Partial Spray Foam?

[duluthUPLAND]

Thanks in advance to the GJ forum. New forum member here and have found a lot of great info.

My house came with a spare 24x24 wood frame garage on a slab that is unfinished except for electrical and some cabinetry and shelving. I live in northern MN so in the winter it has been nothing more than cold storage.

I'm finally moving ahead on building out the garage to make it usable space for me and the bird dogs. I work from home so if I do it right, my home office will move out there as well.

Still researching all options but heating/cooling and insulation are all big decisions for me right now.

I've received three quotes from spray foam contractors ranging from $3250 - $5000+ ...I knew it wasn't cheap but that may be more than I'm willing to spend.

I'm now considering foaming the roof so I can keep the ceiling open and going with fiberglass in the walls. Of course that got me thinking, would I be better off foaming the walls and putting in a ceiling to blow cellulose up top?

Are there pros and cons to either of these set-ups? Does breathing/venting become an issue if you only foam walls or ceiling? I know I need to add venting if I go with drop ceiling and blow cellulose up top.

Cost is certainly a factor for me, but my main concern is that the space be well conditioned year-round. I'm considering a hyper-heat mini split for heat but I'm concerned about subzero temps in the winter, so I may need a backup heat source?

Appreciate anyone's thoughts on this project. Thanks!

 

[gogolf0401]

Greatest heat loss is through the roof and windows. Depends on what you want. Nothing wrong with vaulting and foaming that with fiberglass walls. From Detroit Lakes area myself. I foamed my walls and did cellulose in the ceiling in my previous shop. Was easy to heat... Love foam. Built a new house and did my house the same way. It will pay for itself in time.. benefit to foam is it appears to help keep the critters out.

Sent from my Pixel 3 XL using Tapatalk

 

[gogolf0401]

Forgot to mention, just do a hanging NG/LP heater sized for the space. They do a good job in my experience. Did my previous 40x88x14 that way and it hardly ran.

Sent from my Pixel 3 XL using Tapatalk

 

[duluthUPLAND]

Forgot to mention, just do a hanging NG/LP heater sized for the space. They do a good job in my experience. Did my previous 40x88x14 that way and it hardly ran.

Thanks for the input! Keeping critters out is a consideration, that was one of the reasons I looked at foam to begin with. I haven't had any issues in there yet but certainly don't want to start now...

I'm trying to avoid the additional expense of running a gas line back there if I can, but I know that would dismiss all heating concerns. That could be something I consider in the future.

 

[yeldogt]

2x4 or 2x6 walls --- I have done flash and batt ... but, you need 2x6 walls.

Nothing is going to match the foam -- the sealing properties can't be matched. What was your feeling when you spoke to the less expensive foam contractor?

Some of the bigger contractors have good prices because they can match the job to the equipment time. Just getting the trunk to the site and setup is a big chunk of the time/cost

 

[Black Oak]

Do you have vented soffits ? Ridge vent ? It all works together .

 

[duluthUPLAND]

2x4 walls and no vents currently.

The cheapest bid was minimal communication, estimate was done via text message so not as reliable.

I was quoted roughly $3250 for 2" on the walls and 3" on the ceilings which I could probably see myself spending however that was again the lowest bid and the one bidder that did not come out to see the garage. I may have to further that conversation.

 

[yeldogt]

2x4 walls and no vents currently.

The cheapest bid was minimal communication, estimate was done via text message so not as reliable.

I was quoted roughly $3250 for 2" on the walls and 3" on the ceilings which I could probably see myself spending however that was again the lowest bid and the one bidder that did not come out to see the garage. I may have to further that conversation.

That depth may or may not be enough .. what was the other quote depth.

With foam you don't vent. The point is to seal a structure -- why punch holes in it.

Foam gives a lifetime of payback .. I only remember hearing one person who regretted foam. That was on here ... and -- it was about payback. He did not think he would get the payback. It's not all about payback --- they are quiet and comfortable buildings -- that's worth something. My guess if we did the math -- the payback would be there.

 

[gogolf0401]

How warm do you intend to keep it heated?

Sent from my Pixel 3 XL using Tapatalk

 

[duluthUPLAND]

That depth may or may not be enough .. what was the other quote depth.

Thank you. Quiet and comfortable are both important to me. If I can't work out there reliably year-round the value proposition is skewed. I also do podcasting and audio stuff for work so the acoustic benefits of foam would be a major plu.

Here's the breakdown of the quotes I received from low to high:

Quote #1
2" walls and 3" ceilings = $3250

Quote #2
2" walls and 3" ceilings = $3750

Quote #3
2" walls = $1510
3" walls = $2250

3" ceiling = $2415
4" ceiling = $3215
5" ceiling = $4020

2" walls and 3" ceilings = $3925

 

[duluthUPLAND]

How warm do you intend to keep it heated

I'm not entirely sure. There's no water or anything but I'll have a computer and other stuff out there. Above freezing throughout the winter for sure.

I also will have dog kennels and bird dogs out there so enough to be comfortable for them but I don't intend to leave them out there all the time or anything.

 

[gogolf0401]

You'll want at least 2.5" walls. If keeping it at 70 you'll want 3. Ceilings should probably be 4-5. Again it depends on how warm and efficient you need it.

Sent from my Pixel 3 XL using Tapatalk

 

[egdede]

I'd consider foaming the walls and ceiling with 2" of foam; with blown cellulose on top of the ceiling foam and mineral wool filling out the walls.

 

[LX-Markham]

I did 2” on the walls and 3” on the ceiling. Unvented vaulted ceiling. Very happy with it. I would recommend doing all in foam.

 

[Ak Jim]

I did 2” on the walls and 3” on the ceiling. Unvented vaulted ceiling. Very happy with it. I would recommend doing all in foam.

Hey not trying to hijack this thread but what do you have on the floor of your garage?

 

[EricVonHa]

After spraying 5 sets of closed cell Lapolla into my garage mahal-- this is what I'd recommend from experience:

1. Quotes are all over the place from the contractors. Basically, the labor is 2 days, one guy for your building and the 2nd day is only going to be a partial clean-up, touch-up day.

2. Sign the lowest guy for the job. Why? Trust me, the difference between 2" or 3" is not an issue the guy with spray gun is going to care about. It is tough to spray anything less than 2" The spray guy/gun has to be moving mega fast in order to keep the coating thin. And, even then, the expansion of a basic layer "foams up" to be a minimum of 2". So, just buy the cheapest contract and be there to carefully watch as they are doing it.

3. If you're going to do it, do it right. Do the ceiling as well. The structural integrity of the foam is worth it alone. The insulation properties are well worth it, also.

4. In terms of raw cost between bat insulation and spray foam, think of the long term energy costs as a factor. Sure, the foam is a bit more expensive in raw materials cost (everything high-tech is) but the foam will seal your building forever in the tightest way possible.

Here's some more of my anecdotal input-- I can run the radiant floor heat boiler (80k Triangle) 2x per day for 15 minutes at a time when the outside temps are hovering at freezing-- the floor temp easily stays @ 55 degrees and the air temp likewise. I will only lose 2-3 degrees of temp overnight or 12 hour span without running the boiler.

Now, keep in mind that every building is different and the number of doors/windows, floor insulation, etc all come into play. But, I spent ~$12k insulating my 2-story building and sealed every perimeter wall and full ceiling with closed cell-- and the insulating properties are out of this world seriously impressive. I'm so glad I went all-in with it.

 

[LX-Markham]

Hey not trying to hijack this thread but what do you have on the floor of your garage?

That’s a double-wide 4-post lift in the down position. See build thread in sig.

 

[duluthUPLAND]

Well I thought I'd post an update on the garage project since GJ members were so helpful in my decision making process.

I decided to have spray foam put in and I'm quite satisfied. I went with 2.5" in the walls and 3" on the roof deck.

I added 4 new windows and have the walls put up. Leaving the ceiling open for now but may finish at some point depending on heating an conditioning needs.

I'll be installing a mini split unit and building out a workspace and some dog kennels. Hopefully ready to move my home office out there by the end of the month.

Adding some pictures of the official "before", spray foam and new windows installed walls up.

Thanks again to the GJ community!

 

[yeldogt]

Once spray foam is installed I always find it interesting to hear peoples reaction prior to adding any conditioning. My old studio w/ closed cell is still comfortable w/o ever turning on the AC . 1700sf -- but only 3 windows facing north west. Tight door.

Humidity becomes the issue before heat.

 

[duluthUPLAND]

Once spray foam is installed I always find it interesting to hear peoples reaction prior to adding any conditioning. My old studio w/ closed cell is still comfortable w/o ever turning on the AC . 1700sf -- but only 3 windows facing north west. Tight door.

Humidity becomes the issue before heat.

I noticed that immediately. I honestly believe that the heat pump is going to be working on my mini split WAY more than the reverse. The temp stays really consistent in there as it is. Not to mention the fact that A/C is far from our biggest concern in Duluth, but it's still nice to have.

I got the mini for humidity control and I'm hoping to get a decent amount of heating capability out of it as the garage only had electric and I thought it would be worth a shot to see if the mini with arctic heat pump could do the job before I mess with anything else.

I still need to insulate my 16 foot garage door that faces due west but the spray foam has already made it a much more usable space.

 

[yeldogt]

I noticed that immediately. I honestly believe that the heat pump is going to be working on my mini split WAY more than the reverse. The temp stays really consistent in there as it is. Not to mention the fact that A/C is far from our biggest concern in Duluth, but it's still nice to have.

I got the mini for humidity control and I'm hoping to get a decent amount of heating capability out of it as the garage only had electric and I thought it would be worth a shot to see if the mini with arctic heat pump could do the job before I mess with anything else.

I still need to insulate my 16 foot garage door that faces due west but the spray foam has already made it a much more usable space.

What people don't understand about a large open space is they really can be heated with a single point source. The key is air sealing -- and that is where foam excels. Most people don't have experience living in a tight space -- and heating or cooling a house with various rooms that each leak .... is different

 

[yeldogt]

I'm curious -- was different type of sheathing used in the building ?

 

[duluthUPLAND]

I'm curious -- was different type of sheathing used in the building ?

It was. Some kind of fiber board. Based on my conversation with one of the spray foam guys it would have been a cost savings versus the osb back in 1989 when the garage was built.

It seems to have held up fine for 30 years but it falls apart easily when you get after it. Hoping the foam should take care of that going forward.

 

[Nivekdodge]

I know I sound like a broken record but here’s proof. Top is attic,next is outside, my garage and the dining room

 

[yeldogt]

I know I sound like a broken record but here’s proof. Top is attic,next is outside, my garage and the dining room

It's all about leaks -- houses leak. Spray foam the full perimeter and you minimize the leaks and loss of conditioned air.

If you have the funds -- spray foam and variable speed HVAC equipment. You will save energy ... but, the real benefit is comfort. It's hard to quantify ... spray foam drops the heat/cool loads .. so you need smaller equipment. Smaller ductwork .... less velocity etc. There is savings on equipment and life time operating costs.

In the winter you appreciate the lack of drafts and stable temps in foam house -- with summer it's the lack of radiant gain. The radiant gain is particularly noticeable with cathedral ceilings and shed type roof structures -- like a cape cod type house built all over the east.

 

[jlv03]

It was. Some kind of fiber board. Based on my conversation with one of the spray foam guys it would have been a cost savings versus the osb back in 1989 when the garage was built.

It seems to have held up fine for 30 years but it falls apart easily when you get after it. Hoping the foam should take care of that going forward.

My old attached garage (torn down to replace with a slightly bigger one with a 2nd story addition) was built in 1995/6 and had the same fiber board stuff. The old garage was unfinished, so leaning a bicycle against the fiber board would punch holes in it and you could see the backside of the vinyl siding.

I felt extremely guilty tearing out a perfectly good garage floor, but shed no tears of saying goodbye to that fiber board stuff and 2x4 walls.

 

[brianpgriset]

Well I thought I'd post an update on the garage project since GJ members were so helpful in my decision making process.

I decided to have spray foam put in and I'm quite satisfied. I went with 2.5" in the walls and 3" on the roof deck.

I added 4 new windows and have the walls put up. Leaving the ceiling open for now but may finish at some point depending on heating an conditioning needs.

I'll be installing a mini split unit and building out a workspace and some dog kennels. Hopefully ready to move my home office out there by the end of the month.

Adding some pictures of the official "before", spray foam and new windows installed walls up.

Thanks again to the GJ community!

Question. You mention potentially adding a ceiling to clean up the look. How would you do this? You can't seal off the attic space and trap air, so the ceiling would have to be well vented to the attic space, right? What are the options to add a finished ceiling to a setup like this?

 

[kj_mustang]

Yes you can add the ceiling without any added vents to the attic space. If the roof and soffit area is sprayed with enough closed cell foam to prevent moisture and air migration to the inside of the attic and if you have a constantly conditioned space below the ceiling. There will be some air leakage to the attic from below the ceiling but it should be conditioned air so it doesn't matter. You can add small supply and returns to the attic if you want to. It just depends on your building setup, insulation, and type of hvac system.

 

[nadogail]

May you enjoy the fruits of your labors in good health.