Insulation Question for the Experts! Sealing the lower section to the floor.....

[fastmerc]

Guys, and goils if you're so inclined....

Working on an existing 30x50' tin building by Vector Products, Central CA 15-20 miles from Pacific ocean, with moisture in the evening fog blowing in! 40 years old. NOTHING insulated at time it was built....ugh! Cheap *******! )))
I get weeks of close to freezing and weeks of 100+ temps or close with onshore breezes warming in the cold months and cooling in the summer afternoons, so it's bearable, but the humidity just dorks with everything.....machine tools, bare metal car pieces.....chrome.....

My problem is humidity raining down on me....... if I close the two top ridge vents. If I don't close the vents, I can freeze my **** off.....or worst case blow dust all over the place but it stays dryer!!!! I'm in Central CA in a rural farming area and the dust generated here by nearby road destruction (at the moment) and farmers getting ready for crops, is incredible!!!! SOOOO, I'm trying to close up my building to the point where I can close off my vents 100% and insulate up to them but leave the option to open them..... OR if insulating right over the top of the opening is an option.....I may just do that......but feedback on the moisture thing if I do this would be appreciated. Would hate to simply make my problem worse! I have electricity in the building, but no gas....

****!!! Why I am here at the moment is to ask about sealing my insulation to the floors. I am using expanded polystyrene (EPS) core with a printed, and metallic-reflective polymeric facer.... (Don't expect your cell phones to work in your building after putting this stuff up!!! Like working in a Faraday cage!!) )) Prior reading has suggested a 1/4 tp 1/2" gap and then foam seal. My insulation is being held to the wall by half a dozen of my DIY 3/4" stand offs several around the outside to fit to other panels, and a couple on the inside to keep them from flexing too much if pushed against...... This will leave a nice air gap to provide additional cooling and retention of warmth....barrier. The gaps at the bottom of the tin panels profile will be enough for the building to breath... up the walls to the ceiling and out eventually I'm trying to seal off the inside......

Not putting the insulation directly on the floor is recommended so that water or liquids do not get wicked up into the material if exposed. This EPS stuff isn't supposed to do this with water...... not sure about other liquids.......chemicals.....so this is contributing to my interest in a solution to my question above.

SO, at the bottom of my panel, I don't really have anything to seal against.....and I was looking for creative ways to do this...... a 1" square piece of tin tubing would be great....but I don't think anyone makes such a thing. I've looked at various 90 degree bent pieces of tin at Home Depot, but attaching them to the wall is another can of worms, to clear existing fasteners coming in from the outside, and providing a uniform fit all around....where it looks like 4 different people worked on the building putting it together.....different standards for each side....! ))))

OR do I just use the 1/4" gap thing and foam away....trim once it hardens.

I'm also thinking about cutting little trapezoid pieces to push into the tin panels where the profile moves out from the foundation about an inch or so....typically about an inch in three spots per foot..... to keep the critters out. Bugs....they don't do well in tin buildings.....and they don't pee all over cars and eat seat cushions.......typically! Just over size them a tad and cut out of 1/4 galvanized mesh and push them into the holes.....friction will hold them in place. Rodents won't get thru....unless they come in the front door!!!
Second pic has best view of bottom edge where the tin attaches to the floor via 90 degree sheet metal.

I'm only about 50% done with ceiling (bubble type insulation) due to wife keeping me off scaffolding while her broken leg healed.......and then while recovering a bit..... SO I started on testing out various theories on installation of the wall boards. I have two sections of about 11 sections done....if you chop the building in quarters and then "above and below" gurts.... North wall probably won't get much, as it has the roll up door, and the man door, plus it doesn't but barely catch any sun......AND I would like to put another 10-12' door on that side...... so doesn't make much sense to worry about it now.

I'm using tin wall studs chopped into 5 & 10" pieces then reforming the open edges to go from a 1/4" glue area and 1.3" thick sides (tall) to a 1" tall piece with 3/8+" glue area....This got me into trouble where I was passing my some iron pieces....a little tooo tight.

So my latest round of rebent pieces are now aprox 3/4 to 13/16" tall and will allow insulation to slip by the tight spots better!

OK, back to marking up my wall Lower section in this pic. This section is 15' wide and 7' tall to the gurt. Three pieces of insulation to cover...just need to come up with plan for lower edge!

Thanks guys!!!
Steve

 

[chinboys]

Four words... Stop the air infiltration.

This air infiltration is part of the three modes of heat transfer called convection heat transfer.
The other two modes are conduction and radiation heat transfer.

Moisture from the relative humidity air from the outside must not be able to infiltrate.

Did you know that most of the energy used in heating or cooling is to remove the relative humidity of the unconditioned air in an interior space? This process is called latent heating or cooling. Once the latent energy is removed (cooling), then your AC uses less energy to drop the temperature (sensible heat).
Use a ceiling fan or anything to circulate the air. You will find you can set the temperature higher or lower because you have interior air circulation.

Do what you must to reduce the number of passive air exchanges per hour. I prefer spray foam and adequate door and window gaskets.
Get a blower door test to see how less leaky your space is afterward or use the results to reduce the air leaks further.

If your building is now too tight, I would add an energy recovery system to exhaust the stale air while extracting the energy from it to that of the new fresh air.

 

[fastmerc]

Chin,

Thanks for the very detailed description of how this works! I understand humidity....grew up in MN and mom still runs a dehumidifier all summer and a humidifier all winter!!!

I had to laugh a tad at the smoke test suggestion...... My building probably leaks worse than a screen door canoe!!! But I hope I'm doing what I can to seal it up best as one can. Sounds like the "insulate the peak vents closed" from what you are saying is the way to go.

I also like the idea of a circulation fan. Gonna see what I can do to get one of those solar attic fans and mount it up high to come on once the sun comes up.......goes off when the sun sets...... Should be a pile of those available these days! Put one of those on our house attic and IMMEDIATELY the next day you could tell that the house was cooler in the summer!!!

Thanks again!
Steve

 

[fastmerc]

OK, perhaps I am not using the proper terminology in my question.

I understand how to install my EPS insulation boards to the wall, and I can handle sealing the top of the sheet to the bottom of the horizontal gurt, aprox 7' from the floor. (This is my "rim" board") Leave a small gap to fit the sealing foam nozzle/tube in and squirt away..... Seal seal seal......

My concern is the bottom of the wall insulation board. There is no wooden sill plate other than what the outer tin pieces are fastened to, which is a 90 degree piece of galvanized steel/tin 2" at the base and 2.5" or so vertically. See pics....

My concern is how much gap do I leave between the floor and the insulation sheets? I had always read about keeping the material off of the floor.....but never found a good answer for tin building...... I don't think my concern is so much water, but the septic tank has been known to plug up and be a ****** and over flow....., but potentially gasoline, or brake fluid, or other odd chemicals like lawn care.... I know it could take a lot of leakage to get to a wall......just going by what is recommended that I've read......which is what I cannot find for tin buildings!!! What I am seeing in houses... is to use a wood sill plate and install wall board with a gap...then foam the gap. Well, this tin building isn't getting wooden sill plates....that just sounds like a cluster flop of a job to make that look proper.....or even get it to work....

What is the practice of insulation board companies working with tin buildings or vice versa in this area???

Couple of pic's of the floor to wall "sill" and my DIY wall board spacers. (Tape is just holding for pictures....and for holding while glue is setting....no glue on these two yet!)

Tomorrow I'll be gluing the spacers to the tin wall with Boss 180 Pro adhesive, and then wait a day for adhesive to cure. If the answer is "leave a 1/8" or 1/4" gap and then seal with "Right Stuff" foam or similar, I can handle that. Just that I cannot find that recommendation or a recommended practice anywhere! Again, not enuf tin building guys....... and nobody seems to worry about it around here......! Aaaagh!

Thanks!!!
Steve

 

[67CarGuy]

So if I'm understanding your situation and question(s) correctly, you don't want to run your rigid vertical insulation all the way down to the top of your slab, because you're concerned about chemicals mucking up the insulation?

Some other questions for you:

• Are you planning on any further interior framing? I'm presuming not, given that the metal wall panels are already hung up.
• Why do you feel the need for the spacers between the metal panels and the rigid insulation? Moving air will carry a lot more heat (and thus moisture) than non-moving air.
• You state that you have a lot of moisture, and if you close your ridge vents that you get even more moisture. Do you know where the moisture is coming from?

 

[fastmerc]

67cg,

Basically yes, apparently "some" insulation will absorb water and be damaged by chemicals. The EPS material is less of an issue in this area....but I don't want to trap moisture on the bottom plate the tin is attached to. Would rather than it drain off.....dry off.... Again, this is me over thinking everything.....cuz that's what engineers do...... I'm just not schooled in the fluid sciences.....of air and water flow....

Other questions, and thanks for asking!!!

1) Nope, no interior framing. Boat has sailed. Building is getting work benches (with back splashes for catching tiny flying things....) and parts racks for hiding things I need to find later.....thirty years of Ford and some Dodge bits....

2) The spacers were to promote the travel of air to dry any moisture collecting on the inside of the tin during the wet months...nights... This was something mentioned in numerous discussions....unless I was reading the same ones over and over.....! I was also under the impression that the air gap would provide a thermal barrier of some sort....warmer in winter.....cooler in summer.......
Spacers also give me something sturdy and not wood, to screw the insulation material to.

3) Lots of moisture is semi seasonal. I'm about 15-20 miles from the Pacific swimming hole. There is a land feature called the Watsonville trench that comes up from the coast and dumps right straight into my little valley.....I can see it out the front window. I don't have any other mountains/hills in front of me to deflect it away as so many others benefit from in the area. Also get toooo many damn windy days as a result of it! It DOES keep it cooler in the summer though.....just you need to nail your paper plates down to the picnic table......

SO the humidity at night will climb to oceanfront levels, and then drop to desert conditions early in the day...... The building tends to be a giant dehumidifier if the vents are not open to allow air to circulate. The moisture tends to collect on the iron components as well as the tin I believe, and will rain down in the shop at certain points.....that it gathers on. Leaves "where the heck did that come from ?" puddles....

I looked into other options, spray foam....lost interest when the price was $35K for a 3 car shop...... but then everything is $35K around here these days......tin, labor to put up tin, permits to allow someone to put up tin, concrete, water connection, fire system..... Dumped my plans for a second building.....was getting ridiculous dealing with the county turds..... Containers are looking better every day.....

There is also much controversy or talk about do or don't foam. Could never get a straight answer from the building companies..... They all seemed to foam the iron but batten the walls and leave an air gap...... After that they say "go talk to an insulation installer......." Ugh.

Another opinion of which I can align myself with is sealing the inside of the building and letting the outside skin breath. That way the inside never gets moisture from the outside. Sealed box inside a leaky box. ....and my box leaks. I can't say that the old boys that put this thing together were all that sharp...... I have one wall that I need to "finish" putting screws in the tops of the panels as there are none for 50'! That dude was sleeping or drinking too much at lunch..... It's not rocket science! I just repaired /plugged a couple of leaks in the roof today where the guys missed the purlins and or double punched and didn't use additional sealer..... PITA! But making it mine!

Once the inner building is sealed as best you can, (not sure about sealing up the 10' rollup door......that seems to be a "naturally leaking" sort of device at the top edge up against the tin......not sure if there is some sort of "wiper" seal that would/should be there or not.....) the plan is to install a circulation fan in the peak. If I can get a solar operated one that would be the cat's meow!!! Come on with the sun and go off with the sunset! Put on in my other house 20 or so years ago and could tell it was helping the next morning!!! Was already cooler...and stayed that way longer in the summer!

OK, I think I addressed your concerns about my concerns. Thanks for the contribution! If someone else can learn from my adventures....that would be fine.

Kind regards,
Steve