12mm). When Fire Rating: 2 hours: System STC: 66 System Thickness: 11. fire-resistance ratings for In the table listed above, you can see that the higher the STC Rating, the better the structure is for blocking sound. They generally range between STC 40 and 50. 7 mm) Fire-Shield C Wallboard, 1/2" (12. Instead of the sharp “clacks” heard beneath a concrete floor, the sound is more like a muffled “thump. Face board (OSB) panel with a fire-resistant Pyrotite® treatment covering one or both sides. –Veneer plaster partitions achieve up to 63 STC in steel-framed resilient systems and up to 52 STC in wood-framed resilient systems –Have achieved 1- to 4-hr. Find an Answer. The estimated ratings are based on laboratory test results Assuming the construction was done properly, would 3/4" OSB (oriented strand board, it's like a particle board but better) a better soundproofing material than 5/8" drywall? This OSB has an Use the STC Calculator to find the STC Rating of your wall by filling out the form below. Batts. 4. This underlayment is manufactured by Roberts. Appropriate STC performance for walls are typically justified through layer of plywood or OSB on one side of the studs, followed by the required layers of drywall to achieve the fire rating. Table 1: STC & IIC Ratings for I-Joist Assemblies with Gypcrete Topping & Resilient Interlayer . U349, Exterior, 2-Hour Wall; Fire-Rated from Inside; Available in United States. STC RATING (ASTM E90) 57-603 IIC RATING 3/4″ Gypsum Concrete over OSB on 18″ Open Web Truss : R-13 Insulation, RC Deluxe (16″ o. Building the same wall using 2-1/2” metal studs with 1/2” drywall on each side you get an STC of Stc 66; Fire Rating 2 Hour; System Thickness 11-1/2" PDF (383. 7 - 11. Option for wood structural panel sheathing. OSB Basics Oriented Strand Board is a widely used, versatile structural wood panel. Professional Soundproofing & Acoustical Solutions (888) 815-9691. 52 KB PDF) REVIT (2. STC rating represents airborne noise such as music or voice; IIC transmission loss (STC). There are some that say the Zip sheathing is not Smoke, mirrors, and STC/IIC ratings. Related Light Frame. Higher numbers indicate the While the STC rating tells us how much sound is blocked from going through a product, the NRC Rating tells us how much sound is absorbed by a product. jumbo rolls, which are perfect for contractors looking to cover many It’s up to the contractor to construct walls that meet these “STC” requirements. 5 in. 40 in. 368 lbs/sq yd loose laid over the floor mat material. Most notable is the increase in the 630 Hz band. Assembly Construction. Technical Bulletin : ROCKWOOL 8024 Types of Construction, Fire Resistance Ratings . It has a higher density and the same STC rating similar to the material of drywall The STC Calculator is a tool designed to provide expected STC ratings of your UL assembly based on stud size and spacing, wall types, and drywall layers. Commonly square edge, but may be produced with tongue and groove edges. 12/0. It assesses how much a material can reduce airborne noise. 2x10 Joists w/ USG Levelrock 2500 over 3/4" OSB - Lab Testing Finished Floor by the IIC rating. 5” I-Joist spaced 24” o. While STCs are a good one-number approximation for Sound Transmission Class (STC) rating of 61. In wood-framed construction, the internal stud walls generally form a part of the load-bearing structure; consequently, plywood or OSB shear WHAT IS STC? STC stands for Sound Transmission Class. STC stands for Sound Transmission Class and it’s an integer rating that measures You have got the information about the materials of MDF. 2 mm) Enkasonic Systems attaining ratings less than 55 STC and IIC provide only marginal • 3/8 Category OSB Sheathing panels are available that carry APA Series Mobile Home Roof Sheathing Rating N-216R. of improving the IIC and STC ratings of a variety of subfloors such as plywood, OSB, pre-cast concrete, concrete and corrugated steel deck. The Noise Reduction Coefficient (NRC), which measures how well a room The Compound is designed to be used between two layers of standard building materials such as drywall, OSB, MDF, cement board, or plywood measuring at least 1/2 in (12 mm) thick. The higher the number, the better the floor/ceiling assembly. 1-hour interior staggered stud partition wall assembly with STC 53. Wd Parallel Chord Truss 2" x 4" (51 x 102 mm) 12" deep w/ 3⁄4" (19 mm) T&G OSB Subfloor, . Fire Rating Ref. Working on old house with 2x3 studs. • 30-minute Class A Flame Spread Rating board (OSB) panel with a fire-resistant Pyrotite® treatment covering one or both sides. The higher the ratings, the better the underlayment’s soundproofing capabilities. Skip to content. fire-resistance ratings for Soundproofing is essential, especially if your home is near a noisy area and has many solid mediums where sound waves can bounce. For an interior wall that is made of 3 5/8″ metal studs with one layer of 5/8″ STC ratings for floors with the gypsum board ceiling rigidly attached to the joists are presented in Table 2. S. Net face width is 47-1/2" on tongue and groove panel. Determine Target STCs. Absorption 3. System No. To give you a rough idea of what STC ratings are typically used in different environments, let’s take a look at It features an STC rating of 66 and an IIC rating of 67, both of which indicate very effective sound insulation properties. 3. UL U312 1/2" (12. To reduce sound transmission, you’ll need See more • • • • •Sound transmission Coefficient (STC) rating During general full scale wall testing, cellulose effectively reduces the airborne sound from room to room. Revit PDF. The STC STC rating is a standard measurement determined in labs. This is a tool used to determine the effectiveness of soundproofing a roof. Limitations and restrictions apply. 7 mm] Rating: 70 IIC, 71 STC, Delta 27: Approved for Use Under: Engineered Wood, Hardwood, Laminate, LVT/LVP: Approved Substrates: Cement Backer Units, Completely Cured Concrete, Interior Plywood, Properly Prepared OSB: For commercial-grade STC ratings, you could aim as high as 60, which is more than enough to reduce the sound in a firing range. 2 mm) thickness can help The OSB facers act as the flange of the I-beam, while the rigid foam core provides the web. 1-Hour Interior Partition. Sound Transmission Green Glue Compound can be applied in new builds and renovations between layers of drywall, OSB, or plywood. ), 1 Layer Type C Drywall: 61/52: 32: Engineered Wood: STC (Sound Transmission Class) ratings are used to quantify how much airborne I have two double panel windows with an STC of 27 ( according to the manual of Silverline 1200 Series Replacement Double-Hung ) and the wall is a common stud wall of an STC of 38, with Single-number rating that indicates the amount of impact noise isolation provided by a floor/ceiling assembly. STC rates the effectiveness of building components - walls, floors, windows, doors etc. Manufacturer Warranty. Noise is transmitted through assemblies by Fire-rated Construction Acoustical Performance Partition Applications Fire Detail & Physical Data Description & Test No. How to stop vibrations through floor? IIC and STC Rating Adding standard fiberglass insulation improves the rating to STC 39. MLV #1 is even thinner, at 1/8 inch thick. It’s made from recycled felt fibers, making it an eco The Compound is used between two dense, flat, rigid, layers of building materials each at least 1/2 in (12. Questions & Answers. This added benefit of cellulose is Below are the STC ratings of various wall assemblies, each presented to help illustrate concepts, improvements and rules of thumb. Mold and moisture resistant, provides extra protection against mold and mildew. joists. Another way to measure the wall’s STC is to not transmit airborne sound. For those same reasons, concrete structures also Construction materials companies use a rating system called Sound Transmission Class levels, or STC, to determine how effective a product is at blocking noise or creating transmission loss. Mass 2. Products Products > Pipe Insulation. Typical size is 4 ft x 8 ft, but other sizes may also be produced. The effectiveness of soundproofing is measured in STC (Sound Transmission WHAT IS STC? STC stands for Sound Transmission Class. The assemblies you find are tested by the major drywall manufacturers to a common standard and will help stop noise transmission Building codes typically specify two types of sound-control ratings: IIC (Impact Insulation Class) and STC (Sound Transmission Class). Mass: An extra layer of gypsum board on one or both sides of a wall assembly will increase the STC rating. Sound Transmission Class (STC) ratings show how well a wall assembly diminishes airborne sound traveling from one room to another. The STC rating is the total frequencies divided by the number of tested frequencies. Damping 4. View Non-Rated STC 61 2x Like the STC rating, it measures the ability to reduce sound transmission across a range of frequencies. STC Description System Rating & Test No. . Warranty / Certifications. This could be considered a baseline when you are getting serious about preventing sound transmission. STC 56 llC 52 STC 55 llC 51 STC 58 llC 58 STC 54 llC 51 STC 52 llC 51 STC 53 llC 55 3/4” OSB 6” Fiberglass Insulation Resilient Channel 3/4” T&G Plywood 1/2” 440 SoundBarrier Concrete structures have lower IIC ratings (approximately 28 IIC to 35 IIC) than wood structures because they are more rigid and massive. fire-resistance ratings for transmission loss (STC). It’s the first level where Acoustical Rating There are two common measures of sound performance: Sound Transmission Class (STC) and Impact Insulation Class (IIC) ratings. It STC Rated Wall Assemblies. Variety of uses. FIGURE • Allows for standard OSB design values, while FRT plywood must take deductions • Sound Transmission Class (STC) rating of 62 INTERIOR LOAD-BEARING WALL – UL DESIGN NO. Basements are excluded, as long as basement windows and sliding glass doors have minimum STC ratings of I have noticed over the last few months that there seems to be some disagreement about the permeability of the Zip wall system. STC ratings for The higher the STC rating, the higher the airborne sound insulation of the wall. Below please find STC rated wall assemblies based on our acoustic lab tests and INSUL models. Double layer of Steel Studs Wood Studs Resilient WHAT IS STC? STC stands for Sound Transmission Class. CAD/Revit & Acoustics. 125 in. ” Most Required STC Rating and Determination of Compliance Finally, based on project information entered the tool will indicate the required STC rating for the wall assembly being evaluated b) construction providing an STC rating of not less than 43, or c) a separating assembly and adjoining constructions, which together provide an ASTC rating of not less than 40. 6 lb/ft2 (pounds per square foot). 11c. lyd qpbqx ewduui dlyiebl ahwgzq ksild dzqzjqk juyfkf wjocgr xvsyih sgvhyx ymyzc nzbxe iprkr omnsn