Another carport style building insulation question.

[Andersonst]

I've read and reread many discussions about using the bubble wrap foil insulation in a carport style building (eversafe). The building is not installed yet and I have the option of having the building wrapped during install or not. I could not have it wrapped and then use 1.5" rigid foam boards with the foil facing towards the metal skin leaving approximately 1" of space between the metal skin and the boards and then plywood the walls. I'm assuming if I have it wrapped and I also install the foam boards that would create a problem. Not sure what's the best way to do this. Not sold on spray foam but not out of the question. I'm in Northwest Florida so hot and humid.

 

[dougf]

Everything I have ever read about the double bubble foil wrap is that its **** and not worth the money one bit. I don't have any personal experience with this, besides I opted out of that when my Carolina carport building was erected. I have dove head first into a headache with the building. I made the slab 1' wider and longer like they said (do not do this), elected for no wrap, and had them install the standard 5' on center vertical 2x2 metal studs. If at all possible have them install 4' on center studs, it will make your foam insulation fit so much better.

If I had to do it again I would fix the slab and get the inside spray foamed before I moved a single thing inside, had the 4' on center studs and finished with plywood or OSB and have been done with it. If you want to see a headache ill post pics when I get home of what I am talking about and the headaches you may encounter.

 

[Andersonst]

Everything I have ever read about the double bubble foil wrap is that its **** and not worth the money one bit. I don't have any personal experience with this, besides I opted out of that when my Carolina carport building was erected. I have dove head first into a headache with the building. I made the slab 1' wider and longer like they said (do not do this), elected for no wrap, and had them install the standard 5' on center vertical 2x2 metal studs. If at all possible have them install 4' on center studs, it will make your foam insulation fit so much better.

If I had to do it again I would fix the slab and get the inside spray foamed before I moved a single thing inside, had the 4' on center studs and finished with plywood or OSB and have been done with it. If you want to see a headache ill post pics when I get home of what I am talking about and the headaches you may encounter.

To be honest, I'm getting a headache researching all the insulation options.
My slab is poured the same size as my building, we'll sort of, my slab is 30x60 and my building is 30x40 enclosed with a 20 foot front porch/overhang.
I think I'm leaning towards not getting the wrap (3600 bucks for entire enclosure) and using 1.5" foil backed rigid foam boards inside the 4 foot legs, yes I opted for the 4 foot not 5 foot, and across the ceiling. If I do it this way, will that effectively create my radiant barrier and moisture barrier and have some insulation?? And then cover 8 or 12 ft up the walls with plywood. It has 12 foot high walls.

 

[Andersonst]

To be honest, I'm getting a headache researching all the insulation options.
My slab is poured the same size as my building, we'll sort of, my slab is 30x60 and my building is 30x40 enclosed with a 20 foot front porch/overhang.
I think I'm leaning towards not getting the wrap (3600 bucks for entire enclosure) and using 1.5" foil backed rigid foam boards inside the 4 foot legs, yes I opted for the 4 foot not 5 foot, and across the ceiling. If I do it this way, will that effectively create my radiant barrier and moisture barrier and have some insulation?? And then cover 8 or 12 ft up the walls with plywood. It has 12 foot high walls.

 

[Andersonst]

Other then price, what are the pros and cons of spray foam? I can do the foam boards for less then half the cost of spraying it.

 

[dcg9381]

Other then price, what are the pros and cons of spray foam? I can do the foam boards for less then half the cost of spraying it.

Advantages:

• It can be done in a day (just a few hours in some cases)
• It's pretty much superior as it expands and tends to get in gaps/cracks. Helps seal the building. It really seals the envelope
• They say closed cell is "structural"

Cons:

• It will eventually burn if heated enough (plywood OSB is would burn first, add another 300 degrees to ignite foam)
• Price
• Not a "green" solution in terms of chemistry
• Saw a project here with 29 ga siding where the foam expansion slightly warped the panels... I think this is specific to 29 ga steel.
• Saw another project where the claim was that the building didn't leak until foam was applied.

I've done 3 structures with open cell foam, I'll keep using it...

 

[Andersonst]

I just got off the phone with a spray foam guy and truthfully I like what it offers, 2" on ceiling and 1.5" on walls closed cell. The pros appear to outweigh the cons.

 

[dougf]

I just got off the phone with a spray foam guy and truthfully I like what it offers, 2" on ceiling and 1.5" on walls closed cell. The pros appear to outweigh the cons.

I got my roof spray foamed directly to the metal with 1.5" of closed cell of my 20x30 metal building for $1,200 and it made an incredible difference. I am doing the walls with the 1" foam board with the foil backing. I am doing the foil backing facing outward and I used a can of foam to attach it to the metal. I then foil tape to the metal studs. It seals really well. I am really glad to hear you got the 4' on centers studs, its going to make your life a ton easier. If you have the moneuy spray foam it all immediately, then the next day you can start screwing up plywood or OSb and you will save months of cutting and fitting foam and it looking like hell.

 

[wes3337684]

I have a 30x40x12 Carolina Carport style garage and I skipped the bubble wrap and found a place selling 2 1/2 inch thick, 36 inch wide and 125ft long fiberglass insulation, I cut to fit between the posts and bought 10ft sheets of white metal to cover the whole inside of the garage. Turned out great and very bright inside.

 

[u2slow]

The main 'pro' with spray foam (imho) is the air seal so you can install HVAC for climate control.

My car-port is wood frame (post/beam) with 2x4" framed filler walls. I'll use R14 roxul batts if/when the time comes.

 

[Andersonst]

Skipping the bubble wrap is going to happen for me to. It's sounding like spraying it is the way to go. It appears to check all the boxes, but I will say it's NOT 1200 bucks. Of course I'll be doing walls and ceiling. Just spray it and move on right....

 

[Andersonst]

I got my roof spray foamed directly to the metal with 1.5" of closed cell of my 20x30 metal building for $1,200 and it made an incredible difference. I am doing the walls with the 1" foam board with the foil backing. I am doing the foil backing facing outward and I used a can of foam to attach it to the metal. I then foil tape to the metal studs. It seals really well. I am really glad to hear you got the 4' on centers studs, its going to make your life a ton easier. If you have the moneuy spray foam it all immediately, then the next day you can start screwing up plywood or OSb and you will save months of cutting and fitting foam and it looking like hell.

Is there a reason why you only did your roof and not the whole thing?
A different question, has anyone hung wall cabinets or anything up? Any issues? Or a suspended shelf of some sort attached to the roof deck frame and walls?

 

[housewolf]

Is there a reason why you only did your roof and not the whole thing?
A different question, has anyone hung wall cabinets or anything up? Any issues? Or a suspended shelf of some sort attached to the roof deck frame and walls?

I hung cabinets before they sprayed so they covered the cabinets before spraying and just filled the void behind the cabinets with them in place. I only have a couple so it wasn‘t a big deal. I have a small shop (18’x35’x12’) so almost everything in it is on wheels. I can rearrange things depending on whether I’m doing automotive, woodwork, or metal.

I went with the insulators recommendation and sprayed 5” of open cell on the roof and 2” closed cell on the walls. The walls & ceiling were left exposed but they’re mostly covered by shelves & eqt.

The insulation helped significantly. In the summer when it was high 90s I was seeing 110+. Now it’s same or A little less than outside temps. I’ll install a mini split in the spring so I’m hoping to be able to see low 80s next summer

 

[Spud McGee]

Advantages:

• It can be done in a day (just a few hours in some cases)
• It's pretty much superior as it expands and tends to get in gaps/cracks. Helps seal the building. It really seals the envelope
• They say closed cell is "structural"

Cons:

• It will eventually burn if heated enough (plywood OSB is would burn first, add another 300 degrees to ignite foam)
• Price
• Not a "green" solution in terms of chemistry
• Saw a project here with 29 ga siding where the foam expansion slightly warped the panels... I think this is specific to 29 ga steel.
• Saw another project where the claim was that the building didn't leak until foam was applied.

I've done 3 structures with open cell foam, I'll keep using it...

For me, the big con I'm seeing is difficulty with future maintenance and repairs.

 

[Lastrohm]

We just had our metal garage sprayed with closed cell this summer. So far we have been happy with it other than it isn't pretty! As the wife, I found it expensive. Husband not so much! Cost little over $5,000 for a 21x 35 x10 building. We made the mistake of having cement slab 1 foot larger than building like the garage company required. Big mistake. Having hard time keeping rain out even after calking around walls.

 

[MistrGoodwrench]

I made the slab 1' wider and longer like they said (do not do this)

Carolina Carports told you to do this? I'm pouring concrete this week. They told me 8" wider than the dimensions of the building (4" in each direction).

 

[Andersonst]

Carolina Carports told you to do this? I'm pouring concrete this week. They told me 8" wider than the dimensions of the building (4" in each direction).

They told me to make the slab the same size as the building so the sidewalls hang down over the bottom frame and a little over the concrete. That's what I did. They're actually installing my building as we speak. My concrete extends past the front wall as there's a 20 foot porch on it.

 

[Scotto]

Carolina Carports told you to do this? I'm pouring concrete this week. They told me 8" wider than the dimensions of the building (4" in each direction).

That's asinine IMO. All it does is make it easier for them to install so you can have a lifetime of water penetration issues later on. I guess they really are selling a "carport" where it doesn't need to be watertight.

 

[MistrGoodwrench]

They told me to make the slab the same size as the building so the sidewalls hang down over the bottom frame and a little over the concrete. That's what I did. They're actually installing my building as we speak. My concrete extends past the front wall as there's a 20 foot porch on it.

That's what I expected but they confirmed that it needed a 4" apron. Makes no sense to me.

 

[nadogail]

I am confused about why anyone would insulate a post supported roof over a parked car. I n my limited experience a Car Port has no doors or walls, just a roof to keep the sun and most of the rain off your car.

The only places I have lived that had Car Ports have been in Hawaii and California. One of the California carports was open on two sides, the entrance and one end wall, it was part of a multi family apartment building.

What am I not understanding? If it has walls and a door it is a garage not a carport.

 

[MistrGoodwrench]

I am confused about why anyone would insulate a post supported roof over a parked car. I n my limited experience a Car Port has no doors or walls, just a roof to keep the sun and most of the rain off your car.

The only places I have lived that had Car Ports have been in Hawaii and California. One of the California carports was open on two sides, the entrance and one end wall, it was part of a multi family apartment building.

What am I not understanding? If it has walls and a door it is a garage not a carport.

In this context it's a style of metal building. Usually with square tubing structural members as opposed to red iron beams or wood construction.

 

[dcg9381]

We just had our metal garage sprayed with closed cell this summer. So far we have been happy with it other than it isn't pretty! As the wife, I found it expensive. Husband not so much! Cost little over $5,000 for a 21x 35 x10 building. We made the mistake of having cement slab 1 foot larger than building like the garage company required. Big mistake. Having hard time keeping rain out even after calking around walls.

I did a 40x60x16 for $5k in 2-3" of open cell spray foam in 2018. I don't think prices on it have swung as high as other things... It may be a regional "competition" thing also.

I'd be pissed about the slab too.... That's a pretty big screw up.

 

[Andersonst]

That's what I expected but they confirmed that it needed a 4" apron. Makes no sense to me.

What they told you doesn't sound right to me so I asked my installer and he said it definitely should be the same size so the sidewalls can extend past the concrete. Mine is going to extend about 2 inches and that makes perfect sense.

 

[MistrGoodwrench]

What they told you doesn't sound right to me so I asked my installer and he said it definitely should be the same size so the sidewalls can extend past the concrete. Mine is going to extend about 2 inches and that makes perfect sense.

I've asked the parent company for clarification. I see no way a 4" offset will allow the metal to extend past the concrete.

 

[Firebrick43]

Don't forget that Con of sprayfoam directly against the metal voids the warranty. And if it leaks, and all exposed fastener metal buildings will some, and carport style buildings with metal run horizontally will even more, the foam will slowly absorb water as during the freezing/thaw cycle it will rupture the cell walls and will continue to work its way in. Buy the time its noticed it will have caused a lot of corrosion already.

If you place solid foam between the uprights and building even a 1/2" air space that water will run out and down to the ground and moisture evaporate as there is airflow.

 

[dougf]

They did tell me to do this, so it's what I did and was a huge mistake. I have 6" of slab around the entire building. I should have questioned this more. I think they tell you to do this so the "installers" dont blow out concrete edges with their anchors. Man I wish I could do my building over again!

EDIT: I was present when it was installed. I layed a thick bead of urethane sealant (Vulkem brand from Lowes) under the base plate which really helped prevent water intrusion, but didnt completely stop it in some spots. I highly recommend anyone getting one of these installed to do the same. I keep forgetting to post pics.

 

[dougf]

Here's some pics of the inside of my 20x30x10 if anyone wanted to know how to insulation turned out and get some shelving ideas. Still not done. Roof was spray foamed 1" closed cell, and i'm installing polypro foil backed sheets in-between the vertical "studs". Its a real pain in the ****! Mulling the idea of kicking out the back wall next summer 10' for more room then sheeting it all with plywood to make it look better and assist with hanging stuff, looks like hell right now. I am grateful for it, I just wish I would have done the 4' on center studs, spray foamed it all before moving anything in, slab the same width as the building, and upgraded the thicker gauge tubing and siding. Hopefully these pics help in your decision making process.

 

[MistrGoodwrench]

Well, I got an answer, sort of. It isn't called out on the plans but they sent this pic of how it's supposed to be installed with a 3/4" step built along the perimeter of the slab when it's poured.

 

[Andersonst]

Well, I got an answer, sort of. It isn't called out on the plans but they sent this pic of how it's supposed to be installed with a 3/4" step built along the perimeter of the slab when it's poured.

That certainly makes more sense to step the slab down but why not just make it the same size. I talked with my installer again today about this and he said absolutely make it the same size unless there's a reason not to.
Well my installers finished and are done. Here's some pictures, quite happy with the results, now onto insulation, power, water, interior finishing....etc, etc.....

 

[MistrGoodwrench]

That certainly makes more sense to step the slab down but why not just make it the same size. I talked with my installer again today about this and he said absolutely make it the same size unless there's a reason not to.
Well my installers finished and are done. Here's some pictures, quite happy with the results, now onto insulation, power, water, interior finishing....etc, etc.....

Looks great!

 

[Andersonst]

Looks great!

Thanks, the guys did a good job, a bit of a language barrier and 4 billion screws on the ground, got em picked up but you know there's going to be that one.

 

[manwithtools]

Time for a magnetic sweep:

Magnetic Sweep

 

[scofo]

Congratulations, it does look nice. That porch extension looks handy for washing stuff down before it comes in the shop.

 

[Youngandfree]

That certainly makes more sense to step the slab down but why not just make it the same size. I talked with my installer again today about this and he said absolutely make it the same size unless there's a reason not to.
Well my installers finished and are done. Here's some pictures, quite happy with the results, now onto insulation, power, water, interior finishing....etc, etc.....

Looks great. I've got an itch to do the same style, with 30×50 encloses and 15 or 20ft open. One wide door instead of 2.

 

[Andersonst]

Time for a magnetic sweep:

Magnetic Sweep

We did use a magnet and got most of them and I raked all around and got a bunch more but every time I walk around out there I find another one. Not complaining just mentioning.

 

[Andersonst]

Congratulations, it does look nice. That porch extension looks handy for washing stuff down before it comes in the shop.

Washing off the orange Florida dirt road, working outside under the overhang and not being directly in the sun, just hanging out under, that's going to come in very handy indeed.

 

[Andersonst]

Looks great. I've got an itch to do the same style, with 30×50 encloses and 15 or 20ft open. One wide door instead of 2.

Go for it I'm happy I did. I do wish I'd have made the overhang 25' instead of 20', 4 door F350 with 8' bed doesn't quite fit under but oh well. I like the 4' extensions past the enclosed portion to act as a wind/rain block to.

 

[Youngandfree]

Go for it I'm happy I did. I do wish I'd have made the overhang 25' instead of 20', 4 door F350 with 8' bed doesn't quite fit under but oh well. I like the 4' extensions past the enclosed portion to act as a wind/rain block to.

I want to be able to back my Tundra and 14ft trailer in for the night so I don't have to unload my mowing gear. I think I'd like vertical siding as well.

 

[Andersonst]

Let me ask you guys this, which comes first, spray foam insulation or running the electrical wires? I've read both in various places. I'm thinking insulation first so my wires are not all covered. I'm putting 2" in the ceiling and 1.5" on the walls (closed cell) so there's still room to run the wires and boxes and switches etc. Will probably be putting 1x4 firring strips horizontal against the metal legs and attaching plywood walls.

 

[housewolf]

Let me ask you guys this, which comes first, spray foam insulation or running the electrical wires? I've read both in various places. I'm thinking insulation first so my wires are not all covered. I'm putting 2" in the ceiling and 1.5" on the walls (closed cell) so there's still room to run the wires and boxes and switches etc. Will probably be putting 1x4 firring strips horizontal against the metal legs and attaching plywood walls.

I ran conduit in mine, they just sprayed them too. I’ve since run a little more that isn’t sprayed. No big deal IMO. It is easier to attach conduit to the bare steel than over, or scraping off, insulation