Questions & answers about UFFI hazards, identification in buildings & Hazards.

This article series 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.

The insulation photo at page top shows an insulation retrofit series of projects. In the center of the photo we see pink fiberglass insulating batts.

Below the fiberglass insulation we see blown-in loose-fill cellulose insulation. And in the foreground (and under our © notice) we see a crumbly, cracked slab of UFFI foam insulation as well.

UFFI Insulation FAQs

These questions & answers about UFFI insulation were posted originally

at UREA FORMALDEHYDE FOAM INSULATION, UFFI - home - be sure to review that article.

I want to remove UFFI from my home - what's the size of its dust particles?

I am looking to remove the UFFI from the cavity walls of my house. Does someone know the particle size of UFFI dust?

I plan to purchase a HEPA filtered vacuum to collect and bag the material. I have seen vacuums claiming to collect everything above 0.3 microns in size. Thanks. - On 2018-06-13 by Thomas A Salisbury

Reply by (mod) - Possible particle sizes & hazards when removing UFFI insulation

Thomas

Because UFFI is so fragile its particles can easily include down in the 1u range.

Why are you removing the insulation? It is not harmful in place. The central issues with an older home with UFFI insulation are

1. gaps may have formed at top and sides of insulation pumped into wall stud bays if the mix was improper and the insulation shrank, leading to points of heat loss.

2. consumer fear: a residual consumer fear of UFFI, though generally not justified, can impact property re-sale time or price.

1 u = 1 micron in my lingo. sorry for the confusion.

I'd handle the job as if it were asbestos - controlling dust, negative air, thorough cleanup, so as to avoid leaving irritating dust particles for Mrs. Wife.

See UFFI REMOVAL PARTICLE SIZE HAZARDS where we have moved this discussion and the rest of your UFFI removal photographs.

 

Should I wear a dust mask during building repairs where UFFI is installed? - and is UFFI hard on your lungs?

If you are changing a window and find ufi in the wall should you wear a mask and is it hard on your lungs - On 2017-08-06 by Alan Brick -

Reply by (mod)

Alan

In my OPINION, the risk from breathing UFFI dust during building renovations is similar to the risk of breathing any old house dust that contains fine particulates, and it would be smart to minimize that dust exposure.

That is, ultra-small particulates can be harmful. See

There is no special hazard associated with UFFI related to the much earlier worry of formaldehyde offgassing - a gas not a particle - as by now any older UFFI installation won't be offgassing measurable formaldehyde.

But in my experience old UFFI insulation is soft and quite friable, so it would be easy to produce dust when renovating or demolishing an older building.

Is it OK to disturb old UFFI insulation and is it better to add air seals and more blown-in ceiling insulation?

We recently purchased a house built in the 1970s. As part of a small remodeling/expansion project, the workers removed the plasterboard on one segment of exterior wall. I am pretty sure (from what I've read online since then) that the insulation was UFFI: rigid, blocks of white open cell foam, very friable (crushable) to a fine dust.

For us, the most troubling issue is that every stud space had an approximately 1 inch gap between the insulation block and the stud on each side. "Off the top of my head" that seems to represent at least a 12% loss of insulating capacity. That is consistent with our perception that the house seems colder than the value represented by the thermostat reading.

Is there a recommendation for a cost-effective way to add insulating properties to the exterior walls without removing the UFFI? - On 2016-11-03 by Jerry

If you come across UFFI in older homes, is it acceptable to disturb it to add better air sealing and blown in insulation in walls/ceilings? - On 2017-04-19 by Chris -

On 2017-04-19 by (mod) - Older UFFI would not be at all likely to continue to be a formaldehyde hazard

Jerry and Chris :

In my opinion certainly yes. Older UFFI would not be at all likely to continue to be a formaldehyde hazard, having offgassed long ago; it will likely have shrunk. I'd consider

- leaving it alone and living with the risk of air leaks and heat loss around the sides and top of UFFI blown into walls

Watch out: at UFFI SHRINKAGE, THERMAL BYPASS LEAKS we show significant shrinkage gaps and thus air leak points and un-wanted heat gain or loss points that occur in some UFFI-insulated buildings.

- experimenting with pushing foam into those openings - highly labor intensive as you'd have to find the right drill spots around every stud bay;

if I were doing this I'd experiment with a single stud bay cavity, pushing foam in along the studs and at the wall top, using a foam that expands with as little pressure as possible - overpumping will just squash the UFFI needlessly; then I'd open that bay to see what happened - to evaluate the procedure.

- during major renovation work, open the wall, see where there are shrinkage problems (varying by UFFI mix) and if there are gaps and air leaks I might insulate around and add a vapor barrier or I might remove and re-insulate.

Beware that old UFFI is often very fragile, soft, crumbly into dust so fooling with it can be messy.

Jerry's remarks below summarize very well my own opinion about the UFFI shrinkage problem, but omitting that the impact of UFFI insulation shrinkage gaps will probably vary significantly:

- Where there are UFFI gaps that combine with air leaks into and out of a wall or ceiling cavity the energy cost may be significant; air leakage losses may overwhelm simple wall R-value calculations.

See AIR & HEAT LEAK FIXES
and
See AIR LEAK DETECTION TOOLS

- Where there are gaps but no wall air leaks (e.g. where there are no interior wall penetrations for wiring, plumbing, etc) there is a loss of insulating value but probably less energy costs

Question: renovation & ideas about handling an older Canadian home insulated with UFFI

My parents own an old foursquare brick house near London, Ontario. In the 1970's, my parents, with my suggestion (I was in high school at the time and headed for engineering school) put in UFFI in not one but two houses. In one house, we ended up removing it ourselves (government subsidized adding it and removing it, which in hindsight is quite funny).

The other house is the one they are still in. My parents have been very happy - quieter, more energy efficient and my Dad got a substantial tax break.

I'm writing because my parents are now quite elderly and they may have to downsize. I'm thinking of making a deal if this happens to take over this house as an income property, so that they can have a cash stream now and later I can tap into the same cash stream. I now work doing safety and environmental inspections of commercial buildings and I've sampled for UFFI.

Based on what I see, I'm leaning toward treating UFFI a bit like asbestos - remove where renovations are done, but otherwise leave alone (BTW the place also has asbestos on the boiler and pipes, some flooring and possibly other areas such as plaster, and I would strip out the old boiler and piping).

I can IR scan for shrinkage and possibly try that top-up if no one has tried. BTW I can line up air sampling for tenant peace of mind but I'm 100% sure that the results are below the detectable limit. Tearing down the property or removing all the brick and re-doing both seem both too expensive and too extreme.

Would this approach make sense to you? - P.C. 12/1/2013

Reply: UFFI installed in the 70's will not produce detectable formaldehyde in buildings

UFFI installed in the 70's will not produce detectable formaldehyde in buildings - it outgassed long ago; we agree that the insulation is fragile - and crumbles if disturbed, and that shrinkage might be worth attending, though even that improvement is questionable; I'd very much like to see an IR scan of the building walls mapping the extent of shrinkage;

I'm pretty sure if you decide to try injecting foam to improve the home's energy costs it'll be to stop air leakage rather than simply improving wall R-value.

In sum there is certainly no reason to remove the UFFI, and there is no reason to treat it as hazmat.

However, if you have a tenant who is hyperallergic to formaldehyde, you might want to screen the building for that gas, particularly if someone has used particleboard or other newer building materials.

If you find measurable formaldehyde levels that observation will almost certainly be traced to other materials in the building, not to UFFI wall insulation blown in during the 1970's.

Question: what is the R-Value or insulating value of UFFI ?

(Nov 28, 2015) Faith said:
very interesting article, any idea of what sort of r value uffi foam in a 4 inch cavity would offer?

Is there an issue with dampness with these foams?
Thank you

Reply:

Faith,

For information about UFFI's R-value - roughly R5 per inch or about R20 for a 2x4 stud wall before accounting for air leaks (if present) due to shrinkage (if it occurred)

see INSULATION R-VALUES & PROPERTIES at inspectapedia.com/insulation/Insulation-Values-Table.php
and
see HEAT LOSS R U & K VALUE CALCULATION - at inspectapedia.com/insulation/Heat_Loss_Calculation.php

...

Continue reading at UFFI, HOW TO IDENTIFY in BUILDINGS or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see these

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  • UFFI, HOW TO IDENTIFY in BUILDINGS
  • UFFI, HOW TO SPOT A RETROFIT INSULATION JOB
  • UFFI, EXTERIOR INSTALLATION SIGNS
  • UREA FORMALDEHYDE FOAM INSULATION, UFFI FAQs
  • UFFI REMOVAL PARTICLE SIZE HAZARDS
  • UFFI SHRINKAGE, THERMAL BYPASS LEAKS
  • UFFI SHRINKAGE LEAK IMPACT CALCULATION
  • UFFI INSULATION IMPACT ON HOME SALE PRICE
  • UFFI CLASS ACTION LAWSUIT, CANADA

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