Non A C locations

[Anonymous]

Jet rock, You could use an R-19 which comes in two widths for 16" on center and 24" on center and is designed for 2x6 walls or ceilings. I would however use the ridged styrofoam baffle I mentioned in an earlier post.

[Anonymous]

Not sure where you're located but you can achieve an R value of around 20 by using 2 layers of 2" foam in your existing roof framing. Up in the north, we design for a minimum of R30 in the roof of a house, but for the conditions you describe R20 might be adequate. We can get it in 2'x8' sizes which makes it handy for putting between rafters.

The depth of the airspace isn't critical and more isn't necessarily better. With a standard 2x6 rafter, you should have 1 1/2" left after installing 4" foam which is more than enough. A 1 inch space is plenty.

Make sure you get the right foam, though. The pink or blue foam is for insulation, has a higher R value and has fire-resistant properties. The white foam, or beadboard foam, is what they make coffee cups out of, has a much lower insulating value & is much more dangerous in a fire.

Wayne

[nfmisso]

Another option is to put an external roof on top of what is there, use 2x4 on edge aligned with the existing 2 x 6 rafters, then metal or plastic roofing. If you do that, then you can eliminate the air gap on the inside, and just use fiberglass between the 2x6.

[Jetrock]

The only problem with increasing depth is that the ceiling is less than 7 feet high as it is--by adding depth to the rafters I'd be shrinking the garage! Admittedly, I'm only 5'9" so it's not like I'd be bumping my head, but since the garage is also my storage area I'd lose space to put things with every inch--heck, bringing it down to the current bottoms of the rafters would cost me storage space, as my drums are currently stored on a 6' high shelf above the layout and, since they are 15" floor toms, they poke up in between the rafters.

I suppose I could find another home for them...but the point is that I don't want to lose vertical space. 2" of Styrofoam and 4" of air space is about the best I think I can do...

[Anonymous]

Jetrocjk, you could as we in my field sat fir down meaning add 2x rips to the bottom of the raftersto increse the depth. Basically changing a 2x6 to a 2x10 or 12 then you could use an R-30 insulation(ceiling) R-13 to R-19 (walls). If your worried about keeping the air gap, they sell a inexpensive styrofoam baffle found at home depot or Lowes that can be stapled to the sheeting that will maintain this very important air gap.

[Jetrock]

QUOTE: Originally posted by carpenter matt

Jetrock, What's the space between the rafters measure? What is the width of the rafter as if it were laying on a table and your measuring across the board?

24" from rafter to rafter. The width of the rafters: 8 feet, 2"x6" board. (not sure what you meant by width, so I include all three dimensions.)

Near as I can tell, I suppose I could put 2" Styrofoam between the ceiling and the lower end of the rafters, using some sort of spacers (made out of extra styrofoam?) to leave an air gap, while leaving a gap on either end of the Styrofoam to permit airflow. I could finish it by putting up sheetrock and leaving a vent hole (with some sort of louvered vent cover) in each bay--that would provide airflow.

Kind of like this (spiffy ASCII diagram):

__________________________________________________________
[] II air space II air space II []
[] ################################################# []
[]-|||||-----------------------------------------------------------------------------------------|||||-[]

________ = roof line
[] =wall of garage
II =spacer (to provide air gap)
######## =Styrofoam sheet
-------------- = sheetrock
||||| = louvered vent

Thanks for the feedback...

[cwclark]

I converted a detatched workshop into a train room...I had to remove a garage door and build a wall and put in plenty of insulation.... I did however put in a 110 A/C window unit...It gets real hot here in Texas in the summer time and since nickel silver rail is vulnerable to expansion and contraction during the seasons I thought it best to put in the A/C ..I cut a hole in the wall and mounted the unit in the hole..I was lucky too...The BTU rating for the unit was only 30 cu. ft. over the size of the room...it's comfortable in the room and i keep it as close to 73 degrees as I can....this winter I think i'm going to go with electric heat but we only have about 3 weeks of cold weather here so I'm not to concerned about heating the room for long periods of time...Chuck

[Anonymous]

QUOTE: Originally posted by Jetrock
[The only thing I can think to do to insulate is to stick sheets of Styrofoam (you know, that stuff we build model railroad scenery out of apparently has other uses!) to the ceiling and maybe sheetrock over it. Would this help or will the lack of airspace/clearance do more harm than good?

The importance of airflow above the insulation & below the roof decking is to allow trapped air to escape without its moisture condensing on insulation and the wood, causing rot. You can accompli***his with even with your flat roof by leaving an airspace of 1" or more above the insulation and installing vents in the fascia boards that close off each bay of the roof. The easiest way may be to install a continuous louvered soffit vent in the fascia boards. There are small round vents that you can install by using a circle cutter to cut through the fascia. Remember to install the vents at each end of each bay, make sure the louvers point down and that there is nothing obstructing the flow of air within the bay, like bridging or heaped insulation or cats.

Wayne

[Anonymous]

Jetrock, What's the space between the rafters measure? What is the width of the rafter as if it were laying on a table and your measuring across the board?

[Jetrock]

I keep my layout in a non-air-conditioned (or heated) detatched garage. It doesn't get very cold here (three or four days a year it drops below freezing) but it sometimes hits 110 degrees in summer, and the garage is typically at least a few degrees warmer than the outside air. I have a big fan for when I'm inside but it doesn't run when I'm not there.

I would like to insulate my garage, but it's kind of a cramped space--it is a detatched garage, about 8 feet wide by 18 feet deep, and the roof is about 7'5" high (inside clearance under rafters is about 7'.)The roof isn't quite flat, it is canted towards the back so rain runs off (it doesn't snow here) and humidity isn't a problem in summer (it normally doesn't rain between May and October.)

I don't keep the car in the garage. It doesn't fit, anyhow, and only barely fit when the garage was empty.

The problem is that because of the flat roof there is no "attic" and therefore no roof vents and of course no airspace between the insulation and the roof. The only thing I can think to do to insulate is to stick sheets of Styrofoam (you know, that stuff we build model railroad scenery out of apparently has other uses!) to the ceiling and maybe sheetrock over it. Would this help or will the lack of airspace/clearance do more harm than good?

[Anonymous]

QUOTE: Originally posted by nfmisso

I second the insulation suggestion, and make sure that you do it properly.

There should be a relatively unrestricted air path from the soffet vents to the ridge vents all over. This keeps the bottom side of the roof at the ambient air temperature, and will greatly reduce the heat build up due to radiant heating from the sun.

To accompli***his, you may have to box in the rafters, then insulate, then another wall/ceiling.

While you are at it, sheet rock the garage area where the cars go, cars have been known to catch on fire, and the sheet rock will provide precious minutes of protection for your trains.

Good point on the air gap between insulation and roof sheeting, it will also promote shingle life.

Here in Ohio 5/8 inch drywall is required by building codes between any living space and garage. Some commercial building projects i have worked on actually do two layers of 5/8 drywall, for instance between two buisnesses in a strip mall if there is no masonry
wall seperating them.

[nfmisso]

I second the insulation suggestion, and make sure that you do it properly.

There should be a relatively unrestricted air path from the soffet vents to the ridge vents all over. This keeps the bottom side of the roof at the ambient air temperature, and will greatly reduce the heat build up due to radiant heating from the sun.

To accompli***his, you may have to box in the rafters, then insulate, then another wall/ceiling.

While you are at it, sheet rock the garage area where the cars go, cars have been known to catch on fire, and the sheet rock will provide precious minutes of protection for your trains.

[Anonymous]

rt2907, I would recommend insulating the walls floor and ceiling first. Then drywall. You might want to see if your able to tap into existing Heat/AC runs as well as cold air returns. Keeping the area well climatized will help. If you can't attach to heat/AC at least insulate it will make a difference in the summer keeping roof heat(sun hitting shingles) to a minimum. In the winter it will make make it more bearable by keeping the cold out. I would recommend a dehumidipher being ran in the summer. It would take the humidity out much like an AC system (making it feel cooler) and keep benchwork from warping and the possibility of items from rusting.

If I left any holes in my explanation or something seems confusing I will check back.

[Anonymous]

I am planning a layout over an unheated and un air-conditioned garage. Does anyone have any tips or experience doing this? I will have an attic fan controlled by a thermostat and I am in Kentucky so it doesn't get too cold usually. Thanks Bob T