Thermal insulation under carpet recommendations

[WCBlueSky]

I get uncomfortably high temperatures in the passenger foot well. I pulled out all the carpet and am planning to replace the jute backing with new 40oz jute. What else do you recommend for insulation? I care much more about reducing heat than noise.

In other threads I've seen people mention Heatwave Pro, Thermozite, and Reflectix. Any real-world experience?

Also, anyone used secondary heat shields or insulation on the cats or transmission tunnel (outside on the body)?

 

[LandCruisinMy93]

thermozite seems to work alright. I never took before and after temps but it is somewhat cooler in the cab.

 

[mudgudgeon]

I used ¼" medium density closed cell EVA foam with a foil backing on top of dynamat, then underlay.
It made a huge difference to heat and noise.

Layers that trap air are what you want.

The product I used was made as thermal insulation used in construction to insulate inside metal wall cladding, or metal roofing to prevent condensation forming on metal.

Cut to shape as neatly as possible, and tape every joint and seam with foil tape.
Take care to create a complete a layer as possible, and as far up the firewall a possible. Also, pay affection to getting a sealed layer around the shifter in the trans tunnel. Sealing around this fully made a huge difference in mine.

Look for ACL heatshield or similar for use as secondary exhaust heat shields under the floor.

This stuff can be cut with tinsnips/ aviation snips and can be bent and moulded to compound shapes. Rivet or screw or use stainless steel zip ties to secure it.
Again, it traps air to provide the primary heat barrier, and foil to reflect heat

 

[Azca]

Heat shields, foam insulation have proven to help. I have also heard good reviews on the use of lizardskin for this. I am still working on insulating mine for heat and noise and if I could do it all over again, I would use lizardskin instead of the mat sound insulation and foam sheets over the top of it.

 

[brettk]

Layer 1

Amazon product ASIN B07BLSP8JV
Layer 2

Amazon product ASIN B07LH1X7QX
Not exactly what you’re asking for, but I didn’t go with back with jute. A lot cheaper than Dynamat too. I’ve had it in both of my vehicles for 2 years now, and it works great. Doesn’t hold musty smells either.

 

[tmxmotorsports]

Layer 1

Amazon product ASIN B07BLSP8JV
Layer 2

Amazon product ASIN B07LH1X7QX
Not exactly what you’re asking for, but I didn’t go with back with jute. A lot cheaper than Dynamat too. I’ve had it in both of my vehicles for 2 years now, and it works great. Doesn’t hold musty smells either.

Coming back to this soon for a build

 

[katravan]

Doesn’t hold musty smells either.

Are Dynamat or any other popular solution known to do this? Planning to tackle this early next year but never considered smell as a potential issue.

 

[mudgudgeon]

Layer 1

Amazon product ASIN B07BLSP8JV
Layer 2

Amazon product ASIN B07LH1X7QX
Not exactly what you’re asking for, but I didn’t go with back with jute. A lot cheaper than Dynamat too. I’ve had it in both of my vehicles for 2 years now, and it works great. Doesn’t hold musty smells either.

Hmmm, can't see Amazon links for some reason

 

[Mjones]

I get uncomfortably high temperatures in the passenger foot well. I pulled out all the carpet and am planning to replace the jute backing with new 40oz jute. What else do you recommend for insulation? I care much more about reducing heat than noise.

In other threads I've seen people mention Heatwave Pro, Thermozite, and Reflectix. Any real-world experience?

Also, anyone used secondary heat shields or insulation on the cats or transmission tunnel (outside on the body)?

I did mine for sound proofing but have been please with insulation effects:
I followed the rec's from Sound Deadener Showdown (no longer in business), archived here if interested.
Sound Deadener Showdown | Your Vehicle Quiet - https://web.archive.org/web/20210609214849/https://www.sounddeadenershowdown.com/

Quick summary:
1. CDl tiles - this is for sound deadening so could skip it. The stock already has some of this but adding more helps.

2. layer of Mass loaded Vinyl - get one known to not smell like from here
soundsulate 1lb Mass Loaded Vinyl 4' x 25', 100 sf roll, Soundproofing, MLV 739027503552 | eBay - https://www.ebay.com/itm/Soundsulate-1lb-Mass-Loaded-Vinyl-4-x-25-100-sf-roll-Soundproofing-MLV-/121596772331
You could probably go with thinner than 1/8 - you use HH-66 Vinyl Contact Cement to glue it all together
www.amazon.com/gp/product/B00BUB5JOA/ref=ppx_yo_dt_b_search_asin_image?ie=UTF8&psc=1

3. MLV needs a decoupler- so use this or equivalent Second Skin Mega Zorbe Melamine Foam Sheet
www.amazon.com/MegaZorbe-Hydrophobic-Melamine-Foam-Stick/dp/B01N2497HN?th=1
If you were to skip a step it would be this one but if you go to the effort of MLV this is easy.

4. cover the MLV with this 'undercarpet' (Design Engineering 050113 Under Carpet Lite Sound Absorption and Insulation). This would in place of the jute. I bought a new OEM carpet set and left the stock jute on it.
www.amazon.com/Design-Engineering-050113-Absorption-Insulation/dp/B008NF84J8/?_encoding=UTF8&pd_rd_w=FHw1J&pf_rd_p=09c27161-2df3-4bce-95e3-5a30d05d01d6&pf_rd_r=F3TVEV3N269BGSCQJ39A&pd_rd_r=dc9e7396-1067-4b19-909a-082c46ac4e4f&pd_rd_wg=7G68Y&ref_=pd_gw_ci_mcx_mr_hp_atf_m
then carpet over .This step is not in the Sound Deadener Showdown list. My son did this to his truck as an extra layer and I was pleased with the cost/effort benefit. I went back and added it where I could. It gets thick so it can't happen everywhere (i.e. under the gas pedal) and under certain trim areas.

5. for ceiling - either use the 'undercarpet' if you can get that to adhere between roof underside and put the headliner back on. I used a foam similar to this
Neoprene High Quality Foam Sheets - https://www.foambymail.com/NE-HQ/neoprene-high-quality-foam-sheets.html
for sound but it has insulation properties. The foam was good enough and easy to install with a glue gun.

It's a chunk of work - all of this for the entire vehicle, but I was doing a full stereo rewire, backup camera, etc and fixed a bunch of little things here and there (bulbs and broken plastic things) - it made it really easy to do all this while it was gutted. And cleaned everything.

edit: For just the passenger footwell this wouldn't be that hard of a job and just order enough of what you'd need. There's probably a smaller about of MLV somewhere on-line. The passenger side was easy to make it thick with this triple layer of stuff.

 

[Spdstr280Z]

I don't have any real world data yet, but I did Lizard Skin CI (over SC for noise) and a layer of DEI Boom Mat Under Carpet instead of jute. I used the jute that came with the ACC carpet kit behind the second row seats, and I'm second guessing that now. I did a few tests playing around with a heat gun and torch, and the results seem good.

Design Engineering DEI 050100 Boom Mat Under Carpet Insulation | Summit Racing - https://www.summitracing.com/parts/dei-050100

Edit - MJones posted while I was typing, reminded me to mention that the Boom Mat is a layer of mass loaded vinyl with an adhered layer of acoustical foam as the decoupler as he mentioned. If you go DEI, DO NOT waste your money on the spray adhesive. May be good, but the cans / nozzles are garbage. 3M 77 or 90 is readily available and works great.

Jason

 

[alia176]

I don't have any real world data yet, but I did Lizard Skin CI (over SC for noise) and a layer of DEI Boom Mat Under Carpet instead of jute. I used the jute that came with the ACC carpet kit behind the second row seats, and I'm second guessing that now. I did a few tests playing around with a heat gun and torch, and the results seem good.

Design Engineering DEI 050100 Boom Mat Under Carpet Insulation | Summit Racing - https://www.summitracing.com/parts/dei-050100

Edit - MJones posted while I was typing, reminded me to mention that the Boom Mat is a layer of mass loaded vinyl with an adhered layer of acoustical foam as the decoupler as he mentioned. If you go DEI, DO NOT waste your money on the spray adhesive. May be good, but the cans / nozzles are garbage. 3M 77 or 90 is readily available and works great.

Jason

Jason,

Did I read that correctly, 3/4" thick?

 

[Spdstr280Z]

Jason,

Did I read that correctly, 3/4" thick?

Hmmm, maybe a typo ? It's 3/8, inch, ~9.5 mm. It's actually thinner than the uncompressed jute from the ACC carpet kit.

Jason

 

[alia176]

I bet I read it wrong, thx.

 

[baldilocks]

This company also sells a product that is reflective on both sides. I used that to reinforce heat rejection between the existing exhaust system heat shields and the lower surface of the floor boards. This project was my second attempt at improving interior floor board temps and it really worked well. I think the big deference was adding the heat reflective material to the underside.

 

[Wrencher93]

This company also sells a product that is reflective on both sides. I used that to reinforce heat rejection between the existing exhaust system heat shields and the lower surface of the floor boards. This project was my second attempt at improving interior floor board temos and it really worked well. I think the big deference was adding the heat reflective material to the underside. View attachment 2824141View attachment 2824143View attachment 2824142View attachment 2824144View attachment 2824145

You had any issues with dirt and grime causing that product to come off? I would imagine that stuff would have a hard time staying put when subjected to wet and dirty environments. Just curious.

 

[alia176]

This is great info Baldilocks, thanks for sharing the pics. They really helped driving the point home. Looks like you used some type of black glue for adhesion.

 

[baldilocks]

You had any issues with dirt and grime causing that product to come off? I would imagine that stuff would have a hard time staying put when subjected to wet and dirty environments. Just curious.

This is great info Baldilocks, thanks for sharing the pics. They really helped driving the point home. Looks like you used some type of black glue for adhesion.

I used liberal amounts of 3m weather strip adhesive and some very sticky aluminum tape in some places to adhere the material to the floor board. This was a couple years ago and it’s still 100% secure.