Adding a 1″ gap behind the XPS creates a dead air space that adds to the R value of the overall insulation. This is a standard recommendation with sheet foam insulation. It does assume that you have a good seal at all joints. If you have a moisture seepage problem, this doesn’t add to it.
Do you need a vapor barrier with XPS?
However, XPS is considered a vapor retarder, not a vapor barrier. Although higher densities of EPS have a greater compressive strength than lower densities, EPS is never as strong as XPS and is more susceptible to crumbling at the edges and to other jobsite damage, which is why EPS is rarely used for wall sheathing.
Can rigid foam get wet?
Foam board insulation products are generally considered water and mold resistant but expanded polystyrene foam boards (EPS) have air bubbles that can collect moisture and become wet. Moisture makes it hard to prevent mold from growing, making the foam board also prone to mildew growth.
How do you install rigid foam in a basement?
Use a wooden board (or similar) to hold the rigid foam insulation up tightly to the foundation wall while the adhesive sets up. Be sure to apply rigid foam boards to foundation walls within 15 minutes after the adhesive is applied.
How do you install foam board insulation on concrete?
Quote from the video:
Quote from Youtube video: It into the position you want pull it away for about thirty seconds it lets the the glue itself kind of start to react and then press it back on and chances are it'll stay there all on its own.
Does XPS melt?
XPS is a thermoplastic material which softens at 165°F and melts in the 200°F to 210°F range.
How thick should foam insulation be in a basement?
The thickness of foam insulation in basement walls will range between two to seven inches, depending on where you live and whether you use open or closed-cell spray foam insulation.
Does XPS foam absorb water?
FOAMULAR® XPS products have an R-value of 5 per inch of thickness, and due to their closed cell structure they resist water absorption, maintaining a high R-value for reliable long term service.
Is XPS foam waterproof?
Technically, EPS and XPS rigid foam board insulation are considered to be water-resistant. A product branded as waterproof means that it offers complete impermeability, even if permanently immersed in water.
Does rigid foam insulation need to be covered?
Tests have shown that these laminated boards can withstand UV ray damage for a reasonably long time. That said, it’s still advisable to cover any foam board insulation exposed to the Sun within 30-60 days at the most. On most projects, that’s more than enough time to finish the exterior walls.
Does rigid foam insulation need vapor barrier?
Foam insulation usually does not require a vapor barrier. For some foam insulation types, such as closed-cell spray foam and foam board insulation, the insulation itself stops the movement of most water vapor.
How do you cover rigid insulation on a foundation wall?
The most common approach is to apply a stucco-like “parged” finish with a surface-bonding cement. These finishes range from a thin paint-on coating to a thick acrylic-modified mortar applied over hardware cloth or metal or fiberglass lath. The thin paint-on coatings are easily chipped and prone to peeling.
How do you insulate concrete basement walls?
Quote from the video:
Quote from Youtube video: So you don't need a lot of insulation on basement walls in fact. You can do the job well with just a two inch layer of polystyrene stuck right to the surface of the concrete.
Do you need a vapor barrier on basement concrete wall?
Building codes usually require a vapor barrier (4 mil plastic sheeting) on exterior basement walls if the framing is attached to masonry or concrete surfaces, or if the wood framing butts up against the outer basement walls.
Do I need to insulate below grade basement walls?
Your best bang for the dollar in this instance is to insulate the coldest part of the wall, again typically to 2-feet below grade. However, there are many instances where insulating the full wall is the best option, such as if your walls are stone, or the floor is earth or crushed stone with no vapor barrier.
Should you insulate concrete basement walls?
Walls. Basement walls should be insulated with non-water sensitive insulation that prevents interior air from contacting cold basement surfaces—the concrete structural elements and the rim joist framing.
Do basement walls need to breathe?
Nowadays, houses are sealed up tight as a drum. It’s great for energy efficiency and your heating bill. But it’s bad for any moisture hiding in your home that can’t find its way out. That is why your walls need to breathe.
Is it worth insulating basement walls?
Basement Insulation. A properly insulated basement can save you money on heating and provide a dry, comfortable living space. In most cases, a basement with insulation installed on its exterior walls should be considered a conditioned space.
Will insulating basement make house warmer?
Yes—in most cases insulating your basement is a good idea because it will pay dividends down the road. Not only does wall insulation help keep your home warmer but it may also help soundproof the space.
Which way should insulation face in basement?
Whether it’s in a basement, a crawl space, or an attic, the insulation should face the unconditioned side of the house, while the paper faces the conditioned side. Insulation gets installed in this manner to prevent moisture and water damage from occurring.
Should you insulate between basement and first floor?
Yes. Faced insulation is actually recommended on basement ceilings and ceilings in general. The covering or “face” of the insulation prevents it from falling out and trickling down into the basement air.
