Replace contaminated attic insulation?

6 months ago

last modified: 6 months ago

First, I welcome suggestions on categories for this message. Nothing I can find seems to fit.

I'm seeking expert advice on a rat contamination situation.

I'm living in a single-story house with a membrane roof of unknown age. (It was here when I bought the house in 2009.) The roof seems to be in good condition so far, but it needs to be replaced because some parts of the underlayment have deteriorated. The roof is dangerous to walk on.

The roof pitch is shallow, making access to the attic difficult. The attic is filled with blow-in insulation, but at one point it was accessible to rats and raccoons, which contaminated the insulation extensively.

I'm having the roof replaced during the dry season this spring or summer. My contractor suggested that I have the attic cleaned out and re-insulated while the roof is open. Estimated added cost: about $6700. That's a significant fraction of the cost of the roof itself. If I'm going to do it I should do it now, because once the new roof is on, access will be much more difficult.

On one hand, I think, "It's filthy disgusting up there--do it!" On the other hand, I think, "I never go up there, so what's the difference?"

What say you? Is an attic heavily contaminated with rat feces a health hazard, or is it unimportant because it's sealed off from the house? Is this work worth $6700, or is it pointless?

Sort by:Oldest

Comments (7)

klem1
6 months ago
I agree it sounds disgusting but in truth many if not most older attics have the same or worse in them. If you don't detect odors I wouldn't worry about it. I would check to be certain ceiling fixtures, hvac vents and other penetrations are well sealed (as much for protection from airborne insulation and dust as the animal droppings).
User
6 months ago
This is the time to do it. Hire professionals do remove as they come garbed and masked for the task. They will also clean the walls and floor boards. When we bought this house, the insulation was disgusting. You got a good price...we paid $20,000 and our contractor took the walls down to the studs.
Related Professionals
Dayton Home Remodeling · Gary Home Remodeling · Pueblo Home Remodeling · Hays General Contractors · Wilmington General Contractors · Marietta General Contractors · Lufkin General Contractors · Elizabethtown Bathroom Remodelers · Hackettstown Home Remodeling · Rapid City Home Remodeling · Montréal Home Remodeling · Marquette Home Builders · Madison Kitchen & Bathroom Designers · Williamsburg Kitchen & Bathroom Designers · Worcester Kitchen & Bathroom Designers
central_valley
Original Author
6 months ago
@judy_graham46 At this point I'm inclined to do it.

I'm inclined to think I'm getting a fair price, but not as great a one as you suggest. "Our contractor took the walls down to the studs" implies that you had walls to take down to the studs, in other words, a finished attic. I don't. There are no walls; there are no studs. The rafters meet the walls at the attic's floor level. Under the roof ridge, you kneel. Elsewhere, you crawl.
cat_ky
6 months ago
All the 2x lumber up there is actually called studs. It is the structure that holds your house up.
klem1
6 months ago
All the 2x lumber up there is actually called studs. It is the structure that holds your house up.

Most interesting cat_ky , it's not often we see anyone on this forum with this type knowledge so will you please tell us more? Where are rafters and ceiling joists located in single story homes? What is the lumber called that drywall is fastened to on walls?
central_valley
Original Author
6 months ago
@cat_ky Um, no. A wall's vertical members are called studs. The horizontal members at the top and bottom of the wall are the top and bottom plate. Short horizontal members between studs are blocks. Horizontal parts that support a floor or ceiling are joists. Parts that run up the slope of a roof are rafters, and the part that supports the ridgeline is the peak.

Obviously I'm simplifying things. There are a lot more names to know if you want to have windows, for example. If you google "compound roof framing parts diagram" you'll find pictures and text that explain a lot of this stuff.
apple_pie_order
5 months ago
Clear all the blown-in insulation when you get the new roof. When choosing new insulation, consider that it is much easier to find pest problems (such as a dead rat) by lifting up insulation batts than it is by shoveling up blown-in insulation. Do everything possible to block entry by rats and raccoons.