basement insulation panels that DO NOT need to be covered with dry wall
My buddy is getting ready to build a new house in Michigan and has to have the basement walls insulated to R10. He doesnt want to insulate the outside due to having to cover the insulation at grade and with his walk out etc it might not work out the way he wants. He also doesnt want to insulate the inside with sheet as he does not want to finish the basement at time of construction so he does not get with the additional taxable sg/ft snd he is not too keen on the wall “blanket” type insulation either..
He was talking to the local inspector who told him about a newer product that is a sheet but does NOT have to be drywalled over for fire protection. The inspector couldnt remember the name of it and we are coming up blank on Google etc searchs.
Does this sound familar to anyone out there? Any info/experience with it? Good/Bad/Indifferent??
Thanks guys
J-
Replies
Interior Basement Insulation Options
Blue Dow STYROFOAM can be left exposed up to 3" in thickness (R15) in basements, crawl spaces and attics per the attached ICC-ES Code Report ESR-2142. Section 4.2.1 and Table 1 in the code report provide the details for the exposed use in basements, crawspaces and attics. You can achieve the requested R10 with 2" of STYROFOAM.
Dow THERMAX foil faced polyisocyanurate insulation can be left exposed up to 4-1/4" thick.
I'd get an interpretation first...
Section 4.2.1 is for "Use Group U" structures. A residential house and its basement do not fall into that classification.
I think of "U" as being "U"tility or accessory structures; barns, sheds, greenhouses, etc.
Sounds like your buddy is being careful to imitate decades of failed basement construction practice. Do him a favor, and hear me out ...
You do NOT want to make your basement walls the 'same way' you make the house walls. Basements are/ will be wet. It's a simple fact. NOW is the time to plan, so as to reduce moisture issues.
#1: Have a good, flat floor. The usual basement floor is not nearly as flat as the driveway - and invariable puts the sump pump at the highest point. He'll need gypcrete, or some other specialty topping, to level out all those water-pooling low spots. Make sure water can drain!
#2: Leave a space between the basement walls and the new walls. Drywall suppliers can provide "hat channel," which will hold the framing 3/4" off the wall. It's OK to run your wiring in this gap.
#3: Provide some means for moisture to drain under - and not be trapped by - the bottom plates of walls. If you use metal track, put a weep hole in every stud bay (on the room side).
#4: Nothing within the bottom 6" of the walls should be able to absorb, or be damaged by, water- period. That means NO wood, NO fiberglass, NO drywall.
#5: Basements have their own "climate." They deserve separate heating, cooling, and plenty of direct intake of fresh air - to remove any moisture.
R-10? That breaks down to about 2-1/2" of foam board. You can readily get metal framing sized to approximate 2x3" lumber, so the panels will be held snugly. leave about an inch of clearance at the floor, to prevent wicking or pooling of water.
For fire resistance, there's simply no substitute for gypsum board. Yet, gypsum will degrade over time in a moist area, and the facing paper will grow mold. Ugh! About the best you can do make your lowest 6" or so from DuRock; Densshield or "extended exposure" fiberglass faced drywall for the balance. Maintain at least an inch of clearance between the bottom of the boards and the floor itself; this is to prevent wicking.
In a like manner, I suggest a similar approach to the floor, raising the finished floor above the concrete.
He doesn't want to "finish" the basement? Why do folks work so hard to lie? When did lying become a virtue?
Sounds like your buddy is being careful to imitate decades of failed basement construction practice. Do him a favor, and hear me out ...
You do NOT want to make your basement walls the 'same way' you make the house walls. Basements are/ will be wet. It's a simple fact. NOW is the time to plan, so as to reduce moisture issues.
#1: Have a good, flat floor. The usual basement floor is not nearly as flat as the driveway - and invariable puts the sump pump at the highest point. He'll need gypcrete, or some other specialty topping, to level out all those water-pooling low spots. Make sure water can drain!
#2: Leave a space between the basement walls and the new walls. Drywall suppliers can provide "hat channel," which will hold the framing 3/4" off the wall. It's OK to run your wiring in this gap.
#3: Provide some means for moisture to drain under - and not be trapped by - the bottom plates of walls. If you use metal track, put a weep hole in every stud bay (on the room side).
#4: Nothing within the bottom 6" of the walls should be able to absorb, or be damaged by, water- period. That means NO wood, NO fiberglass, NO drywall.
#5: Basements have their own "climate." They deserve separate heating, cooling, and plenty of direct intake of fresh air - to remove any moisture.
R-10? That breaks down to about 2-1/2" of foam board. You can readily get metal framing sized to approximate 2x3" lumber, so the panels will be held snugly. leave about an inch of clearance at the floor, to prevent wicking or pooling of water.
For fire resistance, there's simply no substitute for gypsum board. Yet, gypsum will degrade over time in a moist area, and the facing paper will grow mold. Ugh! About the best you can do make your lowest 6" or so from DuRock; Densshield or "extended exposure" fiberglass faced drywall for the balance. Maintain at least an inch of clearance between the bottom of the boards and the floor itself; this is to prevent wicking.
In a like manner, I suggest a similar approach to the floor, raising the finished floor above the concrete.
He doesn't want to "finish" the basement? Why do folks work so hard to lie? When did lying become a virtue?