Is PU foam insulation good?

Polyurethane foam insulation is a modern and highly effective method of the thermal insulation of buildings. When applied by spraying, it reaches even the smallest of gaps. It provides the permanent and damage-resistant insulation of a house, improving living comfort, and reducing heating bills.

What is PU expanding foam?

What are the Types? Polyurethane foam is one component, curing with moisture in air, expanding while curing, semi-rigid in aerosol form for installation, grouting and insulation material.

What are the 2 main types of polyurethane foam?

Polyurethane foam is divided into two basic types — open-cell and closed-cell. The former is intended for indoor use, particularly for insulating walls and roofs as well as increasing acoustic comfort of a room, as polyurethane foam — besides thermal insulation properties — has a very high noise reduction coefficient.

How long does PU foam last?

The lifespan of polyurethane will depend on the application and the type of use. Under normal use and regular wear and tear, we can expect a lifespan of: 50+ years for building insulation. 25+ years for refrigerators.

What are the disadvantages of polyurethane insulation?


  • Poor thermal capability.
  • Poor weatherability.
  • Attacked by most solvents.
  • Utilize toxic isocyanates.
  • Flammable.

What are the disadvantages of foam insulation?

Below we are going to list the most common problems with using spray foam insulation in your home’s attic or in any area inside of your home.

  • Placement Errors During Installation.
  • Potentially Attracts Water Damage.
  • The Material May Shrink Overtime.
  • Long Dry and Cure Time.

Is PU foam waterproof?

The short answer is yes, to a certain degree. There are several factors that make some polyurethanes more absorbent than others. Depending on the physical properties and material, thermoset polyurethanes can practically have zero water absorption compared to other known materials.

Is expanding foam same as PU foam?

What is expanding PU foam? Expanding foam, or PU foam, is ideal for patching up cracks, and filling in cavities, gaps and other empty spaces that can affect insulation around the home.

What are the disadvantages of polyurethane?

Polyurethanes do not survive well in direct sunlight or in contact with most organic solvents.


  • Poor thermal capability.
  • Poor weatherability.
  • Attacked by most solvents.
  • Utilize toxic isocyanates.
  • Flammable.

What is PU foam used for?

Polyurethane, mostly in the form of flexible foam, is one of the most popular materials used in home furnishings such as furniture, bedding and carpet underlay. As a cushioning material for upholstered furniture, flexible polyurethane foam works to make furniture more durable, comfortable and supportive.

What are 2 benefits of using polyurethane?


  • High abrasion resistance.
  • Good low temperature capability.
  • Wide molecular structural variability.
  • Ambient curing possible.
  • Comparatively low cost.

Is polyurethane foam toxic?

Polyurethane foam itself is not toxic, but is it dangerous for any other reason? Answer: Yes. The main danger of polyurethane foam at the manufacturing stage is actually flammability. Low-density foam has a high surface-to-volume ratio and also high air permeability, making it very susceptible to catching fire.

Where should you not use expanding foam?

When NOT to Use Spray Foam Insulation

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

Why do lenders not like spray foam insulation?

Because getting rid of SPF once it’s in place can be exceedingly difficult, often causing even more damage. The main reason that mortgage lenders may initially decline you is because the roof space has been sealed with SPF, which restricts air circulation, leading to condensation and wood rot, as mentioned above.

Is polyurethane a waterproof?

This finish protects your floors, but polyurethane is not waterproof. It will make your floors water-resistant, though — the coating repels water and helps prevent water absorption.

Is polyurethane foam strong?

Just How Strong is Polyurethane Lifting Foam? Polyurethane lifting foams create an abundant amount of lifting power to raise settled concrete. They provide enough strength to support a slab enduring just about any load.

What are the disadvantages of PU?

Is PU foam carcinogenic?

Once the chemical reaction of its components has taken place, the result is a polyurethane foam that is completely inert and harmless to humans. Contrary to what some people claim, various studies certify that polyurethane does not pose a risk to the health of users.

Does polyurethane foam smell?

Memory foam is manufactured using polyurethane and several other chemicals, so it isn’t surprising that it emits a chemical odor. This “off gassing” of volatile organic compounds is a common and well-documented property of memory foam pillows and mattresses.

What happens if spray foam gets wet?

Wet Spray Foam Insulation

Though spray foam doubles as a moisture barrier and creates an air-tight seal, the leak is still problematic because water can damage the wood surrounding the insulation. Find the hole and seal it to protect your home’s porous structures from moisture damage.

Does spray foam devalue your house?

In fact, according to Heritage House, they have seen entire roofs rotted and unrecoverable after SPF has been used. They state that by using SPF in your roof, ‘…you will devalue your home by the amount that a new roof will cost, and more. ‘ And we agree.

Can mold grow behind spray foam insulation?

Yes, because spray foam creates an air seal and will starve that mold of its food source — moisture and oxygen — and will inhibit any future growth, it will also cause the mold to become dormant. There is the bigger question though of why does that mold grow in attics?

How many coats of polyurethane are waterproof?

About three layers of polyurethane are usually recommended for the best protection. The product doesn’t penetrate the wood like stain and other wood finishes. Instead, it forms a transparent coat on the wood surface. The more layers you apply, the thicker the coat and the better the protection.

What is the main disadvantage of using water-based polyurethane?

Cons of Water-Based Polyurethane
Expensive cost. Requires more coats. Scratches easier due to it hardness.

Is Pu harmful?

This leads to a frequently asked question; do polyurethane products that come into contact with humans present any kind of health risk? The short answer is that no, polyurethane is not toxic. It is actually a safe and sustainable option when compared to many alternative materials.