Garage workshop
 

We recently moved from PA to the warm and sunny NC, and I am glad that we finally found a house that we will be moving in to sometime in the next 30-40 days. Since it is difficult to find homes with basements in this part of the country, I had to find one that would allow me to have a workshop, and this one does since it has a standalone garage that is separate from the others. It'll be cozy compared to my unfinished basement in the old house, but I'll make it work!

I'll have some work to set it up as a shop, and one of the first things would be to HVAC it, and therein lies my question: while I am not certain, I assume it is unlikely that the garage is insulated and since it is already finished, I am not sure how to insulate the outside walls. I figure the ceiling would be easy since there is an attic above it, but not quite sure if there is an easy way to insulate the walls. My immediate thought would be to somehow inject expandable foam through a number of holes in the walls, but not sure if this is possible or there is a better way.

Any thoughts?

RE: Garage workshop
 

Check the yellow pages for insulation contractors and give them a call. Most of them are familiar with the method you speak of.

RE: Garage workshop
 

Awesome, thanks. I seem to remember having read somewhere about foam insulation being a pain to work with and even not recommended. Not sure where I read it but this is what had stuck with me. I'll look them up.

RE: Garage workshop
 

I remember we insulated the house I grew up in with blown insulation. Preferably in the process of residing it. You drill holes in the outer side and blow in the insulation. And of course, if you have fire stops in the wall, you have to be sure to get above and below them.


Tom

RE: Garage workshop
 

How are the exterior walls build up, from exterior to interior finishes?
What are the dimensions of the garage?
Glass windows? How big? How many? Orientation? Overhang?

RE: Garage workshop
 

Welcome ppkk. I did the same thing last July from living in Ohio all my life. I got tired of the cold & snow. Not too much of either down here. It does get warn at mid-day, but thats ok with me. Where in N.C. did you buy? I'm in Rockwell, which is N.W. of concord. Good luck on the move. Bill

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MILDBILL - thanks, we bought in the Mooresville area, down Brawley School Road so we'll be putting up with traffic until they widen the road. I won't see myself having time to fly any time soon, but at some point I'll need to find a good club, so I'd welcome any suggestions.

LNEWQBAN - certainly good questions, some of which I have answers to and others I'll need to answer when I move in and can examine things a little closer. For now, dimensions are about 10' x 20', with 3 outside walls, one with the garage door. Exterior is siding, interior is finished/painted sheet rock. One window, say about 3' x 4'.

RE: Garage workshop
 

If the interior is drywalled, there's a good chance the walls are insulated. Just cut a small (4"x4") hole in the drywall and see if there is insulation. Could save you a lot of work.

RE: Garage workshop
 

The garage door is your big killer.

Uninsulated walls isolate much better than a bare metal big door, specially if it has other orientation than North.

Trying to isolate the garage door would be my first step.

After doing that, not touching the finished walls, I estimate around 0.50 to 0.75 Ton would suffice, depending on the orientation of the three walls, door and window, as well as other heat generating equipment in your garage-workshop.
Door or window facing South and big water heater inside may need as much as 1.0 Ton.

You can use one window unit or one mini-split system like Sanyo or Mitsubishi, installed as high as possible in the room.

You can PM me for a more accurate calculation when you move in and can measure things better.

Regards!

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Retracted, didn't fully read original post.

RE: Garage workshop
 

Scott - while this is also my hope, somehow I doubt it that the builder would have insulated the garage unless it was sepcifically requested & paid for by the original owner. The house is only a few years old, and I may just call the builder to see if he can look in his paperwork and let me know whether this is the case.

LNEWQBAN - I agree about the garage door, not only do I need to insulate the back of it, I'll need to somehow insulate the sides (where the rails are) to stop draft from getting in. I am sure there are products that are specifically designed for that, I just need to search for them. Thanks for the offer to do the math, when I move in and get settled I'll take you up on that offer.

RE: Garage workshop
 

Do you plan to still open and close the garage door? For many years here in Floridawe haveinserted insulation or foamin the open slots of the frame and used cardboard andfoil tapeto hold it in. Home Depot sells garage door sealing strips for all four sides of the door, they work great. We use our garage for recording/band practice so the insulation/cardboard also works good for sound proofing...lol
We use a window unit, a couple fans and still use the garage door from time to time with no probs.
http://www.rcuniverse.com/forum/js/f...sn/biggrin.gif

RE: Garage workshop
 

not sure about the const. regs in NC but in CA if a wall is exposed to the outside then it needs to be insulated,
if its a newer building then I would think it should have insulation, the only area I have worked in that didn't require insulation in there const was HI and that was in the mid 80's it may have changed there as well.

like others have posted its easy to add blown insulation installed in your house/ garage, more likely than not it would be done from the inside of a garage,a contractor drills small holes, ubove,and below, the fire blocks,at the top of the framing bay, the blocking is nailed in at 48" up a wall its standard framing practices, then the holes get patched when the bays are filled with fluffy insulation simple as that.

simple test tap on the wall if there is a resounding drum like sound they may be hollow, if there is a dull thump then they have some form of insulation.

also the town should have a record of the plans, and construction permits on file, in many cases these records go back many decades so for a fairly new house there easy to find and should be on micro film, the construction inspection records should tell you the whats, and where's

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I wouldn't cut such a big hole,, A 1/4" twist bit will do the same job, it will grab and fiberglass insulation that might be in there,,

As said, Blown in can be done from either side,, patching drywall is much easier than exterior siding and you're not cutting into your vapor barrier

I just use a window unit in my garage,, up here I only us it a few days each year,, I can see you needing it more down there


Bigtim,,
I very rarely see the mid-span blocking back here as much as I did in when I was a framer in So Cal,,, it was always normal practice in older CA/Stucco construction.
Here just about everything is OSB/Vinyl siding,, blocking is just between floors/ceiling/attic spaces. A lot of slightly different construction techniques here

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Jumping ahead of the game. Your inteiror finish. With your drywall, a suggestion. Finish taping and "mudding",sanding and sanding. Prime and at least a couple of coats of "refrigerator white" paint, semi gloss. Install plenty of flourescent lighting, I've installed "high output" 8 foot flouresencent lighting in my shop and with our Northwest cloudy days etc. It really helps for lighting for our overall needs in the hobby.

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Do have a question, suggestion, whatever.

How big is the garage and how much space do you actually need? If you say, everything, then my suggestion dies.

What I'm thinking is that you could build a room within the garage and run the HVAC on that alone. You'd probably have to put in an insulated subfloor (membrane, 1/2-inch foam, subfloor and lino on top) and may have to insulate walls and ceiling with appropriate levels of sheet foam and new drywall as required.

Saves on having to close off all the leaks in the garage, minimizes what you'll be paying to heat or cool the whole garage, reduces noise for everyone else, and you don't have to worry about who left the garage door open.

Downsides would be that you may need a building permit (check with the building permit people to see what you have to do or don't need a permit for part of their job is making sure that your ideas will fly before you start building), reduced size in the garage can't spread by osmosis, more complicated space/parking considerations, something for the drivers to aim for when putting things away in the garage.

Thnking about the building permits people, even if you're converting the whole garage, they may know who has done similar conversions and might be able to show you what they'd done (subject to privacy limitations).

Asking around the neighbourhood may yield some answers.

This is a long-term project so no need to absolutely rush into it immediately on arrival. Take over the basement first and then expand into the garage.

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If you do find that there is no insulation and need to cut holes to blow in some here is what has worked for me. I just cut a circle out of a piece of plywood about six inches across and use that as a pattern to mark the holes to be cut on the wall. Then take a jig saw and turn it to a forty five degree angle and cut out your circles. It would be a good ideal to number them so you know which hole they come from. After blowing in the insulation just take the drywall circles that you cut out and put them back in the holes you cut them from. You will need to bed the holes with drywall compound and then stick the circles in. After that all you have to do is tape over the holes, sand and paint. Its real simple and a hole lot easier than measuring each hole to patch the drywall back.

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Alright, the home inspection was yesterday so I got a chance to take a closer look at the garage, albeit quite brief, and here are some more details:

- Dimensions are about 12' x 24'. Not too big but very workable
- None of the outside walls are insulated (basis the fact that the ceiling is not insulated from visual inspection by the inspector through the attic). If the ceiling is not insulated there is no way the outside walls are, and the inspector confirmed that local codes do not require the garage walls to be.
- There is a fair size window in it, and being from the North East (and originally Canada), I automatically assumed the glass would be double pane, so I didn't look closely enough, let's hope it's the case
- Didn't have a chance to look at the orientation, should show up on the plans when I get them

The first thing I'll do is epoxy the floor before everything gets moved in. More to follow...

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Not sure why the first picture shrunk, but here it is again.

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ppkk

There is a Hobby Town over on 150 (I think it's 150. The main drag through town) in a shopping center across the road from the Lowe's. Been in there several times when making sells calls in Mooresville. They should be able to lead you in the right direction as far as the club. I have even heard them talk about indoor flying when it does get a little cold around here. Welcome to NC and I hope that you are ready for some hot weather. Flew last Sunday afternoon after 4PM and still didn't have a dry stitch of clothing on me by 7:30.

Newton

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Correction: I spoke with the builder and all walls are indeed insulated. Only the ceiling is not, which actually works out because it would make wiring work for the installation of lights a little easier from the attic, I can insulate it myself after the wiring is done with minimal work. The garage door is also the insulated type so it looks like this thing is going to be easier than I had envisaged [8D]

The only question is, do I get a mini-split system as LNEWQBAN had proposed, or do I simply tie into the existing HVAC system in the house which is easily done from the attic... I like the latter better for obvious reasons, but if I do that I wouldn't install a return as it would be safety hazard (someone at some point could leave a running car in the garage). Not sure how well a vent without a return would work in a (fairly well) sealed room. We could argue that a garage is not very well sealed, which I agree, but to have positive pressure in the garage with air escaping, there would have to be negative pressure in the house to make up the lost air flow. Not sure how that would work with a home HVAC system, if anyone with this kind of background could chime in with some ideas that would be great.

********nut - thanks, I'll check it out when I get settled.

RE: Garage workshop
 

On your HVAC. Here's one suggestion. What ever you put in, you have to take out ! Meaning whether cooling or heat you need to allow for exiisting "air" to circulate. Much like building a cowling for one of our models. heat being generated by the engine, and allow "heated" air around the engine to escape to the outside. Likewise using your cars airconditoning/heater appication, you "crack" a window to rapidly exhaust the heated air out quickly to allow the cool conditioned air work in your "HOT" car if your using the "cooling" side of the HVAC.

Also, IF you go the existing HVAC system make sure it is big enough (tonnage wise) to support the additional square footage of the shop, without laboring the original system. Good point on your "return" air application. Most likely you would have to "crack" a window, or let the "conditioned" air/heat seep our through the various areas, doors, windows, garage doors, etc.

It sounds like with what info you've given you may be better off to have a seperate wall mounted A/C / heating system installed. Maybe one like the motels use, aka... the window mounted HVAC unit, where by in one swoop you have ac, heating and fresh/return air.
Your only concern is, can your house elecrical panel support the additional amps, where the panel is located, and where you want to run the wiring, etc.

Just some ideas for you to ponder. :)

RE: Garage workshop
 

Most state codes prohibit central AC for garages, for the reason you mention.

You will need to withdraw around 200 cfm from the central system, if you can insulate the ceiling.
The house needs to intake outside air make up for that non-returned volume.

If your air handling has a fresh air intake, there is no problem.

If not (99% of residential AC have none), you will not get 200 to feed the garage.
Doors can leak in as much as 10 cfm.
Toilets' exhaust fans and drier vent can leak in more when not working.
Each toilet exhaust fan will exhaust around 50 cfm, while working against your garage.

Results:
There would be less AC for the house.
The area will be conditioned even if you are not using it, but you will pay for the used electricity (unless you install a damper to block the garage supply at will).
Humid air infiltrating the house, which will be constantly negative, thru doors and walls (from the attic via power outlets).
Fumes from the garage (from glue oddors to car exhaust) will infiltrate the house.
Mold inside walls will develop with time.

Any mini-split is more expensive than any window shaker.
I would insulate the ceiling, seal the garage door, and install a 9,000 BTUH window unit in the window (or 12,000 BTUH if garage door or window is facing South and big water heater is inside the garage).

For better air distribution and less noise inside the garage, I would install a mini-split of similar capacity.

RE: Garage workshop
 

LNEWQBAN - thanks for the reponse, you convinced me, I am more comfortable with a mini-split for all the reasons you mentioned. I need to do a little more research on these systems but I thought I read somewhere that these also act as a heat pump (or can, maybe an option?) for the winter months. If so, that would hit two birds with one stone.

The only thing that I do not fully understand in your explanation is your comment above:

"Mold inside walls will develop with time."

Why is that?

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About mold:
Well, it is a very common thing here in Florida.

Mold grows having water and food, .......and it grows and expands like crazy, being the millions of spores that the thing shoots into the air what causes respiratory and allergic problems to people.

It can find food in the paper covering sheetrock.
The water comes from condensation of humidity in the air over sheetrock.
That condensation does not need to be visible to feed the mold, microscopic droplets are enough.

Humid air that contacts cool surfaces may reach the dew point.
Hot air can contain much water (in vapor form) than cold air.
That is the reason for which hair dries heat the air, and for which the evaporator of an air conditioner produces condensate.

This is a problem related to conditioned spaces, the cooler the place, the worst the condensation if humid air infiltrates.

In summary, humid air must be isolated from cooled spaces.
Positively pressurized buildings are the safest cure for that.
The second line of defense is isolation of walls from the open atmosphere.

Normally, interior walls are cold and full of humid air (when they are open to ventilated attics).
Is there where the mold grows unseen.

About air conditioning:
Window units come with cooling and electrical heating.
Mini-split units come as cooling only or cooling-heating.
The second type needs to be a heat pump (more expensive), which is supposed to use less electricty than an electrical heater.
The condensing unit is small enough to be installed either on grade or hanging from an exterior wall.

See attachement.

RE: Garage workshop
 

Thanks for the detailed response, and sorry that I didn't clearly explain my question: I understand the mold issue and what causes it, but I thought you were suggesting the mold growth would be a problem with the central air idea only and not with the semi-split (because the garage would be cooled all the time with central air, but I wanted to double check.) Either way, it is quite clear now. I actually hadn't thought about the problem caused when interior walls are ventilated through the attic, this makes a lot of sense!

Update to follow after I make more progress with this project.

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You are welcome, and best luck.:)

RE: Garage workshop
 

OK folks, we are all moved in and mostly unpacked and settled in, so I am starting to think about the garage (aka workshop) again. I epoxied both garage floors (there is also a two-car garage that will serve as a, well, garage) and it looks awesome. A lot of work, especially when doing it in 95+ degree weather and high humidity, but definitely worth it.

I am still going to put a semi-split in, but first I need to address the lighting and I need some input in terms of number and size of lights. The garage is 12' x 24' and the ceilings are 11' high. The walls are painted in a light color and the ceiling is painted white. I am planning on hanging a fixture over the build table for extra lighting.

I would appreciate any suggestions on the number and size of fixtures to install on the ceiling.

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Go T8 lighting, add as required. These give out far better and brighter light in a 4' light than a normal 8' fixture.

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PPKK, Welcome to NC! I too moved from Pottstown Pa. roughly 10 years ago, to Wilson NC, & was faced with the same issues with the garage. I ended up putting in a window unit for the A/C & a small electric space heater to keep the shop above 50 deg in the winter. My shop is seperated from my garage door area by a seperate room with a door on it . I still miss building in the basement during the winter months though. Hope everything works out for you.......Gene

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Gene,

Thanks. There were advantages in building in the basement, namely tons of available room to move around... but it'll be great to be able just open the garage door and move a few feet to do sanding and messy work so I am looking forward to it.

The mini-split I am looking at also has a heat pump so winter heating shouldn't be a problem. Another option is a portable A/C unit with heat pump built in, still deciding on that...

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Any suggestions as to how many T8 fixtures I would need?

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Add as required untill you have to wear sunglasses then unplug one. :D

Seriously though you'll have to add as many as you need. One directly over the work benches is great and you can fill the outter edges as needed. They throw out a good bit of light. One of these has more usefull light than a normal 8' twin bulb fixture. These are not a "dull" light like the 8' . It's really crisp.

We have 10 8' twin tube lights in our transmission building room (20x40 10' ceilings) and we still had to use flash lights at times to see our work well. I added a single T8 fixture over each build bench and now we have plenty of usefull light.

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A recent article in MA magazine by Bob Hunt suggested tons of illumination.

This old thread has some ideas:

http://www.rcuniverse.com/forum/m_29.../tm.htm#298687

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Illumination is good, but don't count out good old fashioned sunlight - it will show balsa 'dips' much better than artificial light!

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Good thing I have two large windows in there ;).