Answers to Attic Questions #2

Look down the length of an unfinished attic.

This is part 2 of our series of attic Q and A's. Read part 1, here.

Q. I recently moved into a 77-year-old, one-story, ranch-style home. I began hearing creaking noises coming from the attic my first night there. Especially when it's windy outside, I'll hear popping, creaking wood noises, which last for a second or two and occur about five to 10 times a day. If I put my hand against a wall behind me in the bedroom, I can actually feel the vibration as it makes these popping and creaking noises.

A couple of people I've spoken to suggest it could be squirrels or other critters, but when I explain to them that this isn't a scratching, scurrying noise, they seem stumped (except for offering the usual, "Your house is haunted," jokes). Since moving in, I've discovered several renovations to this house that have been made in the last three quarters of a century. The most obvious one was the removal of an archway wall that had separated the living room from the dining room.

I entertained the idea that perhaps the owners from decades past had inadvertently knocked down crucial load-bearing walls, and that what I was hearing was my ceiling slowly collapsing, but then I began wondering whether there even are load-bearing walls in a one-story house?

A. In all probability, what you are experiencing is what happens in older homes: wood dries and shrinks and joints become loosened. All exterior walls are considered load bearing. Interior load bearing walls are easily identified in the attic. Check to see if there is an allowable span over it, if horizontal framing members end, join, or continue over it, or if roof braces end on it.

Q. I'm going to have to replace my Masonite siding with something similar soon. As a result, I will have lots and lots of 4x8 sheets of used Masonite. Some of them aren't in real bad shape, especially on one side.

I was thinking about using some of these in my attic to make a floor. I've been in my attic maybe five to 10 times to repair stuff or pull wires, and it's always hot in the summer. Crawling across on the joists (too short to stand) is NOT fun in the heat. If there was a floor there, it would be much easier, and I would get less insulation on myself.

The joists are 2x6 (maybe 8) and have blown insulation between them. I'm not sure how far apart they are. I'm guessing that I lose a lot of heating and cooling energy through the ceiling, especially in the summer. Can I just screw the 4x8 Masonite to the joists to make a floor? I would probably use very few screws, so I could remove it in case I needed to do any wiring.

A. If you can get the 4x8's up there, do it. Just put them down. Don't put a vapor barrier or anything else down; just leave it as it is. If you want to improve efficiency, replace the blown-in insulation with rolled-in insulation. It seems the blown-in insulation compresses or settles easily and loses its R value over time. I've also seen people insulate the underside of the roof decking with Styrofoam panels to help with summer heat gain.

Q. Our attic in our new house is below freezing in the winter. Is this normal? A furnace drainpipe froze up there and they had to put a heat tracer line on it. I'm concerned about the insulation, especially around the perimeter where I see a lot of daylight. The builder says the house has to breathe.

A. For sure, he is right; that is the way to go. A heater tape on the furnace flue pipe is OK. I don't know where you are, but an R-value of 38 or more in the ceilings is what you should have. The light from the overhang is good—it means the air can get up there and vent the attic. I like to tell people that the roof is just there to keep the rain and snow off the insulation. You might check to see if they have foam rafter vents you can put up before the insulation. With those, you can push the insulation up tight over the ceiling but still let the air up from the overhang vents.

Q. I just bought an old house, and I wanted to add more insulation in the attic. At the same time, I wanted to clean the soffit vents from inside. The gutter system doesn't seem too old, maybe 10 years, and the soffits outside are of vinyl, in which I can see the vents.

From inside, I could not see any light coming in from where the vents are, so I believe they need to be cleaned. I tried from inside the attic, but it is very difficult to reach that area to clean the vents, and instead of finding vinyl where the soffit is, I found wood. It seems that they put the more-modern, vinyl soffit over old wood. That means that those vents can't do their work.

Being a novice in all these things, I am not sure if this is the case, so I would appreciate any advice. Now, since it is the cold season and because the fascia has some 1/2-inch openings, I don't think that I have a ventilation problem, but I don't know how it will be in the summer.

A. You say you have modern, vinyl soffits, but then you say you can see 1/2-inch gap in the fascia. Whenever they install new soffits, whether vinyl or aluminum, the fascia gets capped with aluminum to cover the exposed edge.

As far as not seeing any light from inside the attic and finding wood, that is what almost everybody would find in an older home that's been re-sided or has new soffits or fascia. The original soffits in most homes were 1/4-inch plywood with metal vents installed every so often. Most people will install the new soffit right over top of all the original stuff, which is fine so long as the original vents are not painted shut or clogged up with layers of paint, and there are enough vents throughout the entire soffit to ensure adequate ventilation.

The best thing you can do at this point is to get any insulation pulled out from the area between the top plate of the wall where the rafters or trusses sit. This way, fresh air can get into your attic and help flush out the old stuff.

In my experience installing new siding or soffits, many homes do not have adequate vents in the wood soffits, so, before I install the new stuff, I'll usually rip down all the plywood soffits—especially if I cut some holes and find that area stuffed tight with insulation. If the airway between the top plate and rafters or trusses is open, I'll just cut some 12x24-inch holes every 3 or 4 feet to help the original soffit vents.

You have nothing out of the ordinary. I just hope there was adequate venting when they installed the new soffits.

On a side note, there is no opening under the eaves between the attic and the outdoors. There are no lookouts under the eaves. Having an opening would expose the attic to the outdoors without screening. The decorative soffits are just that, a way to decorate the rafter structure, which would otherwise be open and exposed.

Q. I am renovating a 100+-year-old Victorian "four square" with a walk-up attic. The existing attic ceiling is a plaster-and-lathe build. Behind it, there is an insulation material that looks and feels like wool or cotton and then the roof. Every resource I have looked at points to this substance being a rock wool or older fiberglass insulation blown in when a new roof was put on.

The only asbestos insulation I see mentioned anywhere is something called vermiculite, which is described as being granular, about the size of a pencil eraser, and generally used in the floor of an attic. It is obvious that is not what I have. Would it be safe to assume that my insulation is not composed of asbestos?

A. Older rock wool was suspected to cause cancer. While it reportedly did not contain asbestos, airborne fibers can pose a health risk. There is some research that links old, rock-wool insulation to cancer. All synthetic mineral fibers pose a health risk when inhaled, causing irritation of the eyes and upper respiratory system.

Fibers that can cause problems are asbestos, fiberglass, and rock wool. When they break down, they can float in the air, and the tiny, glassine threads can be inhaled. This may cause a problem in the lungs or elsewhere. The threads, once inhaled, can impale body tissue and travel throughout the body. They become sequestered by scar-tissue-like tumor formations and can cause breathing problems.

Tumors will be benign, but may eventually become cancerous since they will provide a place where the immune system is less effective and parasites, toxins, bacteria, etc. can gather. Insulation removers wear protective suits, gloves, masks, and respirators, take decontamination showers, and keep work areas well ventilated.

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