Recommendations/experiences with spray foam for existing shop

[paulsharvey]

Another thought; the "livable" part, your already framing; why not go conventional insulation on that part, just plain old R-11, and gap sealer in cans?

On the Shop part, if you plan to frame interior walls; maybe conventional is the best bet

 

[CliffordK]

I'll also paint any of the exposed foam in the shop side.

What about fire resistance?

I don't have foam... yet, but I have been doing research. Fire resistance is supposed to be reasonably good.

There is supposed to be an "Intumescent Fire Resistant Coating" that can be applied to exposed surfaces. I think it burns at least some, then creates an impermeable layer. On the metal side, fire requires oxygen of which there isn't any, and thus it can add resistance to external fires.

 

[CH4Ohio]

CH4Ohio,
What thickness did you do?

2" closed cell. As mentioned by others, the first 1" seals completely and eliminates air flow through the walls. That's the biggest benefit. But going ahead and spraying 2" makes sense and certainly doesn't double the cost.

 

[gsganzer]

Another thought; the "livable" part, your already framing; why not go conventional insulation on that part, just plain old R-11, and gap sealer in cans?

On the Shop part, if you plan to frame interior walls; maybe conventional is the best bet

Yes. Livable part that's getting framed may just get 1". Heck, the entire place may just get 1" after my research. I'm not trying to make the place livable, just workable. Working an uninsulated shop in the TX heat undoable.

 

[eolesen]

We are doing spray foam on our house under construction. There's a vapor barrier between the roof metal and the foam, and on the vertical panels and the sheathing. Had we done the shop, it would have also had a Tyvek-like vapor barrier.

Should you ever need to replace a panel, you'll want that barrier there foam fused to the panels.

In the habitable part of the shop I'll be doing standard batts in a 2x4 stud wall.

 

[WinterDeere]

I had my shop, which is built into a 1770's carriage barn, spray foam insulated. Like @Snobdds and others have already said or alluded, the big advantage of spray foam over others is the air sealing and inherent vapor barrier.

Prices will vary enormously, like 3 to 1, so get several quotes. I hired the cheapest bidder, because heck... it's just a barn, but the guy did a fantastic job, spraying everything 20% - 30% thicker than quoted and making really neat work of everything.

If you can provide on-site power (~100 amps to run those trucks) and do a lot of the prep work yourself, it will save you a lot of cost.

 

[paulsharvey]

So, im coming up with a very fast, rough, 2800 sq ft of wall and roof area. It could be as low as $2.50-3/ sq ft per inch, but upto $9/board foot.

So, im thinking a min of $8,500; on upto $25,900. I have seen some people report as low as $1.50/bf; or $4320; but i doubt thats the price a homeowner will ever see.

If its much higher than $7500, I would seriously look at a kit. Kraken has a fire rated, 1900 sq ft kit, at $2999.

 

[Snobdds]

We are doing spray foam on our house under construction. There's a vapor barrier between the roof metal and the foam, and on the vertical panels and the sheathing. Had we done the shop, it would have also had a Tyvek-like vapor barrier.

Should you ever need to replace a panel, you'll want that barrier there foam fused to the panels.

In the habitable part of the shop I'll be doing standard batts in a 2x4 stud wall.

This is very important to keep in mind. If I had to do it again, I would do it somewhat similar.

 

[paulsharvey]

As much as everyone wants spray foam; rigid foam, and then cans for joints is much more cost effective; IF the framing is in such a way it works out to be an easy install. Now, rigid foam, 3", might be $1-1.50/sq ft (not BF), BUT its not fire retardant, and it needs attached to something, And joints, and all need sealed too


Guess my point is, in my world, $9k is an awful lot of cash for shop insulation

 

[dieselscout80]

As much as everyone wants spray foam; rigid foam, and then cans for joints is much more cost effective; IF the framing is in such a way it works out to be an easy install. Now, rigid foam, 3", might be $1-1.50/sq ft (not BF), BUT its not fire retardant, and it needs attached to something, And joints, and all need sealed too


Guess my point is, in my world, $9k is an awful lot of cash for shop insulation

That’s a good point.

My question is the loss of a 4’x8’ sheet when being fit into a 5’ trusses openings.

Would it work to combine the cutoff pieces to make another 5’ piece?