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.......

 

[prichard]

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.......

Why not do like he did and just open man door or slightly raise overhead?

 

[ovrszd]

Why not do like he did and just open man door or slightly raise overhead?

Because it does nothing to ventilate the building unless a second opening is introduced.

I am hoping my heat source will make the exhaust fan more useful.

 

[prichard]

Yes, sorry I wasn't clear. I was only referring to the second opening.

 

[kevinwak]

Somewhere deep down on my to do list is to install a bathroom exhaust fan in my garage. I want just a low volume unit to run continuously to pull out the moisture from snow melting off of the wife’s van.

 

[ovrszd]

Somewhere deep down on my to do list is to install a bathroom exhaust fan in my garage. I want just a low volume unit to run continuously to pull out the moisture from snow melting off of the wife’s van.

Isn't this just like life? We improve the efficiency quality of our building and in the process create a problem.

 

[kevinwak]

Isn't this just like life? We improve the efficiency quality of our building and in the process create a problem.

Yupp.

 

[RayfromTX]

The new problem is created when the approach to the original problem doesn't address all the factors at play and/or is based on incomplete understanding of the issues. Even a tent has a potential for condensation issues. Remember not touching the ceiling if you didn't want a drip to start coming down on you? That's because you were introducing a surfactant from your skin to a surface that was wet from your breathing. The tent isn't the problem.

Tight buildings are able to perform at a much higher level but moisture must be understood and managed. This is worthwhile for living space but may be overkill for shop space. If you want shop space that performs like living space then you just have to build it tight and use proper levels of insulation placed in the right location for the system you are using. Then you can control the moisture levels with mechanical ventilation and/or dehumidification depending on your climate and circumstance. Dehumidification is required in the gulf coast region but mechanical ventilation is adequate in Colorado.

We used to build houses from wood without insulation. They leaked at the windows and in other places but they dried out quickly enough that they didn't rot. When insulation is added the drying potential is greatly reduced and now the leaks created rot. The leaks are the problem, not the insulation. Air tightness is the same. The moisture control is the problem not the air tightness. You can choose your level of performance but if you don't understand the science, you may make bad choices about how you utilize the products and components at your disposal. High performance buildings are a pleasure just like high performance cars but they require knowledge to build them safely.

A house doesn't have to breathe. Moisture has to be managed. Managing moisture by building a leaky building is akin to building a slow, poorly performing car because it is safer. That may be the right decision for some but the statement is not correct. You can't build a building too tight with our technologies but you can create a need for improved water vapor management.

In the 30s they solved the problem of moisture in buildings by ventilating the attic to allow it to escape. It was a solution that was appropriate to the time. Buildings were leaky and uninsulated or poorly insulated. That ventilation also allowed lots of heat to escape and created buildings that were often too dry. People then added humidifiers to control the moisture in the air. 80 years later there are much better solutions to these issues but they require us to look at things in a slightly different way. You can live in a tent or a refrigerator but the real solution isn't something half way in between.

The best ideas come from starting with the second law of thermodynamics and an understanding of the water molecule and applying those principles to our buildings. That sounds kind of crazy but that is the reality of building high performance buildings and it is no different than the solutions from the 30s. ASHRAE used the second law and an understanding of water vapor and developed testing in Minnesota that showed that the introduction of one square foot of attic ventilation for every 300 square feet of roof area would prevent the dangerous accumulation of water in the buildings of that era. We are still doing the same thing but consumers will need to catch up once again.

Beware of getting your info from marketing materials or insulation or HVAC contractors. Contractors are often well meaning but lack an understanding of the real issues and are influenced too heavily by marketing.

 

[ovrszd]

I appreciate your time in this discussion. I hope you appreciate that your input is beyond my capability to fully cprehend. I think this is common in society. So society is left to make their decision based on economics. Sad, but true. So to reach us you must include economics in your offerings.

Thank you very much for your input in this discussion. I'm learning, although slowly.

 

[RayfromTX]

Richard
I understand. It took me a year of full time study to get a background knowledge of the issues and then a 6 hour lecture by one of the top building science professors of our time to congeal it into gut level understanding. I then spent a year developing the ways to overcome the challenges with cost effective strategies and about another 2-3 years before all my buildings were transitioned to the new system. I refused to implement any methods that were not economically viable even though the budgets of my buildings could sustain methods that are not able to be strictly economically justified. As I have said before, this is a big subject and it can't really be covered in posts on a tractor forum but I will say this;

2" polyisocyanurate foam board which is one of the exterior insulations I use is around 65 cents per square foot. That is more than fiberglass but less than spray foam. As a part of an overall system, it can be done for a very reasonable cost. The measures we currently use to air tighten and insulate buildings are mostly a hodge podge of whackamole where we address each problem that is created by applying one more layer of sealing technique or strategy. The things I no longer need to pay for on my buildings include, sealing at the plate line, sealing wire penetrations, weatherstripping and insulating attic access, IC rated recessed cans, sealing recessed cans to the drywall, sealing and gasketing electrical boxes, attic ventilation and other things. The biggest benefit however is that there is no safer way to build a building from a durability and indoor air quality standpoint and the cost of no failures can't be overstated.

But I get it. There is a lot of new info to digest and it takes time. Just take your time and if you are interested dig a little deeper as time allows. What matters isn't knowing what product to use where. What matters is to understand the forces at play and how they affect our buildings. After that, the rest becomes clear. I must admit that I would have gotten to a better understanding sooner if I had ignored products and strategies when I first started trying to learn about this and focused on the basic science instead. The implications of the Second Law are the key. Enjoy the journey.

 

[ovrszd]

Thanks Ray.

I think comsumers are swamped with advertising gimickery
Then add the builder's familiarity with a method he's comfortable with. The end result varies and further confuses the consumer.