Should you put a vapor barrier on basement walls?

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.

What are the pros and cons of spray foam insulation?





A Breakdown Of The Pros & Cons Of Spray Foam Insulation

Pros and Cons of Spray Foam Insulation
Advantages Disadvantages
Creates a highly energy efficient thermal envelope Upfront costs are high and installation is expensive
Extraordinary thermal qualities Payback takes 2-4 years
Lower ongoing energy costs Not a DIY product

Where should you not use spray foam insulation?

When NOT to Use Spray Foam Insulation

  1. For areas that are too close to electrical boxes:
  2. For areas too close to ceiling light boxes:
  3. Open-cell spray foam on your roof:
  4. For closed-cavity spaces:
  5. If you have a history of skin, respiratory, or asthma problems:

Should you spray foam basement walls?

The best way to insulate the interior side of a basement wall is with foam insulation that is adhered to or sprayed directly on the concrete. Any of the following insulation materials are acceptable for this purpose: closed-cell spray polyurethane foam or either XPS, EPS, or polyisocyanurate rigid foam.

Does rigid foam insulation need a 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.

Does spray foam insulation deteriorate?

Spray foam insulation deteriorates IF it is not well installed. However, high-quality, well-balanced spray foam insulation can last for as long as the house stands. These factors can speed up your spray foam insulation’s deterioration.

Why do lenders not like spray foam insulation?

So why is it a problem for mortgage lenders? By sealing the roof space with this material, air circulation can be restricted to the roof and timbers. This can lead to condensation, which in turn can eventually lead to the rotting of the wooden roof supports.

How long does spray foam insulation last?

Typical Insulation Lifespan



The International Association of Certified Home Inspectors states that spray foam insulation, wrap tape and housewrap insulation can last for more than 80 years. At the same time, cellulose, loose-fill, foamboard, loose fill and rock wool insulation can last up to 100 years.

What is the R-value of closed cell spray foam?

R-6.5-7 per inch

The R-value of closed-cell foam is R-6.5-7 per inch. Contractors often use it to insulate under slabs, ceilings, walls, and roofs. It performs better than other insulation types. It provides an excellent air barrier, resists moisture, and retards vapor.

Do you need vapor barrier with closed cell spray foam insulation?



In houses with spray foam insulation, however, vapor barriers are not necessary. Quality closed cell foam insulation acts as a vapor barrier and does not absorb moisture; at the same time, the insulation prevents leakage by closing air gaps.

What is the cheapest way to insulate basement walls?

The smart and inexpensive way to insulate joist bays is to use extruded polystyrene (XPS) foam insulation panels cut to size to fit inside the bay and “glued” in with expanding foam. When the expanding foam hardens, trim away the excess and cover the foam with a piece 1/2″ thick drywall to meet fire code.

Do i need foam board in basement?

If you are planning to finish the basement space, you should also consider adding a layer of foam insulation below the slab. The insulation may not save much money in energy bills due to moderate earth temperatures at that depth, but it will warm the floor surface enough to reduce condensation.

How thick should foam insulation be in a basement?

Boards come of varying thickness up to 2in. You get a thermal capability of R5 per inch of thickness. I recommend going with the 2in thick for an R10 rating. The board is more expensive than blanket insulation.

Is insulating basement walls worth it?



Insulating your basement may seem like a project best suited for another day, but truthfully, insulating your basement walls can help improve comfort and reduce energy and maintenance costs to HVAC systems. It also allows for extra living space within a home, which can be invaluable.

How do you cover rigid foam insulation?

If the rigid foam board is not too thick, drill a hole through the rigid foam board up to at least half an inch on the foundation wall. If the rigid foam board is too thick to have a screw penetrate its thickness with at least half an inch more to penetrate the wall, then use foam board adhesive instead.

Do unfinished basement walls need insulation?

There should be no need to provide heat to your unfinished basement. Performing air sealing work and insulation improvements will make the space more comfortable. Rigid EPS or polyiso are greener and cheaper than closed cell polyurethane if the brick & CMU wall is flat enough.

Should unfinished basement ceiling be insulated?

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. This is especially advantageous if the insulation is made of fiberglass, which can harmful if it’s ingested.

Should I spray foam my basement ceiling?



Best Insulation for a Basement Ceiling: Closed-Cell Spray Foam. The best tip to keep in mind when it comes to basement insulation is moisture control. To this end, a material such as closed-cell spray foam, which helps provide a water vapor barrier.

How do you insulate an unfinished basement ceiling?

Your best option is insulating your exposed foundation walls. Start with getting any moisture issues under control, then use water-resistant insulation like closed-cell spray foam or XPS foam board. Most homeowners opt for fiberglass, but fiberglass has the chance of trapping moisture.