Insulating attic floor

[joesxm3]

I made the first major excursion into the attic for the insulation project tonight.

I cut another 16 inch by 24 inch hole in the wall that separates the original house from the addition and moved in several small pieces of plywood that I had lying around. I made a crawl zone almost to the end of the addition.

I have lots of wire running around and I am hoping to be able to remove some of it because it is probably obsolete.

One two wire pair is black and connects to a "splitter" labeled UHF/VHF/FM. I am assuming that this is some sort of antenna that no longer exists.

?? = Another wire is like a ribbon and appears to have four our five wires side by side in it. Any idea what this might be?

There is lots of white wire that I think is called "romax". This seems to be the main power wire and I have tracked it to the ceiling light in my bedroom and over to the wall where it goes down, presumably to feed the wall outlets. I plan to watch out for this wire.

We had an electrical survey at work yesterday and the electrician told me that it is ok to put insulation over the romax wire. Do you agree?

I bought the head lamp that SamClem mentioned, a respirator with two canisters that handles N95 and organic vapor and some chemical goggles that fit around my eye glasses. I took a picture of me all suited up, but I am not sure how to put it into my post.

I lifted up the existing batt insulation and there is two types. The top layer has a metalic vapor barrier and is about 3 inches thick. It seems in relatively good condition.

The vapor barrier separates easily from the insulation so I can convert it to unfaced insulation if I want to. I am considering reusing it.

The lower layer has a paper vapor barrier. This is only one inch thick. I had never heard of such thin insulation. I wonder if it used to be three inch and now is degraded from 25 years with the double vapor barrier. I think that this layer will be discarded.

The lower layer has the paper stapled to the joists. The edges lift up where the staples are leaving a little gap which I think is not good.

?? = Does a vapor barrier have to be only one thing or could I put more than one thing down for the vapor barrier. For example, would it be ok to leave the original kraft paper and then put the new insulation with its own kraft paper directly on top? Or would it be ok to get some new vapor barrier material and lay it between the joists and then lay the new
insulation with the kraft paper on top of it.

On one hand it seems like the two layers immediately on top of each other would catch some leaks. On the other hand I wonder if there still would be condensation between the two pieces.

A smart guy at work told me that he made an insulated cover for his attic hatch and he said that he got some metalic thin insulation that he put on the bottom and then he put some foam panels on top. He said that the metalic insulation would immediately reflect infrared radiation while the foam would block normal heat transfer. Does this make sense?

That is what gave me the idea of possibly getting some metalic vapor barrier and putting it down first and then puting the kraft-faced batts on top. I suppose if I wanted to do it that way I should have gotten unfaced six inch thick batts so I would not be doubling up on the vapor barrier (too late now for that).

Since I have already purchased 10 bundles of kraft-faced batts I am committed to using them.

If there is negative or no benefit to trying to double the vapor barrier I will just lift up the original kraft paper and lay in the new batts.

I explored the edge where the outside wall meets the attic. There is a small area with no insulation about six inches deep directly against the wall. The bottom of this seems to be a 2x4 which I assume is the top of the wall framing. There is a 1/32 inch gap on the inside side of the 2/4.

?? = Should I caulk the 1/32 inch gap? Should I put insulation into the 4 inch area along the wall? I do not have soffits so there are no soffit vents to block. My neighbor warned me not to go to close to the edges because he said I want to have air moving up inside the wall for ventilation purposes. I am not sure if he was correct.

When the moisture condenses inside the wall on the vapor barrier which is directly against the inside sheet rock, does it get eliminated by rising up through the wall insulation and out the top?

My protective equipment worked pretty well so far, but I did bang the top of my head on one nail. I had been looking for a little hard hat that was sort of like a baseball cap but did not find one. I think I may cut a cheap aluminum pie plate and make a little skull protector to wear under my cap just in case.

Sorry for such a long post - so much to report - so much to wonder about.

Thanks again and in advance for all the help.

[samclem]

I hope you don't mind if I chime in again.

Quote:

Originally Posted by joesxm ?? = Another wire is like a ribbon and appears to have four our five wires side by side in it. Any idea what this might be?

Hmmm. I'm not familiar with any sort of 4-5 conductor cable used in homes that is a flat ribbon. Most of these small 4-5 wire cables are either for telephones or thermostats (from the thermostat to the furnace/boiler/AC unit)

Quote:

Originally Posted by joesxm There is lots of white wire that I think is called "romax". This seems to be the main power wire and I have tracked it to the ceiling light in my bedroom and over to the wall where it goes down, presumably to feed the wall outlets. I plan to watch out for this wire.

. Yep, probably Romex. Today the white stuff is normally for 20 amp circuits, the white stuff is for 15 amp circuits, but that might not have been the standard in the past.

Quote:

Originally Posted by joesxm We had an electrical survey at work yesterday and the electrician told me that it is ok to put insulation over the romax wire. Do you agree?

. Putting insulation (foam, fiberglass, cellulose) in contact with the cable is allowed by code. It is okay to do it, but think ahead and if you might someday need to access the wire, it might be best not to bury it under insulation.

Quote:

Originally Posted by joesxm ?? = Does a vapor barrier have to be only one thing or could I put more than one thing down for the vapor barrier. For example, would it be ok to leave the original kraft paper and then put the new insulation with its own kraft paper directly on top? Or would it be ok to get some new vapor barrier material and lay it between the joists and then lay the new insulation with the kraft paper on top of it. On one hand it seems like the two layers immediately on top of each other would catch some leaks. On the other hand I wonder if there still would be condensation between the two pieces.

Are we in the attic now, or still inthe crawlspace?

There should not be condensation (liquid water) anywhere if everything is working right. Your goal is to keep the water vapor above the dewpoint. By putting the vapor barrier on the "warm side" (next to your floor and next to your ceiling, with insulation outide to keep in the heat) you are stopping the flow of moisture out of your house at a point where it should always be above the dew point (thus remaining a gas, not condensing to a liquid). In this case, I don't think it is likely to cause much problem having the two vapor barriers right up against each other with the insulation on the outside, but two "partially intact" barriers won't be as effective as a single intact, well installed VB. I'd probably tear out the top one, and install a good one before adding the insulation.

Quote:

Originally Posted by joesxm A smart guy at work told me that he made an insulated cover for his attic hatch and he said that he got some metalic thin insulation that he put on the bottom and then he put some foam panels on top. He said that the metalic insulation would immediately reflect infrared radiation while the foam would block normal heat transfer. Does this make sense? That is what gave me the idea of possibly getting some metalic vapor barrier and putting it down first and then puting the kraft-faced batts on top.

This reflective metalic stuff is caled a "radiant barrier". It does work to block the flow of heat that occurs by IR radiation, but it is commonly mis-used and there are a lot of scammers out there. The bottom line s that these barriers need a minimum of 3/4" air gap on at least one side to be effective. If the barrier is touching anything on both sides (including insulation) then the primary heat transfer mode is by conduction, not radiation, and the barrier is worthless. Imagine it this way: you are in a very cold room right beside a red-hot stove. You can feel the heat radiating from the stove very well, because it is radiating directly (as long-wave IR "light"). If you put even a thin piece of aluminum foil between yourself and the stove, it would do a very good job of blocking that heat transfer. On the other hand, it you put the foil right on the stove and touched the foil firmly, it would not do a good job of blocking the heat transfer, and you'd get a nasty burn for your trouble. It is the same with these radiant barriers--they only work with an air gap. Your friend's attic hatch cap might be effective if it has a gap, but if it doesnt he would have been better off to spend his money on another 1/2" of foam.

Quote:

Originally Posted by joesxm I explored the edge where the outside wall meets the attic. There is a small area with no insulation about six inches deep directly against the wall. The bottom of this seems to be a 2x4 which I assume is the top of the wall framing. There is a 1/32 inch gap on the inside side of the 2/4. ?? = Should I caulk the 1/32 inch gap? Should I put insulation into the 4 inch area along the wall? I do not have soffits so there are no soffit vents to block. My neighbor warned me not to go to close to the edges because he said I want to have air moving up inside the wall for ventilation purposes. I am not sure if he was correct. When the moisture condenses inside the wall on the vapor barrier which is directly against the inside sheet rock, does it get eliminated by rising up through the wall insulation and out the top?

There should be condensation of water in the wall. The warm, moisture-laden air (or the water vapor itself passing through the materials) inside your home is prevented from entering the stud bay by the vapor barrier placed right against the wall. The vapor never gets cool enough to condense. If it did, you'd have mold and other problems.
I'm having a hard time visualizing the construction at the top of your walls. It's not like what I've seen. Does your house have any overhangs or eaves at all, or does the roof end right at the wall (Cape Cod style?)

[joesxm3]

SamClem - I was hoping you would reply and appreciate your time since you seem to be busy. I saw the great post you just did to help with the wet basement.

Yes, my question about the double vapor barrier pertained to the attic. Did I understand correctly that you feel the optimal choice would be to remove the old paper barrier adn get some separate vapor barrier material and install it in between the attic floor joists and then put my kraft-faced batts in between the joist with the kraft paper down? And the second best choice was to remove the old paper barrier and just put the kraft-faced batts paper down between the joists?

The wall I was talking about was on the gable end of the attic, not on the roof side. It seems that the second floor wall was made by building a rectangle out of two by fours and then putting the wall studs in. This would have then been raised to vertical and the attic floor joists put on top. The floor joists are parallel to the gable walls, same as the 2x6's making up the roof arch. It seems that the last floor joist is right next to the 2x4 that makes the top of the second floor wall. There is plywood nailed to the outside of the wall frames.

This results in a space next to the gable wall made up of the 2x6 joist on the inside (4 inches showing), the 2x4 top of the wall as the bottom of the space (4 inches wide) and the exterior plywood on the outside of the space. This is a 4 inch deep, 4 inch tall, 22 foot long cavity at the gable edge of the attic floor. The second floor wall insulation would be inside spaces bounded by 2x4's in the wall. We cut a small hole once and it looks like we have minimal 4 inch insulation in the walls.

When the windows and siding were done, they brought in an insulation contractor and he decided that it would be too hard to blow into the wall cavities and adding foam board under the siding would make the siding stick out past the windows. They said the best thing would be to blow insulation into the attic but they wanted me to remove the old insulation first and the project drifted into never never land. That was around 2002.

I have not yet crawled down to the area where the roof meets the wall of the house.

However, there is no overhang at the point where the attic meets the second floor. In the front of the house there is a 9 inch or 1 foot overhang between the first and second floors. This is what would have been the soffit for the attic to have soffit vents, but it is an entire floor too low.

I had considered trying to push some PVC pipe up from below to make a nine foot soffit vent, but I think that I would hit the wall insulation and I am suspecting that there will also be a 2x4 across the top of the wall cavity that I would have to cut holes in.

The back of the house has no overhang at all.

I will know better tomorrow morning, but I am guessing that the second floor wall along the roof sides of the attic is built like the gable side with a 2x4 across the top of the wall cavity. I guess that the roof rafters must be cut at an angle on their ends and just sit on top of the second floor wall frame without sticking out past it.

I read more about ventilation and now think I have a possibly conflicting mix of ventilation systems.

Originally the attic had two rectangle gable vents with louvers and screens. From reading this seems to be about one square foot of effective ventilation per vent taking the louver blocking into account. There was an exhaust fan on on gable. There was the interior wall blocking the two gable vents and only having the 14 inch by 24 inch opening cut in the wall.

When I bought the house that setup had roasted the roof shingles.
I had the roof replaced and the contractor insisted on putting in a ridge vent across the whole top of the attic. When I pointed out that there were no soffit vents they sort of shrugged and made some comments that the exhaust fan on the gable would probably end up sucking air in through the ridge vent instead of the other way around.

Having read a little about ventilation it now seems that I want to be taking in air from the bottom and having it go out the top.

I plan to cut several openings in the interior wall to increase the air flow. When I cut the one additional opening tonight I could see a large increase in the breeze between the two gable vents.

I think I should get rid of the gable exhaust fan and use the two gable vents as air intakes rather than trying to exhaust through one. This would give some hope of air coming in half-way down the gable wall and going out through the ridge vents.

I also think that I should get an exhaust fan that mounts in the roof to supplement the ridge vent.

Since the exhaust fan needs air intake I think I need to make some more vents. I am considering getting two more square gable vents and mounting them in the gable wall on one end of the house as close to the floor as possible. One end is two stories while the other end is three stories due to a garage at the cellar level with a sunken driveway. I am ok with doing two stories on the ladder but three is pushing it for me.

Based on what I said about the wall cavities having a two by four across the top I would imagine that there is not a lot of air flow up the wall cavity.

What I was asking about is whether I should caulk the crack between the wall top 2x4 and the attic floor joist next to it and whether I should put some fiberglass insulation into the 4inch by 4 inch by 22 feet space next to the wall.

A similar question would apply to the roof side walls once I look at them.

Thanks for taking the time to help me so much.

This project is very educational and I seem to be making massive strides at being able to do stuff. Last year the idea of installing the roof exhaust fan terrified me, but now it seems just like cutting a little plywood and sticking in a unit. I still may have the local electrician do the wiring, but the electrician at work yesterday convinced me that I can change the light switch at the top of my cellar stairs so I may become a wiring guy too someday soon.

One question with regard to cutting the vents in the wall. I have vinyl siding and I will have to cut a square in the siding for the vents. Would I have to get some sort of edge piece for the siding or do you think that the cut siding edges will just go under the vent exterior frame?

[travelover]

Quote:

Originally Posted by samclem .............Hmmm. I'm not familiar with any sort of 4-5 conductor cable used in homes that is a flat ribbon. Most of these small 4-5 wire cables are either for telephones or thermostats (from the thermostat to the furnace/boiler/AC unit) ...............

I found a similar wire in my attic. It used to control the TV antenna rotation.

[samclem]

joesxm,
Thanks. I'm starting to see your situation more clearly.

Quote:

Originally Posted by joesxm Did I understand correctly that you feel the optimal choice would be to remove the old paper barrier adn get some separate vapor barrier material and install it in between the attic floor joists and then put my kraft-faced batts in between the joist with the kraft paper down? And the second best choice was to remove the old paper barrier and just put the kraft-faced batts paper down between the joists?

There are several satisfactory answers. While it is important to impede (not necessarily stop) the flow of moisture through materials, stopping the mass flow of air (through cracks, holes, etc) around materials is much more important. In your shoes, I'd probably lift out the old insulation in a single bay, then (with a good ability to see the roof framing/ceiling interface now that the insulation was out of the way) carefully caulk all seams, cracks, holes that could allow air into the attic, then I would probably put in new kraft-paper backed insulation (paper side down, as you know) into the bays. (Alternatives to the kraft-paper --you could paint either the top or the room-side of the ceiling with 2 coats of Zinser BIN, or you could lay in a separate vapor barrier--even plastic. The kraft-paper-backed insulation is probably easiest). At that point, I'd probably tear the VB off the old insulation and put it back on top of the new insulation I'd just put in, then move on to the next bay. When all the bays are done, lay additional unfaced insulation 90 degrees to the joists (again re-using any servicable insulation left over from the original stuff.) As mentioned previosuly, I'd actually blow cellulose over the fiberglass, but I understand your decision.

Quote:

Originally Posted by joesxm This is a 4 inch deep, 4 inch tall, 22 foot long cavity at the gable edge of the attic floor.

I understand now. Just push some insulation down there (start with a piece with VB at the very bottom) to fill the gap. Get busy with the caulk here--you're likely to find cracks that let air go from the inside of your home into the attic where all this framing comes together.

Quote:

Originally Posted by joesxm When the windows and siding were done, they brought in an insulation contractor and he decided that it would be too hard to blow into the wall cavities and adding foam board under the siding would make the siding stick out past the windows. They said the best thing would be to blow insulation into the attic but they wanted me to remove the old insulation first and the project drifted into never never land. That was around 2002.

If you saw 3-4" of fiberglass insulation in your walls when you looked , don't spend the money to have anything else blown in or inserted into the stud bays. Be glad you have insulation in the walls at all. I can't remember if you mentioned the age of your home, but wall insulation wasn't standard in some areas until well after WW II. If there are spots without any wall insulation, it would be worth exploring the options for inserting some (dense-pack cellulose, icythene, etc), but if you've already got 3-4" of fiberglass it won't help much (aing more now is an "iffy" process--gaps are common since the contractor can't see what is actually hapening in the bay as he fills it, it compresses your existing insulation making it less effective, etc. Your money is best spent elsewhere).

Quote:

Originally Posted by joesxm I had considered trying to push some PVC pipe up from below to make a nine foot soffit vent, but I think that I would hit the wall insulation and I am suspecting that there will also be a 2x4 across the top of the wall cavity that I would have to cut holes in.

That's the kind of (whacky? innovative?) idea I would have considered, too. It's a good thing you rejected it. Aside from the pipe being too small to do much good, it also would have introduced a cold "line" running up your wall. On the inside of the house this would be below dew point on cold days, and even if it never produced visible condensation, it would have quickly produced a dark line where dust was attracted to the moisture. This same thing happens with metal framing in walls sometimes.

It's really too bad that you couldn't get just 1/2" of foam put on the outside when the siding was done (I know I hit this before-sorry). What's done is done, but it would have significantly reduced heat loss through the wood studs, added a little to the R-value of the inter-stud spaces, ad also reduced air leaks through the wall. Maybe next time.

Quote:

Originally Posted by joesxm I read more about ventilation and now think I have a possibly conflicting mix of ventilation systems.

I think you may be right. I didn't know you had a ridge vent, too. It sounds like all your ventilation is up high, with no good way to get replacement cool air into your attic. This is causing your attic to be hotter in the summer and increasing the possibilty of moisture problems in winter.

Quote:

Originally Posted by joesxm I think I should get rid of the gable exhaust fan and use the two gable vents as air intakes rather than trying to exhaust through one.

If you've got a full-length ridge vent along the top of your house and these gable vents, you don't need any more vents to let air out of your attic. You definitely don't need power ventilation-it won't improve the situation (the negative pressure from the exhast fan will just draw fresh air in through the nearest high vent, but you want the air to be going out of the high vents.)

Quote:

Originally Posted by joesxm Since the exhaust fan needs air intake I think I need to make some more vents.

Absolutely. It sounds like the very biggest issue in your attic ventilation "challenge" is admitting outside replacement air into the attic. Again, you've got plenty of "out" area up high, you need some "in" vent area down low. A series of vents at the base of the gable wall might be the best option, though I think you'd be best off if you can get this cool air into the interior of the attic (again, maybe using an easily-built plenum leading from the low vents on the gable wall to the interior of the attic.) Just installing the vents low on the gable wall will result in the air moving directly up the gable wall and out, without intermingling with the warm, moisture-laden air in the rest of the attic. I don't think that there's likely any replacement air being routed up your exterior walls and into the attic, but let us know what you find when you explore the roof-edge portion of the attic. Or, look at the base of the walls outside--is there any evident place where air is supposed to be admitted?

Quote:

Originally Posted by joesxm One question with regard to cutting the vents in the wall. I have vinyl siding and I will have to cut a square in the siding for the vents. Would I have to get some sort of edge piece for the siding or do you think that the cut siding edges will just go under the vent exterior frame?

It depends on the vent frame you buy. It might have a lip to accommodate vinyl siding, and that's the kind you want to buy. BTW, a good way to cut the vinyl siding is with a circular saw, but flip the blade backward so that the teeth don't "bite" into the vinyl. Wear eye protection, and don't try this when the vinyl is very cold/brittle. It worked well for me.

One other question-is there any chance you might want to make a small usable room in this attic? Maybe a study or other place with heat? I didn't think so based on your other comments, but if there is then we would do everything differently regarding insulation and ventilation (i.e. it would make more sense to approach this as a type of cathedral ceiling, don't bother with ventilation, and insulate the underside of the roof decking instead of the attic floor).

[joesxm3]

I just finished an hour and a half and removed the insulation from the 10 joist bays on one half of the addition. I found three bays with mouse feces and one that looked more like the bottom of my cat's litter box.

It is nearly impossible to get to the roof edge side because of the way that the rafters meet the 2x4's that are the top of the second floor wall. From what I can tell the rafter comes down alongside the floor joist and then is cut at an angle and sits on top of the 2x4. I should have paid more attention but I think that the extra 2 inches of the 2x6 rafter is on the inside of the 2x4 rather than hanging over the outside, but I will have to double check.

I now realize I did not pay enough attention, so some of this may contradict but there is a 2x4 that has the 2inch part down and the 4inch part vertical that goes around the outside part of the framing. It may be nailed to the ends of the floor joists.

The net result is that near the edge the bottom is either the 2x4 from the second floor wall or the sheetrock sitting on top of the 2x4 and the outside wall is the 2x4 that is on edge going around the outside like a lip on a tray.

There is an opening about half an inch where the two 2x4's come near each other.

BTW - the head lamp was a brilliant idea. It saved my butt multiple times just on this short initial excursion.

I bought a tube of clear caulk this morning and have a can of Great Stuff expanding foam regular type. Heeding the warnings about the foam straw clogging and the need to do all the foaming in one session I think I may remove the other half of the addition and then try to get near the roof edge and foam the half inch gap.

So far have not been able to get closer than two feet, so I am hoping that my arm might stretch or that the foam sprays out with a little force so I do not have to be in direct contact.

I am considering trying to make a support that will be 14 inches wide and have some four inch hangers that will latch over the floor joists. If I do that I can put it into the joist bay and put some weight on it so I can get a few more inches clearance.

Although I am very careful about the ceiling, it seems that if I am sitting on my plywood crawlers I can put my leg down onto the ceiling as long as I don't lose my balance and put serious weight on the leg.

I am treating this like a haz-mat operation. I suited up and duct taped my wrists and ankles to avoid particles getting in there. I had the respirator, goggles and knitted cap so the only real opening was at my neck. I wish I had a turtle neck shirt or a disposable scarf for that - I will hunt something down for next time.

I decontaminated in the upstairs bathroom, took a cold shower to get particles off and am washing my clothes. That will take about an hour then back to work.

The decontamination practice will come in handy if someone blows off a small nuke in NYC and we get fall out :-)

With regard to the low gable ventilation, would you think that cutting in the vent and then attaching some sort of long duct would be a good idea? I could run the duct along the edge of the attic and cut openings in the top of the duct every few feet to let the air come out - or do you think it might be better just to run a solid duct to the middle of the attic so the air flow is more consistent?

The house was built in 1960 and the addition sometime after that. However aside from grounded outlets the construction techniques seem similar.

I currently leave the attic hatch open about a foot in the summer and open a couple windows on my second floor to try to increase the air flow. I only use a small window A/C in my office so leaking air from the house to attic in summer is not a problem.

Do you think I should make a premanent crawl zone in the addition after I lay the 6 inch batts?

I don't think that the attic has enough space to stand up even at the peak, so making a study will not work. At this point I am full steam on plan A - insulating the attic floor.

As usual thanks for the advice. I really appreciate it.

[samclem]

Quote:

Originally Posted by joesxm There is an opening about half an inch where the two 2x4's come near each other.

Is there any chance that this is some type of intake vent for the attic, or just an artifact of the dimensions of the wood? I'm having a little trouble "seeing" the way the framing is done. It sounds like far too little vent area at any rate.

Quote:

Originally Posted by joesxm So far have not been able to get closer than two feet, so I am hoping that my arm might stretch or that the foam sprays out with a little force so I do not have to be in direct contact.

Sorry, but the straw has to be within about an inch of where you want the foam placed. I've had good luck in taping a drinking straw to the end of the factory-supplied one (use a lot of tape, and bring some extra straws into the attic with you in case one gums up. Again-very sticky stuff, watch your eyes and keep it off your skin. Don't wear clothes that you like).

Quote:

Originally Posted by joesxm With regard to the low gable ventilation, would you think that cutting in the vent and then attaching some sort of long duct would be a good idea? I could run the duct along the edge of the attic and cut openings in the top of the duct every few feet to let the air come out - or do you think it might be better just to run a solid duct to the middle of the attic so the air flow is more consistent?

Your duct idea sounds fine. Running them along the roof edge would give better results than my idea of running it down the middle (esp in the summer, as you'd get nice flow underneath the entire roof deck and out of the ridge vents.). It doesn't need to be much of a duct, you could just put a small "wall" of styrofoam up between the top of your attic-floor insulation and the rof deck, leaving a 1" gap at the top for the air to come out. The bottom of the duct would be formed by your new insulation, the (slanted) side/tp formed by the roof deck, and the "wall" inside formed by the styrofoam. The intake vents on the gable walls will need to be fairly large. When you are done you want the vent area (high vents and low vents combined, each comprising 1/300th of the ceiling area) to equal 1/150th of the total area of your ceiling. That's total "net free vent area", so it will actually have to be bigger to take into account the resistance of any grills/screens. Assuming your ceiling has an area of 1000 sq ft, you'd need 480 square inches of net free vent area down low. Add about 20% for low-loss screening over the vents and you've got a requirement for 576 square inches of vent. You could have four intake vents at the edges of your roof running to ducts along the edge, and maybe add other intake vents in the middle of the gable (with a duct down the center) if you need more intake area.

Quote:

Originally Posted by joesxm Do you think I should make a premanent crawl zone in the addition after I lay the 6 inch batts?

I would. You'll be back up there.

[joesxm3]

The gap was not intentional. On one end there is no gap at all, on the other end close to an inch and a half. I think it was just cockeyed construction.

It may have been some intentional or unintentional air flow at one time, but when the guys put the siding on they nailed a board all around the very top of the wall just under the gutter and wrapped it with metal. This effectively blocked off anything that might have been there.

I managed to finish 7 bays on one half of the new side and to put crazy foam in three. I figured it better to let the foam hardend before pushing the batts.

I ended up squirting a ball of foam about the size of a grape where I could reach and pushing it with a stick to move it to the gap. I probably should have had the large gap foam. I was really careful about getting foam on my, but came down with some on my hat and I had a hole in one finger of my glove. The tip of my middle finger is now stained black with two small dots of foam stuck to it :-)

I found a good use for the old insulation. At the very edge of the roof edge it will be impossible to put the 9 inch R30 rolls. What I am doing is taking pieces of the old insulation minus the vapor barrier and pushing it with a long stick to fill up that area. I plan to fill up with that until the under rafter space is 9 inches tall above the joists so I can easily roll the R30.

??= it is ok to put the old insulation directly in contact with the roof plywood around the edges right? Since there are not soffit vents I do not have to worry about blocking ventilation.

I am suiting up for another session and will be up there in a few minutes. My goal is to remove the other half of the new area, caulk and lay the batts. My stepfather is coming for another dump run tomorrow and I hope to get 12 rolls of R30 in the truck. My calculations indicate I need around 30 rolls for the whole attic.

BTW - You told the story of running out of staples earlier. I had a similar incident. After loading the caulking gun and crawling like a flattened moust to the edge of the roof side where I could just barely reach with the caulk gun I found out that in addition to cutting the spout you need to pierce the foil inside - back down to the cellar to find a nail :-)

One hopeful note - it may be an optical illusion, but it seems like the rafter angle is steeper on the back side of the house. It that is true there will be more clearance for me to crawl under to reach the roof edge.

Another thing, with the 9 inch roll insulation on the floor the gable vents are that much closer to the floor and might be better intake vents because of that.

[travelover]

Quote:

Originally Posted by joesxm ............. I probably should have had the large gap foam........... .

The foam hardens and expands due to reacting with moisture in the air. You can make it really expand by squirting the surface of interest with a water spray first. Preheating the can helps, too if it is less than 70 degrees or so. Submerge in warm water - no microwave......

[samclem]

Congrats on the progress to this point, it sounds like things are going well. The Great Stuff will expand quite a bit, and it can do so with enough pressure to bend wood. The solution is to either use "just enough" or buy the "Windows and Doors Great Stuff" which expands less and expands with less pressure. You'll be fine with the regular stuff if you just take it easy and don't try t fill the gap for the whoe depth of the wood--you're just trying to stop the airflow, not add insulation, after all.

Stay safe up there!

[joesxm3]

I might have put too much Great Stuff, but it seems to just have expanded out rather than bending any wood. The foam is really hard to control at long distances, but I seem to be getting the hang of it - you need to plan for the extra amount coming out after you stop so let up ahead of time.

I managed to seal most all of the cracks in the new side and used one whole tube of caulk and two cans of foam.

It is much more time consuming and difficult than I expected but things are at least working out well. Given the tight space I have to plan every motion like an astronaut would on a space walk - that takes time. I am also very sore from using may previously undiscovered muscle groups.

The headlamp saved my butt yet again. Last night I knocked over the worklight and the halogen bulb crapped out. I was able to find my way back out of the attic with the headlamp.

One thing no one mentioned was knee pads. I bought a robo-cop pair from HD and they are paying off in spades.

I took a couple of side trips. I noticed that my back porch was desperately in need of staining and since it was 60 degrees for two days in a row I ended up doing the entire outside 12 feet by 30 feet by 8 feet and then the next day I did the part of the floor closest to the elements six boards deep and 2 feet along each side. It was not my best painting, but I went very fast and got the job done relatively quickly. My new respirator was nice since the stain I use is pretty toxic. I wore it for the initial sanding and for the painting. I could not even smell the stain at all while wearing the respirator.

I also picked up all the leaves yet again on my 1 acre lot, went to the dump, brought back 24 rolls of R30 insulation from HD and sawed up about 150 small logs for my wood stove.

At this point I have managed to do all the prep work on the new side and install 16 out of 20 batts on the roof sides of the attic. Four bays have special details such as extra 2x4 nailed in to attach sheet rock to or very many wires so I saved them for later.

In the middle of the room I will need to put in at least 10 more batts to finish things off, but I left them open until I get near the gable wall to put the insulation into the little 2 inch wide bays near the wall.

I am very happy with the quality of the Owens Corning batts. The are nice an fluffy and fill the joist bays perfectly.

I can now see the point about how much easier it would be to just blow in the insulation and be done with it in one day. However, I think that the sealing of the cracks in preparation would have taken three or four days - unless I skipped it and just blew over the old insulation. Given the double vapor barrier I would probably have had to at least lift the top layer and remove the paper - so a lot of demolition work in either case.

On another note - the new stove arrived today. It is very nice looking and matches the new white hood that we installed a few weeks ago. I still have to strip wall paper and repaint, but that will not be until next spring.

Thanks again for all the advice on this project. Although it will be weeks before I finish I will be proud to have done it and will rest easy with my R49 insulation in the attic.

[travelover]

Joesxm, slow down, man. You are making me tired just reading this....

[samclem]

Dang! Sounds like things are going rapidly and well. I did forget to warn you about the need for knee pads. Another thing that started to hurt was the palms of my hands (from the concentrated loads on the heals of my hands while crawling over the joists). I suppose gloves with padding in the palms would have helped. It got pretty bad after a few days, and I started to wonder if i wasn't causing some nerve damage in there. The pain went away about a week after finished, but if I had it to do again I'd look to buy (or make) something to prevent this problem.

Other small points:
- I bought some florescent marking tape and hung a streamer down from the roof deck directly over the point where there was a junction box, ceiling fan box, light fixture, etc under the insulation. I labeled the tape with the identity of the item. It's a small thing, but has already saved me time when I needed to locate something under the insulation--the hanging tapes are easy to see from a long way off. I just used a staple gun to tack them up.
- I took pictures of the insulation "before" and "after". I also photographed a few places where I'd done the caulking, etc. Someday I might want to sell this house, and this will go in the sales book.
- At the entrance to the attic I put a small data card with the date and showing the brand and thickness of insulation I'd installed.
- Light fixtures: Obviously, no insulation should be in direct contact with can lights or other fixtures unless they are rated "IC" (for "Insulation Contact"). You have to ether replace them with IC fixtures or build a box around them to (drywall is best) to keep the insulation away (I think the distance is 3," but be sure to check).

Congrats, and keep us informed on the progress.

[joesxm3]

I think I do not have any "can lights". All the light fixtures hang down inside the room and all I see from the attic is a metal junction box or a wire going down into the sheet rock, so I think I am ok on that.

Nice idea about the pictures. I have been taking quite a few. Once I got the first roll of R30 spread out it looked so dramatic towering over the in joist R19 that I took a picture to enhance the contrast.

I have been plugging along and today managed to finish off the new section 10 joists by 22 feet. The old section has 24 joists by 22 feet, but part is walled off for the bathroom cathedral ceiling.

I have been able to re-use about half of the old insulation. I use it to fill in on the edges and have rolled up some and pushed it into the roof-edge parts that are less than 9 inches tall so I can just roll the R30 next to it once I have the 9 inches of clearance under the rafters.

Rolling the R30 is certainly much easier than removing the old and squeezing to caulk and push the batts. I have used up three tubes of caulk and three Great Stuff cans so far, so it would seem I have a lot to fill in.

My hard drive has been giving problems, so I have not been online as much as usual. If I drop off the face of the earth it probably means that my hard drive died and I am working to move to my new Dell.

If I had realized what I was getting into I might have thought twice or maybe just rolled the R30 over the old stuff. However, I am happy to be doing things right. The more I think about the blown in celulose, the more I think I would not be happy with that much loose stuff all piled up in the attic, so I probably made the right choice for me with the pink fiberglass - but I do feel bad about not being as green as I like to think I am.

As usual, thanks for all the help.

[samclem]

I saw a product advertised in this month's issue of Fine Homebuilding that would be useful to those with a situation like yours. It provides intake ventilation for homes without soffits. Basically, when the home is re-roofed, a slit is cut into the decking about 18" from the lower edge of the roof and this vent is installed along the entire length of the roof edge, then shingles are put over it. It allows for an unobtrusive approx 3/4" gap between the shingles that allows air to enter, just as a ridge vent allows the air to escape). Sorry, I'm away from home ad don't have the magazine handy, but it looked interesting and might be a good approach for somebody who had no soffits AND was re-roofing their house.

[joesxm3]

Sam - that product seems like a perfect thing for me but unfortunately I have already had the re-roofing and have some sort of underlying water shield that goes four feet up the roof to protect from ice dam water seepage so cutting it is probably not a good idea.

Good news on the project front. The old part of the house is two feet wider and one foot taller than the new part. This makes working in it easier by a surprising amount. The workmanship on the old side is much better so I have had very little caulking to do.

So far I have managed to finish more than half of the old side so I can see the light at the end of the tunnel. I have also made arrangements to give some of the left over old insulation to a guy at work who needs to insulate the ceiling of his three-season room and is looking to save money so he will make due with the less than perfect old insulation.

Tomorrow is the last dump day of the year so I am taking a load of scrap and trash and hopefully buying the last two or three bundles of R19 batts.

I think that I may be having the problem with the hands that you mentioned. My right arm has been hurting and the fingers have been going numb, not to mention lower back ache from all the crawling around. I am going to suspend work for a week or so to give the old body time to recover.

Being out of shape and 52 is not the best recipe for manual labor. But as was said - "whatever does not kill you makes you stronger".

I think I will enjoy the winter rest once this is finished.

[ls99]

Great work. I went thrugh similar excercises on two previous and current house. IMHO sealing cracks with caulk and foam, is the biggest PITA, but in the long run pays the most benefit. Since insulation in and of itself does not stop airflow.
Reduction in air changes per hour pays off big time by not re-heating infiltration air.

Cheers. Then snuggle up in a nice warm house and enjoy.

By the way: I also foil taped all holes, and sealed with foam around all of the attic/ceiling mounted electrical boxes. You would be surprised at the amount of airflow through and around them. Also sealed cable, pipe feed through hole in sill plates of attic and basement.

[joesxm3]

I have been lucky that most of the electrical boxes were already sealed, but I do have a lot of non-standard pipes and wires above the bathroom that was remodeled by the previous owner. I am saving that for last since it is a lot of sealing and custom batt cutting.

I have yet to mention the two sky lights in the bathroom. I suppose we will need to discuss those at some point. I suspect that they are big heat loss areas. I had considered putting some sort of plastic or foam panel insulation on them for the winter, but I am worried that I will trap moisture.

That will probably be a project for next year along with painting the ceiling with the laquer mentioned by samclem.

[ls99]

Re: skylights. If you like the looks, some pain (heat loss) maybe worth having. That said, you might try a piece of polycarbonate cover on the outside, (top of glass), sealed at the edges. Would give another R2 or so, if glass is double pane -total of R4. Hey, that's a 100% improvement.

[joesxm3]

Not a bad idea, putting something on the outside.

Sounds like a job for me and Mr. Duct Tape - At least a half-assed attempt for this season and then something better next time.

The back ache continues, so I think I must have pulled a muscle by leaning over and lifting the plywood crawl-on pieces. Once I recover I have to clean the gutters, so while I have the ladder out I will attack the outside of the sky lights.