Hot garage is not cool!

[zuren]

I recently discovered the Garage Journal forum and have been lurking for bit. I am finally researching what I need to do to solve the heat problem in my garage.

As you can see in the picture, I have a deep, 2 car garage attached to the house. Here are some details:

• Location - located in southern MI
• Doors - Wayne Dalton with some level of insulation (I believe this is the model - http://www.wayne-dalton.com/classic-steel-garage-doors-9100-9600)
• Walls - NOT insulated, just studs
• Ceiling - None. Can see all the way to the roof through the trusses
• Venting - Ridge vent at peak of roof, continuous vented aluminum soffit
• Sun exposure - there is no shade; the doors in the pic are facing south, the east wall gets pounded by the sun in the morning, south face gets exposure all day

All summer, the garage gets excessively hot. As an example, today it is 83 degrees outside, partly cloudy, and breezy. In the garage with the doors closed, by 3pm it was 102 degrees. I do not have any other data points, but 20 degrees hotter than the outdoor air temp. seems about right. I would like to begin taking steps to help vent this extra heat.

I'm trying to sort out the order of improvements that give the best value. I would love to finish off the garage with insulated walls, insulated ceiling, and natural gas heater in one big project but I don't have that kind of budget or time. I'm looking for low cost, high impact solutions for now, and take on larger, more expensive steps in chunks. Some solutions I'm considering:

• Passive gable vents at both ends of the house (there is an opening at the top of the wall between the house attic and garage; gable vents at both ends might help establish a cross breeze the length of the house)
• Active gable vent (eg. a thermostat controlled fan)
• Insulate and wall only the south and east walls that receive the most sun (for now)
• Add vents low on the walls for added airflow
• Install the large window that I already have on the north wall, and leave it cracked (instead of, or in addition to, more vents) during the summer.

Installing passive gable vents up near the peak seems like a cheap first step but wanted to get feedback from the community before I start cutting holes in my siding.

Thanks!

 

[rattle_snake]

I would install a thru wall exhaust fan on a timer (or thermostat) near the ceiling, and an intake vent on an opposite wall.
This allows ventilation when building is secured, especially at night when it is cool outside.

You can insulate/enclose the ceiling later without making changes.

 

[kd3pc]

insulate the ceiling, the walls and use the baffles to make the most of your soffits and ridge vent.

fans will help, both interior and exhaust, but I would use the gable vents, as I hate cutting holes in a perfectly good roof.

 

[wade_660]

I have the same problem but in Georgia. I would second the gable vents and fan. Those two coupled with an insulated ceiling would probably make a big difference. I just spray foamed mine and it's twice as bad as before. I'm about to have to put air conditioning in it I'm afraid.


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[GYPSY400]

Gable vents will not be good with a Ridge vent.. either one or the other with the air entry point at the soffit.

If you want the best bang for the buck.. insulate the ceiling first.. thats more important than doing the walls

Sent from my SM-G903W using Tapatalk

 

[My Old Tools]

Insulate the ceiling. That is always the highest payback.

 

[Abeo]

After I insulated my walls and ceiling, my summer temperature went from 100+ to 70-75. This is in an area that doesn't go much above 80. Having the open rafters was what was causing the heat.

Bonus: the garage became much quieter.

 

[landlord30]

I'm guessing you freeze your *** off in the winter as well? I'd start by insulating the walls and ceiling. Buy the insulation a little at a time. I would think just doing that alone would make a difference. Once the insulation is up you can start buying a few sheets of wall/ceiling covering at a time and do this as time and money permit.

 

[xtremek]

The quickest and cheapest would be to put plastic on the bottom of the rafters and the walls. Then put insulation up as you can afford it starting with ceiling. Then I put the plastic back up. I hope to finish the insulation this year, and it's been 4 years in the doing.

 

[Bretny]

You can start off by venting the attic area and stapling up that .5r pink foam that comes in an acordian shape. Theu sell it at home depot. It will keep the heat on the roof out of your garage.

 

[Falcon67]

insulate the ceiling, the walls and use the baffles to make the most of your soffits and ridge vent.

Only way to go. I used TechShield decking and the underside runs average 120F in the summer. No way to vent that and have any cooling without a sealed ceiling and insulation.

 

[bcoke]

How about a powered roof event , **** out the hot air and it will be 20 degrees cooler [the 80 degrees from outside not the 102 degrees inside] fans will help with "wind chill". bobbycoke

 

[tlin]

With the underside of the roof exposed as it is (no garage ceiling), I'd recommend also putting up a radiant barrier as part of the insulation job since you've got such good access to everything (my $.02). Wishing I'd have known about that when we had our house built in 2004.

I recently installed one of these powered exhaust fans (a week ago). Easy install (if comfortable with electrical) and my garage is now at least consistently at ambient temp instead of being a cook box. Local company, got to chat with the inventor/owner when I picked it up so that was a nice bonus.

Good luck with your project(s)!

 

[SGDCharlotte]

I recently discovered the Garage Journal forum and have been lurking for bit. I am finally researching what I need to do to solve the heat problem in my garage.

As you can see in the picture, I have a deep, 2 car garage attached to the house. Here are some details:

• Location - located in southern MI
• Doors - Wayne Dalton with some level of insulation (I believe this is the model - http://www.wayne-dalton.com/classic-steel-garage-doors-9100-9600)
• Walls - NOT insulated, just studs
• Ceiling - None. Can see all the way to the roof through the trusses
• Venting - Ridge vent at peak of roof, continuous vented aluminum soffit
• Sun exposure - there is no shade; the doors in the pic are facing south, the east wall gets pounded by the sun in the morning, south face gets exposure all day

All summer, the garage gets excessively hot. As an example, today it is 83 degrees outside, partly cloudy, and breezy. In the garage with the doors closed, by 3pm it was 102 degrees. I do not have any other data points, but 20 degrees hotter than the outdoor air temp. seems about right. I would like to begin taking steps to help vent this extra heat.

I'm trying to sort out the order of improvements that give the best value. I would love to finish off the garage with insulated walls, insulated ceiling, and natural gas heater in one big project but I don't have that kind of budget or time. I'm looking for low cost, high impact solutions for now, and take on larger, more expensive steps in chunks. Some solutions I'm considering:

• Passive gable vents at both ends of the house (there is an opening at the top of the wall between the house attic and garage; gable vents at both ends might help establish a cross breeze the length of the house)
• Active gable vent (eg. a thermostat controlled fan)
• Insulate and wall only the south and east walls that receive the most sun (for now)
• Add vents low on the walls for added airflow
• Install the large window that I already have on the north wall, and leave it cracked (instead of, or in addition to, more vents) during the summer.

Installing passive gable vents up near the peak seems like a cheap first step but wanted to get feedback from the community before I start cutting holes in my siding.

Thanks!

Insulating your ceiling is the ticket. If it were me, I would probably put some sheetrock on the ceiling and have a blow truck come out.