Jump to content

Insulation identification help


Peter Daly
 Share

Recommended Posts

I'm hoping someone can identify the insulation shown in the attached photo. It was placed in the walls in a building in San Francisco inabout 2000, presumably blown in behind the netting before the drywall was installed. It has a fine granular texture. The wall cavities have been repeatedly wetted since then due to poor window installation detailing and the lack of a weather-resistive barrier behind old redwood siding and the insulation is currently saturated and has compressed somewhat. I'm hoping to identify the brand and to determine if it can be salvaged in any way or whether I should advise the owner to remove and replace it.

Thanks

Download Attachment: icon_photo.gif DSCN0019.JPG

864.27 KB

Link to comment
Share on other sites

I don't think it's Icynene pour fill or uffi. It looks like it was placed behind a netting while the walls were open. Right now, it has very little if any cohesion. I can pull it out in handfulls and has the consistency of a fine sand. I'm sure that the insulation was installed when the building was remodeled in 2000. At the time, it was written up as one of the most important "green" projects in the city up to that time so I'm thinking that the insulation might be a product that was relatively new at the time.

Link to comment
Share on other sites

Could be an early soy based application; the early stuff sort of "sandy". Pretty rare though; not many soy based applications out there to compare to.

Did you taste it? The soy products I have tasted are very similar to blown in cellulose.[:-yuck]

If it is a "green" house, it probably is some sort of organic material, all the more reason to pull it out.

Anybody run into the recycled blue jean insulation yet?

Link to comment
Share on other sites

I'm confused. It LOOKS as if it is a granular loose-fill material that has merely become clumpy through exposure to moisture. Is that an accurate assessment or not?

Yes I think that's accurate. The only alternative I can think of is that it's a foam product that has somehow broken down completely and that just doesn't seem likely
Link to comment
Share on other sites

Well, it sure looks like Perlite, blue or not, having poured 1000s of bags down block wall. The size seems about right and Perlite is a decent insulation. We were pouring it down school walls in the 70's. I imagine the blue color could have been taken on by what moisture picked up from other materials along the way? Is it wispy light, as if you could accidentally inhale it? Perlite was light as a feather, when dry, and swirled all around us in the air as we poured - so light it almost appeared to defy gravity. One had to be patient in pouring so as not to overwhelm a block core and waste a ton of it. Yet, if there was a hole, of any size, down at the bottom of the wall, it would all sift out in an hour or so like sand in a sand clock - funny stuff...

Link to comment
Share on other sites

Well, it sure looks like Perlite, blue or not, having poured 1000s of bags down block wall. The size seems about right and Perlite is a decent insulation. We were pouring it down school walls in the 70's. I imagine the blue color could have been taken on by what moisture picked up from other materials along the way? Is it wispy light, as if you could accidentally inhale it? Perlite was light as a feather, when dry, and swirled all around us in the air as we poured - so light it almost appeared to defy gravity. One had to be patient in pouring so as not to overwhelm a block core and see waste a on of it. Yet, if there was a hole, of any size, down at the bottom of the wall, it would all sift you in an hour or so like sand in a sand clock - funny stuff...

Seems like it may well be Perlite. So the question is, having become saturated is it in any way feasible leave the insulation in place and let it dry assuming that the water intrusion issues can be dealt with successfully?
Link to comment
Share on other sites

I'd remove it, especially if the walls are opened up like your pic. Perlite is used as an additive to potting soil because it readily absorbs moisture, holds it, and releases it slowly as the surrounding material dries out. Pretty lousy qualities for insulation in a wood framed wall, especially one that leaks.

Tom

Link to comment
Share on other sites

I'd remove it, especially if the walls are opened up like your pic. Perlite is used as an additive to potting soil because it readily absorbs moisture, holds it, and releases it slowly as the surrounding material dries out. Pretty lousy qualities for insulation in a wood framed wall, especially one that leaks.

I have the opposite opinion. I like insulations that act like moisture banks far better than non absorbent insulations like fiberglass for existing structures.

Link to comment
Share on other sites

I'd remove it, especially if the walls are opened up like your pic. Perlite is used as an additive to potting soil because it readily absorbs moisture, holds it, and releases it slowly as the surrounding material dries out. Pretty lousy qualities for insulation in a wood framed wall, especially one that leaks.

I have the opposite opinion. I like insulations that act like moisture banks far better than non absorbent insulations like fiberglass for existing structures.

So do you think that this insulation which has been saturated can be dried after the water intrusion issues have been resolved and be effectively left in place? Even if it could be, there are still extensive void areas in the wall where the insulation has settled or been compacted through the wetting process.
Link to comment
Share on other sites

I'd remove it, especially if the walls are opened up like your pic. Perlite is used as an additive to potting soil because it readily absorbs moisture, holds it, and releases it slowly as the surrounding material dries out. Pretty lousy qualities for insulation in a wood framed wall, especially one that leaks.

I have the opposite opinion. I like insulations that act like moisture banks far better than non absorbent insulations like fiberglass for existing structures.

So do you think that this insulation which has been saturated can be dried after the water intrusion issues have been resolved and be effectively left in place? Even if it could be, there are still extensive void areas in the wall where the insulation has settled or been compacted through the wetting process.

Not taking into account what Chad or Tom have said, and merely addressing your question regarding moisture, I would guess that it would dry and be fine, because it is apparently an expanded (possibly through a heating process) stone - pretty inert material. Unless someone can make a case to the contrary My guess is that it would be find.

I have mixed emotions about the pros and cons of Perlite and moisture: When I was still doing disaster restoration work, it was interesting to observe that typically moister would dribble right on down through fiberglass batt insulation with very little consequence, due to the lack of density of the insulation, until it hit the sill plate, where it finally then became a problem. Perlite, on the other hand is also used mixed with potting soils for either moisture retention or dispersion (not sure which). I can see Chad's point if the Perlite prevented the moisture from pooling and slowly promoted evaporation, but can adequate evaporation occur in a frame wall system? It's an interesting concept which is worth discussion if anyone had some good input.

Link to comment
Share on other sites

I'd remove it, especially if the walls are opened up like your pic. Perlite is used as an additive to potting soil because it readily absorbs moisture, holds it, and releases it slowly as the surrounding material dries out. Pretty lousy qualities for insulation in a wood framed wall, especially one that leaks.

I have the opposite opinion. I like insulations that act like moisture banks far better than non absorbent insulations like fiberglass for existing structures.

The 'banking' properties of perlite much more closely match those of CMU than wood framing materials. Managing the moisture within a wall system is far more sensible approach than attempting to prevent it altogether, but the materials in that system should dry at similar rates. The pics in the OP clearly show what happens when they don't.

Perlite in a wood frame wall fails just as miserably as fiberglass, but for different reasons.

Tom

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...