3

I've had occasion to get up in the attic of my (new, to me) house recently. There is what appears to be dirt all over everything up there, with actual accumulation in places.

This is a 2-story 1964 stick built stucco exterior home built over a dirt crawl space. There is no plastic or anything over top of the dirt. The walls are completely uninsulated.

The only possible way I can conceive of dirt getting into the attic is stack effect sucking dirt out of the crawlspace and up the inside of the walls where it then settles out in the attic.

Anybody ever heard of something like this or can identify another possible source for dirt in an attic?

  • It's conceivable that during the build process that they left dirt there and that it spreads with airflow. – DMoore Oct 21 '14 at 21:05
  • 1
    What is the type of ventilation for the attic? Gable vents? Soffits? Ridge vent? – treeNinja Oct 21 '14 at 21:05
  • @treeNinja: Dormer vents – bobfandango Oct 21 '14 at 21:10
  • @DMoore: I suppose it is possible that the building materials could have been quite filthy at construction. – bobfandango Oct 21 '14 at 21:11
  • What kind of roof? Could it be tar instead of dirt? – Bryce Oct 24 '14 at 8:15
2

Subterranean termites build mud tunnels from dirt that they bring up from the ground. Tunnels going from crawlspace to attic is common. Most termite guys will destroy the tunnels after treating the area and not bother to clean up the dirt. Not saying this is the source (I'm not a termite inspector) but something to consider

1

I can think of three reasons.

  1. Dust, like you mentioned, but coming from anywhere (e.g. soffit vents), not just the crawlspace
  2. Debris from the the last roofing.
  3. Termite turds. Look up pictures of termite pellets.

Is like dust? Sandy? Gravelly?

  • There are some termite pellets, but these are visually quite distinct from the "dirt" as I'm calling it, and there is substantially less pellets than dirt. – bobfandango Oct 21 '14 at 21:14
  • Concerning termites, subterranean termites build mud tunnels from dirt that they bring up from the ground. Tunnels going from crawlspace to attic is common. Most termite guys will destroy the tunnels after treating the area. Not saying this is the source (I'm not a termite inspector) but something to consider. – diceless Oct 21 '14 at 21:31
  • Offhand, I'd go with roofing debris. I'd be more surprised to find a 'clean' attic. – Mazura Oct 22 '14 at 1:50
  • @diceless Re-write your comment as an answer, and I will accept it. I crawled around under the house for a bit yesterday, and found old mud tunnels. I then crawled back into the attic (not easy with a 3/12 pitch) with better light and was able to find tell tale signs of old tunnels once I looked carefully in all the nooks. No doubt they were knocked down after some prior fumigation so you'd know if new tunnels came in.... – bobfandango Oct 23 '14 at 22:44
0

A couple of thoughts...

  1. If there are holes in the ceiling of the second floor then air can be flowing up into the attic. Over years this can create a fair amount of dirt/dust.

  2. If you have an automatic fan to ventilate the attic this could be pulling dirty air into the attic through the soffits. Sounds like you do not, but suggesting...

  3. It may not be dirt and could be something else. When I moved into my home we had a minor mold issue in our attic. It looked like dirt but it was mold. We had to remove the top layer of insulation and improve the attic ventilation among other things.

  4. If you have an AC system maybe the air before it hits the filter is also exhausting out someplace.

Do the areas of high dust provide any sort of pattern? Can you identify those areas of higher dirt and identify any reason they might get more? Near a bathroom fan? a hole in the roof that you assume or thing is sealed but might have a small opening etc.?

0

It could not be dirt at all. If you see discoloration on your insulation that could indicate a high amount of airflow through the space over time.

  • Thanks, but this house is in Southern California. It has no insulation of any kind. – bobfandango Oct 24 '14 at 15:51

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.