Sound insulation thinking around.

[Yugguy1970]

I hope to keep the Rav for around 7 years, and while I don't expect it to be as refined as a Lexus it can be road noisy.

Basically there's a huge cavern in the rear with nothing more than the trim panels to keep the noise down.

I really noticed that when we had the boot full for the recent trip to Anglesey it cut down the noise.

So I've been researching and sending in enquiries and people like dodomat have recommended two stage processes that might well work but would need like 300 quid's worth of material to do.

The trim pieces are actually fairly easy to remove with a bit of care.

So I am thinking the following:

https://www.dodomat.com/collections/sound-deadening/products/dodo-dead-mat-hex-50-sheets on all the exposed metal, as a base layer and fixer.

Then I have a load of cavity wall insulation in the garage, left over from when we did some work on it.  Why can't I just glue that on top of the dodomat?  Most of it will be hidden under trim panels anyways?

I could save a fortune, as the official car acoustic insulation stuff is horrendously expensive.

[flash22]

Mat will cut panel vibrations, a closed cell foam will dampen/ Absorb sounds

eg.

https://www.silentcoat.co.uk/collections/sound-absorber

A more OE way is to use a felt or recycled foam mat

https://www.woolies-trim.co.uk/p-986-felt

https://www.woolies-trim.co.uk/p-1384-sound-deadening-felt

https://www.woolies-trim.co.uk/c-129-sound-damping

 

[Dippy]

And what tyres do you have? My switch from the Toyota standard issue ?Geolanders to Michelin Pilots hugely dropped interior volume on the motorway. 

[PMW]

Would anyone happen to know if sound-proofing work, whether DIY or professional, affect the vehicle's insurance?

[Nick72]

On 8/22/2023 at 3:11 PM, Yugguy1970 said:

I hope to keep the Rav for around 7 years, and while I don't expect it to be as refined as a Lexus it can be road noisy.

Basically there's a huge cavern in the rear with nothing more than the trim panels to keep the noise down.

I really noticed that when we had the boot full for the recent trip to Anglesey it cut down the noise.

So I've been researching and sending in enquiries and people like dodomat have recommended two stage processes that might well work but would need like 300 quid's worth of material to do.

The trim pieces are actually fairly easy to remove with a bit of care.

So I am thinking the following:

https://www.dodomat.com/collections/sound-deadening/products/dodo-dead-mat-hex-50-sheets on all the exposed metal, as a base layer and fixer.

Then I have a load of cavity wall insulation in the garage, left over from when we did some work on it.  Why can't I just glue that on top of the dodomat?  Most of it will be hidden under trim panels anyways?

I could save a fortune, as the official car acoustic insulation stuff is horrendously expensive.

I find wind noise above about 65mph to be the loudest I've heard of any car I've had... on the PHEV which supposedly supports improved sound insulation measures. Road noise too but not as bad as the wind noise.

[Yugguy1970]

On the back are some Bridgestones which are ok but getting lower.

It was the same with the Design and the Dunlops though.  It's the large area with no sound proofing at all that's the issue I think.

[PCM]

I used stuff from here: https://www.deadening.co.uk/ plus quality all-season tyres plus checking all my door/boot/window seals. 

[TonyHSD]

You will be surprised really if you take one of yours rav4 or any other later Toyota and compare to another car that is quieter. Strip both examples and you will find minimal difference in quantity of sound proofing, but there will be a noticeable difference in materials. Here is where all begins. Adding extra padding here and there will not cure the issue. Might help a bit and give you this more solid feel when you shut the doors but the real micro climate and total environment insulation from outside will not be achieved. Door and windows seals are major factor. Roof lining, metal sheet of bodywork, and suspension set up , all combined together. 

[NASY]

On 8/24/2023 at 11:12 PM, Nick72 said:

I find wind noise above about 65mph to be the loudest I've heard of any car I've had... on the PHEV which supposedly supports improved sound insulation measures. Road noise too but not as bad as the wind noise.

Interestingly I don't get wind noise at speed in what is the same model you have. 

[jackwilliam11]

Your plan seems quite practical! Starting with a base layer of Dodo Dead Mat Hex on the exposed metal sounds like a good approach for reducing road noise in your car. And using the leftover cavity wall insulation on top of the DodoMat could work well, especially if most of it will be hidden under trim panels. It's a creative way to save on costs, considering the high prices of official car acoustic insulation materials. Just ensure that the materials you're using are safe and won't cause any issues down the line. It's great that you're taking steps to make your driving experience quieter and more comfortable without breaking the bank!

[Yugguy1970]

I'm going to have a go at it in the next few weeks and will post some pics on the process.

[Yugguy1970]

The more I look into this, the more I wonder.

What really is the difference between something like this:   https://www.wickes.co.uk/Arbiton-Quick-Fit-Premium-3in1-Acoustic+Thermal-Underlay---8m2-Pack/p/220458

and this:  https://www.dodomat.com/collections/sound-deadening/products/dodo-dead-mat-hex-roll

apart from you get 8 metres worth of the Wickes stuff for a similar price.

[Dippy]

Check fireproofing, but also effects of higher temperatures. Interior of a car parked in summer sunshine, especially if you drive it to France or Spain, can easily hit 45C. Adhesives etc can break down. Stuff designed for houses might not reach such specs. 

[PMW]

32 minutes ago, Dippy said:

Check fireproofing, but also effects of higher temperatures. Interior of a car parked in summer sunshine, especially if you drive it to France or Spain, can easily hit 45C. Adhesives etc can break down. Stuff designed for houses might not reach such specs. 

Good point. Actually the interior temperature of a parked vehicle can go much higher in the summer sun. It can easily reach 60+C after an hour: https://goodcalculators.com/inside-car-temperature-calculator/

[Yugguy1970]

2 hours ago, Dippy said:

Check fireproofing, but also effects of higher temperatures. Interior of a car parked in summer sunshine, especially if you drive it to France or Spain, can easily hit 45C. Adhesives etc can break down. Stuff designed for houses might not reach such specs. 

This is similar to the stuff I have:

https://www.wickes.co.uk/Knauf-Insulation-Earthwool-50mm-Acoustic-Roll---15-6m²/p/143388

It's fire retardant, none-combustible etc.  I'm not worried about it shedding as it will be behind panels etc so won't be touched.  I've got loads so could really stuff the panels and arches.

[Dippy]

Just two points that I thought of. Think I remember a story of someone using chimney flashing instead of branded sound deadening. Great until it melted!