Insulate my garage- will it help?
I just added a floor on the top of my garage to make an addition to my master bedroom. Everything is great except that the new master bedroom stays about 2 or 3 degrees cooler than the rest of the house on that level in winter. I guess this is natural because the garage is uninsulated and exposed on three sides to the elements, but I wonder if having insulation blown into the walls of the garage would help. It is two by four construction with cedar siding and no insulation at all behind the drywall. When we built the addition we used two by six’s and R30 insulation. We also had an entirely new heat pump installed and the installer insists that the calculations were correct but that it is normal for the new room to be colder.
Is the garage heated? If not, I don't think insulating the walls of the garage will do any good. The insulation serves to minimize heat loss (or gain) through a wall when a temperature differential exists from one side of the wall to the other. If the garage isn't heated, there's no temperature differential and I don't think insulation is going to help. Is the floor of the addition insulated? That would make a big difference.
I'd be interested to hear why the heating contractor says it's "normal" for the new room to be cooler. The unheated garage space underneath the addition should have been (and maybe it was) taken into account. If you have forced hot air delivery to the rooms in your house, is there a balancing damper to the addition that you can open up a little more?
Hope this helps.
Edited 3/11/2003 5:47:47 PM ET by stonebm
Edited 3/11/2003 5:49:33 PM ET by stonebm
Stonebm, Thanks for your response. In answer to your questions, no the garage isn't heated, yes I insulated the floor of the addition with R30, and no, there was no damper installed in the new heat pump(I asked, but the only ducting they used was flexible tubes so there was no way to put in a damper). Even though there isn't a damper, I closed off two of the three registers in my attic for the winter which increased the airflow to the other parts of the house.
My heating contractor says that there is no way you can compensate entirely for the fact that the addition is above an unheated garage and the high ceilings(I forgot to tell you that I put a tray ceiling in the addition with 12.5 foot height) and the effect of being exposed on three sides to the elements, while the other heated rooms are exposed at the most on one wall.
Anyway, it looks like we'll have to deal with it as it is.
I don't know, my mst bedrm is over the garage, and the heat is balanced with the rest of the house. Same deal, unheated garage, high ceilings.
It sounds like you need a second opinion.
Is there insulation between the floor of the bedroom and the garage?
Can't say for sure that insulating the garage will make the room above warmer. But there might be some value in it for the garage itself.
Insulating a garage will help with some of the temperature swings. It won't be quite as cold on a winter morning, or as hot on a summer afternoon. And you can put a heater in it and warm things up a bit if you're changing the oil in your car or something when it's cold. Might be worth thinking about for those reasons alone.
As fot the master bedroom being colder than the rest of the house - I'm with the other guys who say that's B.S.
You know why the French don't want to bomb Saddam Hussein? Because he hates America, he loves mistresses and wears a beret. People, he is French. [Conan O'Brien]
only two possibilities.. the heating equip. is undersized ( or the ductwork)...
you just don't have enough insulation.. did you say R-30 in a 2x6 wall ?..
if i do a room over a garage.. i want 2x10, with dens-pak cellulose and 1 " foam on the ceiling below..that would be a true R-30..
also.. how did you insulate your trayed ceiling ?.. our attic would be about an R-60
and what about the windows.. what style are they .. what r-value .. how big ?
what do you have for your wall insulation ?
Mike Smith Rhode Island : Design / Build / Repair / Restore
Edited 3/11/2003 11:35:27 PM ET by Mike Smith
Sorry, I made a mistake, it was 2x6 walls with R19, and 12" floor joists with R30, and the ceiling is 2x8 with R30 also. I think these were the recommended values for my area (Washington DC area).
I have 3 windows in the addition, one large Palladian and two other standard size. They are Pella casement windows and the total area is about 70 square ft. The addition is 14'x20.5', but with the old master bedroom factored in, the square footage is 400'.
I have hardwood floors in the addition over 2 layers of 3/4" OSB, but the still feel quite chilly getting out of bed in the middle of the night, so I assume that is where most of the chill is coming from. That's why I wondered about insulating the garage walls to keep the temperature in there more stable. When it is sunny the addition and the garage get a lot of sun and warm up quickly.
I would suggest furring the garage ceiling, install at least 1" foam sheathing, and drywall again. I think the convection is pulling the cold from below.
Excellent idea, I actually have several holes in the drywall of the garage ceiling which couldn't be helping things! I've been meaning to fix them.....
I live in Milwaukee, WI and insulated my unheated attached garage several years ago. I was amazed at how much warmer it made the garage. I would guess that the garage is about 20 degrees warmer than it was before.
It seems to me that having a warmer unheated space beneath your bedroom can do nothing but help.
Call your HVAC contractor back, or call a second one in for another opinion. Because they used flex duct does not mean that dampers could not have been installed. That is BS period. If the new heat pump was sized correctly and the air handling unit is also properly sized, you should have adequate air flow and supply to every room on the system. There is a lot more to system design than squre footage and unit sizing.
We have a guy here that does just such design work for a living. Hope Tim pops in here to give you some advice.
heat rises. need i say more..
they shouldnt be there for health and enviromental reasons but if you got them treat them as living rooms and vent them after each car leaves and heat them up again
Ha! As if a car has ever actually been in my garage........