Composite Insulation
Home Up Noise Barriers and Carpet Underlayment Hatch and Engine Box Gaskets Exhaust Silencers Composite Insulation Head and Hull LIners Mounting Systems For Vibration Isolation Sound Absorption Materials Thermal Insulation Vent Duct Silencers Vibration Damping Materials Vibration Isolation Materials




Use: combined sound absorber and barrier for engine spaces. Apply to all surfaces communicating to occupied cabin and deck space. (Generally, thicker composites will give better results than thinner ones.)

Lead Barrier:

Standard: single layer of lead, 1 lb/ft2.

Option 1: "heavy lead", with a single layer of 2 lb/ft2 lead (best for blocking bass and mid-frequency noises, typical of diesels).




- U.L. rated fire retardant foam.

- Available with white "Tough Stuff" urethane or metalized Mylar facing.

This is the most commonly used composite, due to its easy handling and installation characteristics, combined with its good acoustical and fire retardant properties and wear resistance in comparison to competitive products.

Installation: glue in place with back-up mechanical fastening.

Thickness: ", 1", 1", 2", 3".


Quilted Fiberglass/Lead:

- Highly fire resistant fiberglass with quilted oil resistant finish.

This high quality material combines the high resistance to fire and environmental deterioration of fiberglass with a rugged and attractive quilted vinyl/fiberglass cloth vapor barrier finish. It is used in boats of all sizes.

Installation: mechanically fastened, edges taped.

Thickness: 2", 3", 4". (Actual thickness reduced by about 20% due to quilting.



- U.L. rated fiberglass, metalized Mylar or white Tedlar facing.

This composite is used in larger boats which meet higher fire resistance criteria for hull and furnishings, as the fiberglass is highly resistant to fire and chemical attack.

Installation: mechanically fastened, edges taped.

Thickness: 1", 1", 2", 3".


C.G.F.G. with tan Mylar or white Peg Board facing:

- using "Coast Guard Approved" fiberglass.

This composite is made with fiberglass and facing which meet the very strict Coast Guard fire safety requirements 164.009 and 164.012, as specified for large passenger ships. The composite has very high fire resistance.


Installation: mechanically fastened.


Thickness: 2".









Use: barrier for engine spaces (no absorption). To be applied to surfaces communicating to occupied cabin and deck spaces.







- U.L. rated fiberglass.

This material creates a rugged highly fire resistant (lead sheet) interior in an engine box and is used where there is not room for the added absorptive facing of the composites.


Installation: adhesive or mechanical fasteners.


Thickness: ", 1".





- With or without foam - "Carpet Underlayment".

This material is used in the "without foam" composition as a noise barrier curtain, suspended from the deck to the bilge in boats having lined engine boxes above the flush level deck. (This keeps the engine noise away from the uninsulated underside of the deck.) It is also used as a noise wrap for noisy wet exhaust pipes and silencers, such as are often found in "aft cabin" type yachts.

The material with foam backing may be used as a sound barrier on the engine space surfaces in the same manner as the Lead-on-Fiberglass barrier.



Installation: adhesive or mechanical fasteners.


Vinyl weight: , 1, 2 lb/ft2

Thickness: " no foam, " and " foam backing.


Options: fabric reinforced, closed cell foam.






Use: sound absorber with minimal barrier effect. Generally applied to surfaces communicating to non-occupied spaces such as top-sides, lazarette bulkheads, fuel tanks, etc. May be used as complete engine compartment insulation with less effectiveness rather than a lead based composite. Relative features of foam, fiberglass, and Navy Board are similar to those for composites.






Foam (with white "Tough Stuff" urethane or metalized Mylar facing).


Thickness: 1", 2".



Quilted Fiberglass (with vinyl/fiberglass facing).


Thickness: 1", 2". (Actual thickness reduced by about 20% by quilting.)



Fiberglass (with metalized Mylar or white Tedlar facing).


Thickness: 1", 2".



Navy Board (with tan Mylar or white Peg Board facing).


Thickness: 1", 2".











Carpet Underlayment with Foam:


Use: this material is laid on the floor, foam side down, beneath a carpet, on flooring situated over a machinery space, or over the propellers on an aft cabin arrangement. (The combination of acoustic vinyl and underlaying foam creates a barrier effect against noise radiating from the floor.)

Installation: below carpet: sitting free, secured to floor with carpet tape, or glued to carpet. (Special vinyl adhesive required - call Soundown.)

Vinyl weight: , 1, 2 lb/ft2.

Thickness: " and ".

Option: fabric reinforced, closed cell foam.








Perforated Head Liner:


Use: this material absorbs sound within the cabin and provides thermal insulation, as well as a pleasant decorative surface.

Installation: adhesive.


Thickness: ", ", ".








Non-Perforated Hull Liner:


Use: this material provides good condensation control by insulation action of the foam combined with the vapor barrier effect of the leather-like vinyl covering.


Installation: adhesive.


Thickness: ", ", ".








Double Lead: - may be ordered

Heavy Lead (2 lb/ft2): - may be ordered



Density: - 1.8 lb/ft3, +/- 10%

Color: - charcoal gray

Tear resistance: - 1.4 lb/in.

Compression test: - 10% maximum

Thermal conductivity: - .25 BTU - in./hr/ft2/oF

Temperature resistance: - -45oF to 250oF

Sound absorption: - NRC .71 for 1"

Flame resistance: - meets UL-94, HF1



Density: - 1 lb and 2 lb/ft3 (higher densities available)

Color: - black and amber

Thermal conductivity: - .23 BTU - in./hr/ft2/oF

Sound absorption: - NRC .70 for 1"

Flame resistance: - flame spread: 2; smoke devel.: 0; fuel contributed: 15



Density: - 2 lb/ft3 (nominal)

Color: - gray aluminum

Thermal conductivity: - .25 BTU - in./hr/ft2/oF

Temperature resistance: - -20oF to 400oF

Sound absorption: - NRC .70 for 1"

Flame resistance: - flame spread: 5; smoke devel.: 5; fuel contributed: 20

Thickness: - nonimal thickness is based on dimensions prior to quilting procedure




Fiberglass meets USCG 164.009 + MIL-I-742 F type II

Density: - 3 lb/ft3

Thermal conductivity: - .23 BTU - in./hr/ft2/oF

Compressive strength: - 250/ft2

Facings: - white "Peg Board" facing: 164.009 MIL-A-23054

- tan Mylar: 164.009, 164.012 MIL-I-742 F, type I


LEAD (1 lb/ft2):

Thickness: - 1/64"

Density: - 1 lb/ft2 (2 lb/ft2 available)

Flame resistance: - non burning



Color: - aluminum or white

Flame resistance: - low smoke and does not burn readily



Density: - 1 lb/ft2

Flame resistance: - (barrier & foam) meets DOT MVSS 302

Statements that foam plastic materials are "fire retardant" or "self-extinguishing" indicate only that the materials contain fire retardant or self-extinguishing additive, and are not intended to imply or suggest that such plastic foams are "non-burning". Plastic foams are combustible and can be ignited by an open flame. The burning characteristics of foam vary considerably depending on amounts of material present and other combustible conditions. If ignited, plastic foams can burn rapidly and produce dense smoke. Numerical flame numbers are not intended to reflect hazards in plastic foam materials under actual fire conditions.

* Subject to change without notice. Check when ordering.




Acoustic Composite Insulation

Soundown’s Vinyl/Foam composite insulation is an effective treatment for airborne noise that radiates from engine(s), and other machinery. The standard composite consists of two layers of fire retardant foam, sandwiching a mass loaded layer of acoustic vinyl. This composite is designed and manufactured specifically for attenuation of sounds from machinery such as engines, generators, pumps, etc., which have significant base and mid frequency components. Our construction centers the acoustic vinyl between equal thicknesses of foam, front and back. This fabrication optimizes the mid and bass frequency isolation in comparison to other materials having only a thin foam layer on the backside, which are optimized for "tinnier" high frequency noises.

Thickness: 1", 1.25", 1.5", or 2"

Densities: .5, 1, 1.5, or 2
-In units of pounds per square foot. Extra weight for foam thickness must be added.

Thickness: 1", 1.25", 1.5", or 2"

Sheet Size: 4.5’ x 8’ or 4.5’ x 6’ dependant upon thickness and density.
-4.5’ x 8’ For all 1 lb/sft material under 2" thick
-4.5’ x 6’ For all thicker an heavier materials 

Facing: Silver or White Mylar- Rip Stop, Reinforced

Installation: Glue in place and back-up with mechanical fasteners. (The glue and fasteners are available from Soundown.