How to Soundproof Engine Housing or Engine Cover in Boats

Soundproof engine housing or cover
Many pleasure crafts have an onboard engine housing or engine cover that is part of the deck of the boat, mostly sloops and smaller pleasure crafts. The engine housing, or cover, is usually made of fairly light materials such as plywood or polyester. These light materials are the main reason for noise problems on those crafts. We have the solution and products to solve this issue and make your boat ride more pleasurable. An important thing to keep in mind: make sure to use a product with sufficient heat resistance!

How to soundproof an engine housing or engine cover
To insulate engine noise you need to install an acoustic noise absorbent product in the engine housing or cover, as thick as possible. Make sure that the whole engine housing or engine cover is insulated, do not skip parts, this will result in noise leaks! Products cannot touch parts of the engine. The picture on this page shows an excellent example of an engine cover insulated with Merfocell PU and taped of seams.

Products to insulate the engine housing or cover
When you have less than 10 cm between the engine and a product we speak of high temperatures. These products are the ones we recommend:

Merfocell FC
Max. 110 °C. Fibreglass cloth top layer.
Flamex FC
Max. 150 °C. Fibreglass cloth top layer, for flat surfaces only.

If the engine room or engine compartment is larger, with at least 12 cm or more distance between the engine and the absorption material, we can assume that temperatures are medium and not higher than about 60 to 70 °C. It is your responsibility to make sure if this is true. These products are the ones we recommend:

Acousticcell PU
Max. ± 80 °C, PU protective top layer oil- and moisture proof.
Merfocell PU (as shown in the image)
Max. ± 80 °C. PU protective top layer oil- and moisture proof.
Flamex PU
Max. ± 100 °C. PU protective top layer oil- and moisture proof.

How to soundproof engine housing or cover
To reduce low engine noise even more, from big diesel engine noise for example, means to isolate the engine. This is done by making the engine housing or cover as heavy as possible. Only with mass you can soundproof the lowest frequencies. You can achieve this by applying heavy Isomat TS sheets on the engine housing or engine cover and then apply an sound absorber as described in the paragraph above. These are the recommended products:

Isomat TS
Max. ± 80 °C, Mass load vinyl to increase mass and soundproofing
Merfocom
Max ± 100 °C, Soundproofing and absorption.

Products for soundproofing an engine housing and engine cover

Soundproofing engine housing or cover