spray foam TOO tight????

[oldgreen51]

I am planning a 40x50x16 steel building with spray foam insulation. The entire walls and ceiling will have drywall installed. Heating will be radiant floor heating. A/C is TBD...either central or none at all.

The shop will be used for antique auto restoration projects. I want to weld and paint in the shop as needed. Planning for 1-12'x12' overhead door, 1-10'x10' overhead and 2 walk-thru doors.

How do I deal with "fumes"...both welding fumes and paint fumes? It is my understanding that spray foaming seals the building VERY tight so I'm not sure how to ventilate well enough to remove the fumes . Opening the doors would "waste" the heat during winter operations.....suggestions?

Thanks in advance!!!

 

[Scott H in Wheaton]

Spray foam it, make it as tight as can be, and install a ventilation system to exchange air when you need it.

When you don't need ventilation you will maintain your shop temp just fine.

The way you word your question it sounds like you are expecting ventilation to come through cracks in the drywall.

 

[ripper70]

you could do this...It works great!!

 

[Thumper68]

If it is a big concern get a heat exchange unit, take cold outside air and warms it with the out-going inside air.

I built one for my old shop out of plywood, sheet metal, a duct fan and a filter by making a twisting passage that the outside air had to pass through.

 

[oldgreen51]

ripper70...that's looks interesting...did you build it yourself? more details please....!!

Thanks!

 

[Stuart in MN]

A ventilation system should be interlocked with an intake louver - when the fan starts a damper motor opens the louver, and when it shuts off the louver closes. You can get insulated louvers so that you aren't losing heat when the system's not in use.

 

[69supercj]

If your going to do a lot of painting I'd definitely consider a dedicated paint booth. Go to some auctions when a body shop or dealership closes down, you can usually get a VERY good deal on a used booth. Or make your own on the cheap. Buddy of mine just walled off a room in his shop and put an exhaust fan in one end and a roll up garage door on the other with filters in place of some of the panels. Works well and he turns out some absolutely killer paint jobs. As for the welding fumes, how much welding do you plan on doing? I can't imagine in a 2000 sq.ft. bldg. with 16 foot sidewalls that you would need a lot of ventilation.

 

[ripper70]

ripper70...that's looks interesting...did you build it yourself? more details please....!!

Thanks!

Yes i built the can and used an old fan out of a oil burning furnace. I built a sleeve that went through the wall with a stainless steel louver set up that opens and shuts as fan turns on. It ***** some serious air from the building.

Check out my build thread: http://garagejournal.com/forum/showthread.php?t=225559

 

[Lippyp]

I have an old cooker extraction hood I plan on repurposing for a small scale paint/grinding/welding area, handy as it also has lights built in and filters are dead cheap.

 

[floridafarmer]

My buddy just had his new garage (2x6 wood frame with metal siding) sprayed - he was really happy until he saw from the outside how it warped the metal siding...Might want to ask the installer if he thinks there is any risk of this.

 

[wssix99]

I am using a HRV (Heat Recovery Ventillator) in my garage, which will also be sealed with foam. (We want the foam to keep fumes out of the house and are using the HRV to keep the space able to support human life and to recover the heat being vented out with the fumes.)

I'll be running the HRV attached to the lighting system, so whenever someone is using the space, air will be moving.

 

[BADSIX]

I would go back in one of the corners and build a paint room. you can just frame it up with 2x4s and sheet rock it. make it 9' or 10' high and use the upper for storage. your sure not going to like doing any paint work with out it, you'll have paint over spray on everything. I do restorations and have a paint room, I couldn't live without it.
Jay D