Insulation

May 31, 2023
55
O'Day 22 Redlands, CA
I'm in the process of refurbishing an O'Day 22. I'm considering insulating the interior with ¼ inch Styrofoam. What are the advantages or drawbacks to doing this?
 

jssailem

SBO Weather and Forecasting Forum Jim & John
Oct 22, 2014
22,217
CAL 35 Cruiser #21 moored EVERETT WA
What do you want to insulate against?
You need to ask, what is the R factor of 1/4" styrofoam?
What will happen to the styrofoam if you bump it?
Will it break apart and leave little white foam balls everywhere?

I suggest closed foam glued to your interior, with tape seals to eliminate gaps between foam panels.
 
Mar 2, 2019
507
Oday 25 Milwaukee
When it came time to replace the original tan burlap . We chose an indoor /outdoor carpet . As the boat sits in the relatively cold water of Lake Michigan for most of summer , keeping the boat some what warmer was important . The carpet was installed with a water based adhesive . The boat became much quieter as well . Going on 18 years and it still looks great . We choose a light blue to keep the interior as bright as possible .
 
Aug 7, 2015
99
Oday 34 previous, O’Day 40 current Annapolis
The R value of 1/4” styrofoam is diddly, doubt you will notice the difference & working w/styro would be a pain. I’ve experimented w/ a bubble wrap layer on top of my fridge & it marginally seems to improve heat rejection though the science doesn’t support my result- almost anything to reduce the loss through the top of the frig.

Carpeting, though having little stated ‘r’ value may do a lot to provide& retain a warm air film on the interior- think I would give it a try if your interior is worn or dated. Otherwise, to make a difference you’ll need at least 1” of polyiso (R-5 or so)

Lou K, architect
 
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May 31, 2023
55
O'Day 22 Redlands, CA
I found this: Thoughts?

https://a.co/d/8ThWOH9

My plan is to glue it to the hull. I would like to glue furring stripping so I can screw 1/8 inch plywood to cover the insulation. I just want to make sure I'm not overthinking this. Thanks for the feedback.
 

dLj

.
Mar 23, 2017
3,836
Belliure 41 Back in the Chesapeake
Ok, I have to ask - what is it you wish to accomplish with this insulation? Any material you choose applying under an inch thick is not going to give you practically any thermal insulation. If you are desiring some amount of thermal insulation, you would be better off looking at ways to create a very well sealed vapor barrier with an airspace behind it. At least in the thickness ranges you've been suggesting.

dj
 

jssailem

SBO Weather and Forecasting Forum Jim & John
Oct 22, 2014
22,217
CAL 35 Cruiser #21 moored EVERETT WA
I think a material more like this would be better than 1/4in styrofoam.
 
Aug 7, 2015
99
Oday 34 previous, O’Day 40 current Annapolis
If you want to get serious, spray foam which has generally relatively high R-values ranges from 5.5.- 7 per inch and residential construction requirements for walls average between R13-19 depending on where you are located.
Adding a layer of wood to the inside over sleepers would effectively increase the r value of the assembly a very small amount. The foam rubber shown has maybe an r-value of 1? You really must consider 1/2” or 1” to get anything of value. Simply can’t negotiate the physics if heat transfer.
 

dLj

.
Mar 23, 2017
3,836
Belliure 41 Back in the Chesapeake
If you want to get serious, spray foam which has generally relatively high R-values ranges from 5.5.- 7 per inch and residential construction requirements for walls average between R13-19 depending on where you are located.
Adding a layer of wood to the inside over sleepers would effectively increase the r value of the assembly a very small amount. The foam rubber shown has maybe an r-value of 1? You really must consider 1/2” or 1” to get anything of value. Simply can’t negotiate the physics if heat transfer.
+1

I'll add a bit to this - with spray foam you would want closed cell spray foam, they make both open cell and closed cell. Closed cell spray foam tends to be more expensive. There are two factors in insulation, the R value which is a measurement of how fast or slow heat moves through the material being used, in this case the R value is like the resistance for heat to flow so the larger the number the better the insulation.

The second factor is how leaky the wall, ceiling, whatever, is. In residential construction it's called the vapor barrier. Think about a plastic bag filled with water. If you have holes in the bag, the water leaks out even though the plastic bag contains the water well. Similar with insulation, of you have holes in your insulation, the heat just leaks out (or in, think tropics).

The advantage of closed cell foam is it has a high R value, and it adheres to the surfaces it touches making a good vapor barrier at the same time.

Whatever material you decide to use, when doing the application keep in mind those two aspects of putting in insulation. You want both good insulation and a good seal.

dj