Compression test on UFFI Foam Insulation © Daniel FriedmanHow to Identify UFFI in BUILDINGS
Simple crush test + signs of indoor or outdoor insulation retrofit

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UFFI recognition & identification in buildings:

This article illustrates some simple ways to distinguish UFFI from other types of foam insulation found in buildings. We also describe visual clues that indicate that an insulation retrofit job has been done at a building from outside or inside.

This article series on UFFI insulation illustrates and describes UFFI - urea formaldehyde foam building insulation and describes where it is found, when it was used in buildings, how to look for it, how to distinguish this from other building foam insulation products, and its health effects. We include identification photographs and a description of a very simple field test that can immediately distinguish between 1970's vintage sprayed or pumped UFFI insulation and more contemporary icynene or polyurethane spray foam insulation jobs.

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How to Identify UFFI or Urea Formaldehyde Foam Insulation in buildings

Our photo (below) shows the dark dusty skin on UFFI insulation where it oozed from a wall cavity opening into a crawl space in the attic over a building garage.

UFFI Insulation in a building attic © Daniel Friedman

If you are having trouble determining what type of foam insulation product has been installed in a building,
see FOAM SPRAY INSULATION TYPES for more detail on the identification of these products in the field. There you will see more examples of the foam insulation press and crush test that our photos illustrate just below.

Squash test on UFFI Foam Insulation © Daniel Friedman

If the insulation is UFFI, it easily crushes to a fine powder - (below).

Compression test on UFFI Foam Insulation © Daniel Friedman

How to Find & Identify UFFI Insulation in an Older Home by Visual Indoor Inspections: Insulation Retrofit Projects

Below we give specific inspection methods useful in building interiors and exteriors that will help spot the types of insulation that may have been added to a building over its life.

Drill marks where UFFI was pumped into building walls © Daniel Friedman

Look at interior or exterior building walls for evidence of openings that were cut or drilled to blow-in building insulation.

Since the same type of round openings are used for blowing in cellulose or at least two different types of foam building insulation, if you see these marks or round hole cuts you will need to investigate further to identify the specific type of insulation that was installed.

Our photo (left) shows interior drill holes in an attic stairwell where insulation was pumped into the building wall cavities. Why so many holes? The first cuts probably hit wood framing.

Photos of typical holes found in a building exterior where insulation was blown or pumped into the wall cavities are provided in detail below
at How to Spot UFFI Building Insulation in an Older Home by Visual Outdoor Inspections.

Look in basements and crawl spaces for evidence of UFFI (crumbly) foam exuding out into the basement or crawl space at the bottom of wall cavities. Often there were gaps that permitted this foam escape - usually it was just left in place. Where balloon framing techniques were used, depending on the adequacy of fire blocking in wall cavities, foam injected into the walls may have passed between floor levels and easily into an attic (as shown in our photo above) or into the basement or crawl space as shown below in the left hand photo.

UFFI insulation oozing out in a  basement © Daniel Friedman

Look in un-finished areas such as attics and closets where plaster and lath are left incomplete or where drywall has been omitted during a building retrofit. Our photos below show UFFI insulation pushing on a poly plastic vapor barrier. Someone has cut the poly in the left photo, perhaps to sample the material - a step that was unnecessary if the inspector simply looked down at his or her feet (photo below-right).

UFFI insulation behind plaster lath © Daniel Friedman

You may also be able to see UFFI or other types of foam insulation oozing out from large openings at the sill plate between floors (photo below-left) or UFFI foam may have oozed out of even small wall openings as we show in the right hand photo of an un-finished plaster lath wall (below right).

UFFI insulation behind plaster lath © Daniel Friedman

Look for small amounts of soft crumbly foam insulation at tiny openings in wall cavities such as at knot-holes or gaps between siding boards, as we show on our photo (left).

UFFI foam insulation visible in a gap between building sheathing boards © Daniel Friedman

You may need to probe this material to evaluate its density and fragility. If the material easily crumbles to a powder, it is probably Urea Formaldehyde Foam Insulation or UFFI Foam.

Look for scalloped drywall on the inside surface of building exterior walls: often the UFFI foam insulation was sprayed with more water content than specified; because the insulating material could be quite wet when first installed, we found that in some old homes which had been renovated by replacing original plaster with drywall, the drywall became wet, bonded to the UFFI, and then actually became sunken or concave along the building exterior walls as the UFFI insulation cured.

We pose that the drywall had become soft while wet, that it bonded to the UFFI in the wall cavity, and that as the UFFI insulation dried and cured it also shrank, pulling the damp drywall sections inwards.

We first spotted this phenomenon in an 1890 home in Wappingers Falls, NY when the home was insulated with UFFI spray in the 1970's.

Looking along the top edge of the baseboard trim at the bottom of the wall we saw that the drywall was in contact with the trim only at the location of the wall studs, and that between each pair of studs the drywall was concave.

How to Spot UFFI Building Insulation in an Older Home by Visual Outdoor Inspections: Insulation Retrofit Through Siding

UFFI blow in plugs © Daniel Friedman

As our pumped-in UFFI insulation retrofit job photos show, plugs may be visible in siding boards, but we warn that they also may have been covered by replacement boards or by a new layer of exterior siding. Also this plug and pump method for blowing insulation into building walls was used for more types of insulation than just UFFI.

UFFI insulation plug © Daniel Friedman

Article Series Contents:


Continue reading at UFFI SHRINKAGE, THERMAL BYPASS LEAKS or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.


Or see URETHANE FOAM Deterioration, Outgassing

Or see FORMALDEHYDE GAS HAZARD REDUCTION for other measures to reduce indoor formaldehyde levels



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UFFI, HOW TO IDENTIFY in BUILDINGS at - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.


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