Help!! My house is contaminated with fiberglass - not from the air vents -- but pushed through the light fixtures. Caused by negative air pressure in the attic after new roof. How do I rid the air of the fiberglass? I have cleaned for 6 weeks now and still there is fiberglass settling on the furniture, beds, food, toilet -- you name it. I'm an old woman and I need help desperately. What do I do??

jaws51

Please discuss the work you had done. You said "after a new roof" Does that mean just new shingles or does it mean that new roof decking was put on? Was any insulation put add or put in?

You do not have a negative air pressure in the attic. That would mean a vacuum.

What it sounds like is that the attic vents were sealed and the air in the attic expands as it is heated during the day. With no place to go it escapes through the cracks between the electrical boxes and the ceiling drywall, carring particles insulation with it.

Again, please tell us exactly what work was done to the roof and attic.

Harold hit all the points but I can't rate him until I spread more around. I will be interested how this plays out, can't really picture the attic becoming so pressurized that it vents into the home. Is this blown in loose insulation, fiber glass batts or rolls?

The roof decking was not replaced. I was told this "negative air" term by two different A/C techs who checked the ducts. I have fiberglass in all globe light fixtures. I am referring to blown-in insulation that was all ready in the attic. I have not added any since the new roof.

jaws51

I have no idea what the A/C tech could have meant unless it is just a fancy way of saying that the air in the attic is getting hot and expanding and pushing through the ceiling fixtures. This can only happen if you don't have proper venting in the attic.

Did the roofers change your attic venting?
What type of attic venting do you have, gable vents, vents under the eves, ridge vent? Willing to bet you had a ridge vent and roofers changed it or failed to install an new ridge vent.

I agree with hk.

Negative air is used for removing contaminates from an area. This is done by sealing off area and exhausting air to outside. By doing this, u will be drawing air from surrounding areas to fill void made by exhaust not pushing air into surrounding area.

If ridge vent was installed with new roof, it will be slightly higher then ridge. Vent will start about 2' from gable end of house.

Chuck

Quote:

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Originally Posted by jaws51

The roof decking was not replaced. I was told this "negative air" term by two different A/C techs who checked the ducts. I have fiberglass in all globe light fixtures. I am referring to blown-in insulation that was all ready in the attic. I have not added any since the new roof.

jaws51

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I think they mean inside your house pres is negative( low pressure), so the dust from the attic( high pres) is going ( suck/ push) through the fixtures... it also cause by the attic fan installed backward or leaking supply air from your ac system. Did the 2 ac techs verified all your duct are properly connect?

Finally, someone who knows what this old woman is trying to say. Thank you. Both A/C men found no hole or loose fitting in any of the attic duct work or in the A/C unit itself. I have a cathedral ceiling in my kitchen and den. There are two globe light fixtures that look black inside. I have removed and cleaned the other globe fixtures and cleaned them. I have vacuumed all furniture, blinds, floor, etc. I have thrown away bedspreads, clothes, etc. I have removed all silk flower arrangements, pictures, etc. Still the fiberglass settles on the furniture. Please, please what other options do I have? The settling is far better than it was, but cleaning has just about put me in the grave. I've called companies to help me and they don't even return my calls.

The fiberglass is now hanging from the air vents. I clean and I clean. Any suggestion would be greatly appreciated.

You need to test to find out how the air is come in through the fixtures. You could use cig or incense as smoke. Test it with the ac off and running, cover off the air vent nearby so it won't blow toward the test area and remove the fixture's cover. You should check into what others have said

Can you give me the source of reference material that provides information about this negative air pressure?

Sorry I that don't have the information you are asking for . It work exactly like a vacuum. You should have someone to check to make sure your attic have proper ventilation. If the problem couldnot be located, you need to smoke test the air flow in your house.