48x39x14 shop build

[ultrarunner]

It's not a "no-no". The code requires specific fire safe vents that prevent embers from entering. We just went through this on our house which is in a fire prone area of California. We added ridge vents this summer while we were doing the roof... in fact the roof inspector said we had to have vents (they were planned anyhow).

Since you're in the city you may not be worried, but if I had older non fire safe vents I'd be replacing them with fire safe ones. A lot of recent research has shown that in wildfires many houses burn from the inside out because embers got in.


I'm eagerly following the venting discussion as I'm planning a shop. Humidity is a problem in the winter but as mentioned I also have wild fire safety to worry about.

The inspector was adamant the eve vents had to go and solid 2x blocking in it's place... the builder, owner and architect were unable to sway and I happened to be there as it went down...

Beautiful home on several city acres with tile roof and lead flashing...

2013 was the sign off date... maybe things have changed?

I had zero issues with my re-roof from shake to Presidential which required new sheathing... doubled the number of eve vents and installed ridge vents... Pulled a permit and the inspector did a drive-by... rolled down the window and said looks like a nice job and smart getting rid of the shake...

 

[ultrarunner]

What about off-gassing from the foam products?

Is spray foam and others affect indoor air quality?

Also..

I was visiting friends that had a nice roaring fire on Thanksgiving...

It was cold so the doors and windows were closed... someone burned the dinner rolls and the ducted range hood was turned on...

Glad I was not near the hearth because a wall of fire came right into the living room drawn by the range hood... this was a 1950's home with single pane windows and aluminum sliders...

 

[ovrszd]

Excellent discussion.

Thanks to everyone for contributing.

I notice an atmospheric difference in my new shop compared to my old shop. Old shop is all metal building with R19 walls and R30 roof, no attic. At a glance I contribute the difference to better window/doors. But can't confirm that. New shop seems tighter and quieter.

 

[murph1]

Richard I am really liking this build of yours. Was there any thought to put in the outlets first the put the walls up?

 

[RayfromTX]

What about off-gassing from the foam products?

Is spray foam and others affect indoor air quality?

Also..

I was visiting friends that had a nice roaring fire on Thanksgiving...

It was cold so the doors and windows were closed... someone burned the dinner rolls and the ducted range hood was turned on...

Glad I was not near the hearth because a wall of fire came right into the living room drawn by the range hood... this was a 1950's home with single pane windows and aluminum sliders...

Fireplaces need make up combustion air. In the old days this was supplied by the leaks in the enclosure but that meant that cold dry air was brought in from the perimeter and those rooms get colder. Most of us are familiar with the room with the fireplace being the only warm room in the house and this is part or most of the reason. Testing repeatedly shows that fireplaces can be a net loss of heat in a home. Many are ineffective at radiating their heat into the room but all of that roaring heated air that goes up the chimney is replaced from somewhere and that somewhere is cold. Makeup air should be introduced near or even in the fireplace. If it is introduced in the fireplace it must be designed to not interfere with draw or combustion or safety. My most successful builds have introduced it in front of the hearth but architecture often prevents that approach. A nearby window can work but the cold air sinks so a raised hearth and an open window can create a cold floor. Understand though that the other option is to have cold floors throughout the house due to infiltration created by the negative pressure induced by the fireplace.


Exhaust hoods create the same effect so large hoods now found in more expensive homes need the same thing. Each of these issues is a subject of it's own.

I sometimes use but don't prefer spray foam. It is possible to cause problems when applied if the mix is wrong or the surfaces are too cold or the tech is not properly trained. As it has become more popular, the level of installation quality has gone down. People have gotten into it for purely business reasons but not all have recognized the responsibility that comes with applying this product. In the early days the company owners were more passionate about the product and were well aware of the early failures and health issues. It is important to note that while properly installed spray foam is safe and while the gasses from the install are mostly benign there is a serious health risk to being present during application. The gasses that are produced are converted to formaldehyde in your lungs is my recollection from a class I took. Here is a link for further study. Vacate and Safe Re-Entry Time for Spray Polyurethane Foam Application | Safer Choice | US EPA

I prefer board foam insulation. It is safer and far less expensive and is much cleaner than spray foam. Continuously applied to the exterior it is easier to do an effective job than trying to insulate around headers, intersecting walls and other interior complications. I use spray foam only where I have to. On my current project I used 5 different insulation types but none of them were spray foam beyond what I used around doors and windows. I used high compression polyiso, medium compression polyiso, board form mineral fiber, extruded polystyrene and expanded polystyrene. Each has it's place.

When you get all of this stuff right it is amazing how well a building can perform. In a well designed building air distribution becomes much less critical and comfort is much easier to attain. Compare this to a car where on a warm day you must blow cold air directly on your skin to feel cool.

 

[ultrarunner]

The most comfortable winters I have experienced were in Austria... radiant heat is very common and used throughout the home with many zones... walking into a bathroom with a warm tile floor and heated towel bar doesn't get any better...

Plus the ancient ceramic tile ovens called Kachelofens found in living rooms provide warm dry heat without any of the problems of drawing in outside air as the fire box is often located in a utility space or backside of a wall...

It's been over 30 years now but the year I spent working construction there provided a wealth of practical experience...

These types of ovens were found in workshops along with radiant floor heat... very pleasant in sub zero temps... plus the heat source was often multi fueled... wood, heating oil, natural gas... etc.

 

[prichard]

I just saw this, Richard.

Looks great. I remember you discussing plans, etc. Glad to see you getting it done.

 

[ovrszd]

Richard I am really liking this build of yours. Was there any thought to put in the outlets first the put the walls up?

Thanks Murph, I prefer conduit for later changes. Things that I forget, etc.

 

[pinetree10]

In my area it's often discussed that a building can be too airtight. My HVAC guy doesn't recommend spray foam on the entire structure. He likes it on the walls to assist in air transfer. He doesn't recommend it on the roof for fear of being too tight. Says he has installed several dehumidifier systems in houses with spray foam on everything.

I can relate to that.

A few years ago I wanted to insulate and finish my 2 1/2 car attached and unheated garage so before I put the drywall up I caulked and spray foamed (a few cans from Home Depot) every crack, hole, and crevice that might leak air. The place was built in 1982 so there were some spots that needed sealing. Once that was all cured I stapled up faced insulation on all the walls and the ceiling. After I put up and finished all of the drywall I primed it twice and painted it twice, then installed a new fiberglass man door and a new insulated overhead door. I had no idea how effective my efforts would really be.

As the summer turned to winter and it got cold outside I noticed that the space would actually hold the heat from my truck's engine and my wife's SUV engine all night and if it got real cold outside I'd get condensation on the overhead door windows and the man door knob. I also noticed that when I opened the new man door to go outside, the room was so airtight that the whole overhead door would move slightly and make a noise where the seals around it were stuck in place. It's been a few years now and the only negative is I have to occasionally coat the screws on the door knob with a little oil so they don't rust. It is extremely airtight and I could see this same situation posing the problem you mentioned if the whole house was so airtight. I'm just happy my truck is warm when I go out to start it in the wintertime.

Thanks for posting all the pictures. It really is a beautiful building and very well built. Good luck with the house.

 

[ovrszd]

Thanks Gus.

Friend of mine built a shop and installed a louvered exhaust fan. Turn on the fan and the louvers will open about halfway. Open the walk in door and it speeds up and the louvers fully open. He's suggesting that I install a louvered vent at the opposite end to allow the exhaust fan to suck out the engine exhaust or welder smoke that I want to remove.

I am struggling with cutting a hole in my building for the exhaust fan. I'm really struggling with cutting a second hole to let in outside air.......