Insulation question

[Bob M.]

I have a house built in 1956 and it seems like it needs more insulation. I think the attic is okay (there's about 18" of cellulose there) but my concern is the walls. The house seems unbelievably hot in the summer, and this is with the new low-e windows installed. Gable vents were added last year, they made some difference, but I would expect the house to be cooler than it is in the summer. (At midnight outside temp = 70, inside = 85)

There is no a/c here nor will there be (baseboard heat). Probably don't need it either.

Since the place is already built, how can I tell how much insulation is in the walls without ripping them out? I would imagine my only answer is blown-in insulation. Does it make a difference? I'm thinking it would. Enough to justify the cost of about $1,000?

I do get direct sun 365 days a year on the south (front) side. Front lawn is too small to plant trees to block the sun. Oh yeah, the roof has two layers of shingles on it, the previous owners being too cheap to re-roof it properly. I suspect that adds to my problem.

[Joseph Meehan]

You have several options. First thing that needs to be done is to check to see what is in the walls. It would also be good to have a survey done (maybe using thermo imaging equipment) to determine where the problems really are. This may save you money in the long run and result in better results.

I will suggest that you will also need to add some ventilation to the house to bring in cooler air. An attic fan (not the same as attic ventilation) might be in order.

For real comfort, you are going to need A/C. Baseboard heat does not mean no to A/C there are a number of possible alternatives. I might suggest that you may actually save money by updating the whole system to a new modern higher efficiency heat and cooling system. Get an estimate for that. Electric baseboard heat is comfortable, but it is also very expensive.

[Speedy Jim]

It would be unusual for a 1956 house to have any wall insulation in *most* parts of the country.

Find out if it has any insulation first off. Often, you can tell by exploring around a recept/switch box on an outside wall. Or, find a closet on an outside wall and make a discreet opening.

If there is none, you'll be able to make a "huge" difference with blown in.

Jim

[Tony Hwang]

Hmmm, Where do you live?

[Edwin Pawlowski]

If you live in a cold climate, payback will be F A S T. Aside from the money, thee is the comfort factor.In the summer, you also need more ventilation in the house. You state at midnight the outdoor temperature is

70, but what is it during the day? The house also acts like a big heatsink, especially if there is a lot of masonry. All day the summer sun is heating it and they it radiates that heat during the dark hours. Even a window fan will help move the cooker air in.

Check around receptacle or switch boxes to see if there is a gap at the plaster so you can get a peek. Next alternative is to open up a small hole.

[Bob M.]

Montana.

House has aluminum siding on it (I believe there isn't any styrofoam under it), two layers of shingles, vents running the length of the underside of the low edges of the roof (someone putting in a bathroom fan last year said he could see daylight, so they're apparently not blocked). In the summertime, none of the windows get direct sun, except for two in the very early morning and another two very late in the day. (In the winter, all the south-facing (front) windows get direct sun all day) Window replacement project will be 100% complete in two weeks, only two left to do. (The original 50-year-old, single pane, non-low-e windows just didn't cut it anymore! You should see the faded paint in one of the rooms.)

Daytime temps got to 90 degrees last week, at midnight the outside temp was

70 but 80-85 inside. Windows open, windows closed, fans on/off; nothing made much difference.

I suspect I have _at most_ 1" of insulation in the walls. Just a guess tho'. For noise reduction alone I should do blown-in; my bedroom is 15' from a fairly busy road.

Are thermal cameras easy to find? The local gas & electric co. is coming out here in the next month or two to do an energy audit but all their info does not say a thing about taking a thermal picture of the house. (this audit apparently takes 2-3 hours and does involve some sort of pressure test of the home)

I'd rather not bother with air conditioning, partly due to the noise (no other house in the area has it) and I really think if I fix the basic problem, then a/c will be largely unnecessary, except for maybe a month each year.

Yes, the gas-fired hot-water boiler is 50 years old too, and it should be replaced but after spending nearly $8k on windows over the past 10 months, I'm not in much hurry to replace something that's not broken, at least not this year.

[Stubby]

But be careful with blown-in cellulose. We just had a lot of flooding here in the Merrimack valley(MA). I heard many home soaked up flood water and expect to have mold even after it dries. And that ignores the fact that raw sewage was pouring into the river.

[Pop]

Your main complaint seems to be that it stays hot at night after it cools down outdoors. That indicates a lack of air flow. REmember, insulation works both ways; it'll keep heat IN also (e.g. cold OUT).

Sounds like minimum, some controlled ventilation is in order. Or open the windows on breezy evenings?

Pop

[Mac Cool]

Bob M.:

We have the same problem in our brick house, built in '59, no insulation in the walls... brick soaks up the heat all day and radiates at night. We can open every window in the house and put fans in the windows and it only helps a little.

[George E. Cawthon]

Those temperature differences are way different from what we experience. Our house has the standard crappy insulation in the walls, but good insulation in the ceiling. Even if you had no insulation in the ceiling and walls, your house temperatures should not be 80-85 inside when the outside temp is 70. I'll bet you have a lot of trapped very hot air in the attic. The first step for comfort is to get air flowing through the attic, then get plenty of insulation in the ceiling (attic). Wall insulation is important, especially for retaining heat, but isn't going to make much difference in cooling compared to the improving attic air flow and attic insulation.

We lived in a gov't house once that had little insulation. I looked in the attic once and it had

3-1/2" batts but they were laid over wires had space where you could see the ceiling. Our house temperatures cooled rapidly with the outside temperature. That's another reason I think you have trapped hot air. You need flow in at the bottom and flow out near the peak of the attic.

[trader4]

As J. Meehan suggested, since you dont want ac, this is a good case for a whole house fan. The fan goes in the ceiling of an upper floor and moves air from the house into the attic and out. It won't help when it's hot outside, but it will cool the house very quickly under the above conditions.

You need enough attic vents for the air to go out. If all you have is gable vents, I would go with a ridge vent, whether you use a whole house fan or not. A ridge vent is a lot more effective than the gable vents in moving hot air out.