What kind of insulation to use for my basement?

mystikyJune 25, 2013

Our newly rebuilt basement is taking shape and soon we will start closing it with sheetrock, meaning that we have to decide on insulation.

The house is all-brick from 1930's here in Brooklyn, NY. It has all new sewers and I have never seen any water in the basement during the few years we have owned the house. The basement goes about 5 feet underground (measured from the inside) The only heating / air conditioning in the basement will be provided by a 9,000 BTU LG HVAC system airhead. I plan to install a portable humidifier that will be periodically on. Summers here are very humid and winters are dry.

A few suggestions were made to me about which type of insulation to use, so I would like to hear some feedback on each method:

1) Using the spray-on foam. But which one? I hear that if it's not done properly, it could create a bad moisture situation
2) Using the standard R-11 that is sold in Home Depot / Lowes
3) Using Roxul's product Comfortbatt (R15/16 or R23):

Also: Will I need a vapor barrier in general?

Any and all opinions are much appreciated!

Thank you for reporting this comment. Undo

Your choice of insulation is a matter of building science, not opinion. See link.

Your choices are still wide however.

But, first, no fibrous insulation against the exterior wall unless it's on top of foam. You can use closed cell spray foam (ccspf) extruded (XPS) or expanded (EPS) polystyrene foam boards or polyisocyanurate foam boards, either by themselves or in conjunction with fibrous insulation. Open cell spray foam (OCSPF) can also be used but with precautions, as it is vapour permeable.

Extruded polystyrene foam board on basement wall.

I've often used the lightweight steel framing you have. A lot easier and cleaner to install than wood and no screw pops later on. The only flaw is that there should have been at least a layer of 6 mil poly under the baseplates to keep rising moisture away from the galvanized. (I actually put strips of 1" XPS under the baseplate.)

The biggest drawback to professionally applied SPF is cost followed by the risk that an untrained applicator mixes an inferior product and/or does not apply it properly.

If this is a diy job, applying XPS boards would be my first choice. But that would have been more easily done before the framing was installed. You now have to slip it in behind a finished wall. Then follow it up with high density fiberglass batts or Roxul rockwool. Also, piece in in XPS boards at the rim joist, caulking and foaming them tight.

Here is a link that might be useful: Building Science Corp.: Basement Insulation

This post was edited by worthy on Tue, Jun 25, 13 at 19:48

    Bookmark   June 25, 2013 at 7:30PM
Thank you for reporting this comment. Undo
Windows on Washington Ltd


Get over to Building Science.com.

Easiest Homeowner (also more cost effective) will be to go with rigid foam and batt insulation.

Depending on climate location, no vapor control beyond the primed and painted drywall should be required.

    Bookmark   June 29, 2013 at 8:17AM
Sign Up to comment
More Discussions
Ceiling insulation in basement
We are finishing our basement and I am getting to the...
basement flooring - tile or finished concrete
we're planning a reno that will include expanding and...
Mysterious Concrete Box in Basement
I am considering placing an offer on a house (built...
Adding toilet to basement
We are adding a half bath to our basement when we start...
Str'l Wood Floor + CrwlSpace vs Concrete Slab
Hello, We were discussing our plans with a builder...
Sponsored Products
Westek Under Cabinet Lighting LED Slimline White Puck (3-Pack) LED32HBCC
$40.88 | Home Depot
Globe Electric Recessed Lighting 5 in. Recessed Dark Bronze Sleek Directional
$39.00 | Home Depot
Lithonia Lighting 40-Watt Gray LED Cable-Mount Shoplight 1292L
$99.97 | Home Depot
Odyssey Counter Height Pub Table Multicolor - ODYP3838
Shanghai Oval Pendant by Trend Lighting
$500.00 | Lumens
K&H Manufacturing Lectro-Soft Outdoor Heated Bed Multicolor - KH1070
$57.99 | Hayneedle
Gym Flooring: Groovy Mats Flooring Green 24 in. x 24 in. Comfortable Mat (100
$1.99 | Home Depot
Napoleon 40 in. Built-in Electric Firebox Insert - BEF40H
People viewed this after searching for:
© 2015 Houzz Inc. Houzz® The new way to design your home™