Do insulate. It will slow the rate of temperature changes within the garage. My attached garage has no climate control equipment serving it. But the garage serves as a buffer to protect that insulated wall of my house from the outside weather. And the garage benefits from the influence of the house wall temperatures. The garage has never experienced freezing inside. The only drawback noted is that in Summer, the residual engine heat from automobile engines is trapped in the garage. In Winter, that heat is a benefit.

This post was edited by bus_driver on Tue, Oct 21, 14 at 8:18

We were told we definitely wanted to insulate our garage and so we did. It does make a difference in keeping the garage warmer during the coldest seasons...

Thanks. There's no question that the wall between house and garage will be insulated. I don't need the garage heated in the winter but also don't want it to be extra hot in the summer. It's a side load garage so we'll have two large windows we can open for ventilation.
My concern during the winter is that our laundry room plumbing is on the wall between the house and garage. Does insulating the rest of the garage walls, overhead door, and attic space really make much difference?

Would an insulated overhead door reduce the heat that is conducted in summer from the west afternoon sun or just trap it in better?

Insulating the garage will help some, especially against wide swings in temperature. Even uninsulated, our garage stays about 10-15 degrees warmer than outside. Here in SC, ours will probably never get below freezing once insulated.

It is very important to insulate the garage door. I used to have a machine shop, and the idiot landlord painted the metal, west-facing overhead door dark brown- in Florida! You couldn't even stand near it on a summer day. I jury-rigged some foam panels on the inside so that I could take them down when I needed to open the door, and it made all the difference in the world.

Put up a good, well-insulated door, and do basic insulation. Don't go overboard; you're not going to seal a garage very well anyway.

If you are dealing with both summer heat and winter cold, the moderation provided by insulating should be worth the cost. The issue of the washer being in the garage means that you also can't ever allow the garage to get below freezing because even though the plumbing in the walls would be protected, the water filled hoses would freeze and cause even a frost free hose bib to rupture. Putting electric heating tape on the hoses could guard against this; however, you would want to monitor it and disconnect the hoses from the wall in a power outage. If the garage is insulated, it's less likely that you'll have to worry about an issue like this. Based on the additional info, I say go ahead and insulate.

kudzu9 -- the washer is not actually IN the garage. It's inside the house, in the laundry room which is adjacent to the garage. That's why the plumbing for the washer would be in the wall between garage and house.

MushCreek and others - thanks for your input. I'm going to go with the insulated door and do some basic insulating, but as you said-- not go overboard.

Thanks!

Mushcreek: +1

Remember that buying a door already insulated gives you a far better operating door than adding insulation to an existing balanced door. The weight of that lightweight stuff adds up. Also get the door trim with the vinyl flap (or equivalent) instead of solid stop.

Wiseman- Sorry...I misread. That makes things easier, and I think you've got this figured out.

Agree with insulating in your situation but even better would be to build it completely detatched and not have to worry about the insulation or air quality concerns of breathing garage air in your home.

"---build it completely detatched--" That is one perspective and certainly to be considered if the idea appeals to you. But it definitely would not be my choice.
The extra exterior wall surfaces on both the house and the garage will involve more initial expense and possibly more ongoing maintenance expense. Plus an extra exterior door on both structures- to be locked and unlocked perhaps a few times per day.
Choose carefully.

I would expect detatched to be more in upfront costs, maybe more in ongoing maintenance costs, but what about health? Garages account for some of the nastiest sources of indoor air pollution.

By the time you average out not having to insulate, air seal, and fireproof, its possible to stay even in upfront costs in some situations. Knowing what I know about how garages can negatively effect Indoor Air Quality, I would gladly pay more to detatch if at all possible.

hhwiseman-our last home had the plumbing to the laundry room on the garage wall. That wall was insulated. It took years before we 'finished' off the garage and insulated the remaining walls - the door never was. Our pipes to the washer never froze. I would definitely do an insulated door. They do make a difference.

I don't quite understand the air quality issue with attached garages. You never leave your vehicle running in the garage with the door closed and seldom do you need to warm up your car much if it's parked in the garage so I guess I'm not sure what the issue is? Maybe I am naive but it's nothing I've given much thought to - detached garages are not at all common around here and I am in the midwest with strong winters.

I do like the look of houses that do not have a garage attached but the sacrifice of functionality with harsh winters would not be a trade off I would make. YMMV.

Autumn, most people arent aware of the problems. The Carbon Monoxide CO concern is probably the most dangerous introduced risk. That's great you point out that you shouldnt leave a car running with the door closed. Do you always allow the air to clear when you pull into the garage before closing the door? What about when you leave for the day? Do you sit in the driveway and wait for the air to clear before closing the garage door? What if there isnt much of a breeze that day?

Do people think that everyone is aware of the risks of trapping CO in the garage? Most CO poisoning cases go undiagnosed. It doesnt take a death to be very unhealthy.

What about a parked car with no CO? Benzene, toluene, xylene, formaldehyde, particle-bound polycyclic aromatic hydrocarbons (pPAH) and many volatile organic compounds (VOCs) are all up in the mix. Hot engines and leaking fluids are probably the worst offenders.

Then there are the many things people keep in garages that are terrible to share the air with. Lawnmowers, weedeaters, gas cans, paints, solvents, cleaners, dust, pesticides, herbicides and other chemicals. The more attached the garage, the more your interior air is garage air.

A little bit of thread drift here, but I've wondered about clearing out the air in the garage. I was thinking of installing an exhaust fan on a timer linked to the garage door opener, so that any time the garage door was operated, the exhaust fan would run for X amount of minutes. Although the house will have the required CO detector, as you pointed out, there are plenty of other pollutants.

As for detached garages- believe it or not, in some communities they are not allowed.

brian-thanks for the education. I had not thought about clearing the air after parking before closing the garage door. I would say in the spring summer fall we do get the air cleared as the door is normally left open until the end of the day. As for winter though - we'd have snow piled up so it's closed immediately. Even then sometimes it's blowing hard enough the door sensor catches it and it will continue to open when it gets down to the sensor. So the VOC's actually seep in through the door seal between the house and garage or it's passes in from opening/closing it?

As to mushcreeks point - I know some places around your garage must be attached and you may NOT leave the door open. Crazy.

Indeed, you MUST poison your family. Well thats certainly better than hurting neighbors property values, right?

I think the bigger problem is leaving for the day. Its easier to air it out when you get home because you are there to remember to close the door. 99.999% of people dont take the time to do it when leaving. Allow me to stress that CO is only one of MANY sources of indoor air pollution from attached garages.

Mush is correct in the best practice of mitigating but I dont see this as thread drift at all. Insulation is a waste of money if you are not paying attention to air-sealing at the same time so you are coupling the garage air to the home air more when you insulate. Given the current state of air-sealing for most construction in the US (pathetic) there are plenty of ways for garage air to mingle with house air.

If youre building to the current 2012 codes (everyone should be IMO), you should be following ASHRAE 62.2 which includes provisions for garage exhaust. I believe it requires a 100CFM fan but since Ive always been able talk clients out of an attached garage, Ive never gone too deep into control requirements. Iam sure I will eventually and think automatic controls tied to the opener is the best route on top of OCD levels of air sealing between garage and house. The house/garage door is an obvious location but I would guess most leakage occurs between the masonry and mudsill. Homes that operate under negative pressure or where the car garage door faces the prevailing winds are under increased risks.

ASHRAE 62.2 which includes provisions for garage exhaust

The 2010 Addendum to 62.2 relating to garage exhaust fans does not apply to single family houses. Though not a bad idea when so many people use the spaces for everything from barbecues (!) to furniture refinishing.

The only time I've insulated a garage is when I intended to use it in the winter working on my vehicles. Pushing the temperature above 0ÃÂ C. feels like a heat wave in January-February.