R-13 insulation adequate?

[ilyafish]

I am going to insulate the roof and everything i can besides removing the panels under the windows, but that is okay because there pretty much is going to be no exposed wall, everything is going to be either a bench couch or something else.

Spray foam is pretty pricey so i was wondering how well of a job it would do if i just got some r-13 and stuffed it

[vaunter]

squishing insulation kills its r value
id doubt you would get more than 1-2r from doing it that way
i used 1-1/2 in blue foam for inbetween the supports and covered that wth another 1/2 in pink foam
and wow what a diff that made from the factory insulation

[JohnEd]

IM,

Two things:  First, the rust that kills the wall strength is at the very bottom of the wall where it mates with the floor.  The rust is caused by condensation on the windows running down the inside of the wall so anything from the north will have it.  from what I have seen the guys run a diagonal brace betwee each vert stud for added strength and to compensate for the removal of the metal on the inside of the wall.  I suggest you rethink your decision to not remove that sheet metal from the bottom of the wall unless you can verify that you have uncompromised steel in the wall bottoms.

Second, fiber glass is worthless if it is wet.  MCI, in it's wisdom, packed their insulation in plastic baggies to keep the stuff dry and glued the baggies to inside of the exterior skin to keep them in place.  Even at this they got wet somehow.  Incidental, fiberglass settles with vibration and eventually leaves a void at the top of a filled chamber.  A lot of the heat loss in a bus is due to air permeation and only foam stops that cold(no pun).  I suggest you rethink your decision to use FG instead of foam, either hand fit or sprayed.  Both give about the same R value but sprayed seals air and quiets the coach significantly.  Both cost about the same if you believe what you read.  Save you money and have it sprayed and scrimp somewhere  else.

Know for sure that I and others will cheer you on even if you elect to go with Papier Mache.  To each his own.  Good luck,

John

[Sojourner]

I might add along with JohnEd posted. While my bus was in bare shell…with no ceiling and wall inter skin…it rain inside every morning before the sunshine warm up the outer skin. Wherever you are, if the area climate is high humidity and/or any human body living in a metal tent, it will produce drops of water to moisten whatever next to it or below it (fiberglass insulation).
So the best advice is to use hot foam spray-in by well equips professional that come a special trailer or small truck to do it about the same price as do-it-self kit…not to forget…the kit don’t come with heater to increase the foam bonding and harden after it cooled.

However the second best choice (and lower cost) is ridge blue or pink or Tuff-R foam. The main thing is to fit it tight in between joints so that no humidity can get thorough toward the colder metal under surface to cause dripping. However, Weathermate tape is answer to the ridge foam gaps problem.

BTW…I have no business interest of their product but let you know it available a Lowes.

Tuff-R is polyisocyanurate foam equal R of 6.5 @ 1 inch thick.

Blue foam is polystyrene insulation equal R of 5.0 @ 1 inch thick

Weathermate Tape to seal all joints


New product as of 10/2007 SAFETOUCH™ Fiberglass-Free Insulation

Need to contact them if it will adsorb moisture?  If it does, then it not for metal tent enclosure. Remember the humidity from gas range, humans and open door to the outside air along with inside of the coach being air tight will absorb moisture to weaken the R effect.

FWIW

Sojourn for Christ, Gerald

[ilyafish]

I am going to be putting up plywood up along the walls, and squaring off the ceiling with plywood as well. from what i have heard, wood tends to work as a good insulator.....if i am not going to have everything covered in wood with no gaps, how well will that alone work as an insulator?

[TomC]

When my bus was stripped, I got rid of all rust, welded two cracks, and painted the entire inside with Rustoleum primer.  I then screwed 1x2 fir strips 90 degrees to the supports.  This makes the walls thicker, and gives a base to screw your walls and ceilings to.  Most importantly, it allows the spray foam to cover everything.  The problem with using foam block is that it is in between the metal supports, with the metal supports still exposed allowing either cold or heat in.  With sprayed foam, it quiets the bus, stiffens the walls, and seals not allowing water penetration.  I have 2.25" of foam insulation with single pane Peninsula lightly gray tinted windows that are very big.  In 107 degree weather driving down the road, I can keep the bus at 75 degrees with just two roof tops running.  Spray foam is a good investment-I will use the same technique again on my next conversion I am so pleased with the outcome. Good Luck, TomC

[busshawg]

I'm with Gerald and John. I did remove the inside lower panels. I was really debating this step but am very glad I did it. As John mentioned there was some bad rust on the supports, insulation was wet and worthless.  Many talk about these panels being stuctural but framing with rust doesn't help much either. I would keep shopping for a deal on spraying the isulation in. This has been a topic with some differances but the spray foam will also add to your structural support. Gerald mentioned the ridget foam insulation as a second choice, I agree as this is something you can do yourselve, but I do feel it is very important that you get to the root of the problem and get that original pink fibreglass in those bags out of the bus, and fix any leaks that the window frames may have. As John said do the insulation right and scrimp somewhere else. After the bus is done one can't really go back and add more insulation but one can improve lots of other things years after.

Have fun

[Zeroclearance]

I debated pulling my lower panels on my 102C3.   Everyone told me that there was rigid foam under them.   The guys in the bus barn told me that that the structure would be fine.   I decided to cut the welds and remove one panel to check.   To my disbelief there was rust and alot of it (there is rigid foam under the panels)  At the time I did not have my roof panels out and assumed that MCI had did something to improve the insulation from previous models.   Yellow fiberglass insulation glued to the roof panels with water sweating on the ribs.   All this water makes it way down to the beltline and eats out the vertical supports.

The horizontal steel rails are made of stainless, why didn't MCI continue up to the roof line with stainless and rigid foam.

Over the years I have read threads on this forum that they got a good deal on the spray foam.   Can we make a sticky thread, with contact names and cities that list companies or persons that spray the foam?   I am not there yet, and won't be there for a few years.   I think it would help swing people to getting it done.

[turbobrat930]

Over the years I have read threads on this forum that they got a good deal on the spray foam.   Can we make a sticky thread, with contact names and cities that list companies or persons that spray the foam?   I am not there yet, and won't be there for a few years.   I think it would help swing people to getting it done.

I think that is a very good idea....

[Sojourner]

As John said do the insulation right and scrimp somewhere else. After the bus is done one can't really go back and add more insulation but one can improve lots of other things years after.

Have fun

That the main thing you want to avoid to redo it later after all the interior is installed. The cost of good insulation project part of having enjoyment of traveling in comforting of either warmed or cooled home to live in at the lowest fuel cost...not to mention the sound reduction.

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About the R in materials
Please read Typical R-values paragraph and see what each material is R rated

About OEM inter metal panels….you will hear someone say it structural which is incorrect. Ask them how many rivets per foot and what type of rivet being used?  They will tell you it less than 10 rivet per foot and using pop rivet without mandrel…which is NON structural. An illustrated example of pull type structural rivet (left click)  Also solid rivet is structural.

There must be at least 10+ of 3/16 inch diameter structural rivet per foot on monocoupe constructed buses. They can be in stagger or straight line format. Stagger is stronger of the two.

FWIW

Sojourn for Christ, Gerald

[JohnEd]

Im,

The R value for 1/4 inch ply is .31R.   For foam the same thickness would be @ 1.6R or slightly less than 6 times the R value.   With that said, I would offer that "wood has no appreciable R value".... Go with foam or stay in Key west with the windows open.   i suggest that you decide that this, spray foam is the "ONLY" realistic way to go and plan accordingly. 

Tom gave you solid advice with the firing strips.  I would add that you should drill all the vert studs and shoot foam in the stud every 6 inches.  If the stud volume isn't filled the stud transmits lots more cold than if it is.   Whatever condenses will drain into the bottom of the wall, as well.

Just some of my thoughts here Bro Knut.  We are all on your side.