hello from central IL

[scottorious]

hello everyone. I am new obviously. I think so far this forum is pretty cool. I love looking at DIY stuff, a lot of times the commercially made products just arent cost effective at this point and part of ecomodding a house/car is about saving money! If anyone around central IL is in need of some labor on a project I would love to get some hands on experience as I just bought a house and need to start getting some ideas on some potential projects.

[Daox]

Welcome to the site. What kind of stuff are you looking into doing with the house?

[scottorious]

well to begin with the house was built in 1936 so I think it would be safe to say that its insulation is sub-par. I plan on rennovating the entire second story which isnt much because its a fairly small house. The problem I am running into with insulating the second story is that its actually a 1.5 story house. So the walls are actually the ceiling also. Not a lot of room for insulation. I am looking into the mooney wall technique as a way to break the thermal bridge and to increase the width of the wall/ceiling for some increased insulation. In the rennovation of the second floor I will be removing an old chimney which vents only the water heater. in place of the current water heater I am looking to get a direct vent tankless. what better to feed a tankless water heater than a solar heating system. The house is small enough and I have enough room in my basement to put a large storage tank. so once that is complete I hope to take that heat and use it for space heat as well. at some point I would like to do a graywater to toilet system, but thats the future.

[AC_Hacker]

Originally Posted by scottorious

what better to feed a tankless water heater than a solar heating system.

Sounds like a good idea...

Just make sure that your demand water-heater is designed to work with some kind of pre-heated water.

Many of the demand water heaters do not sense the temperature of the water, but rather sense the pressure, and adjust the flame accordingly.

Others (the kind you want) actually sense the temp of the water coming out and adjust accordingly.

-AC_Hacker

[scottorious]

good idea. I havent been looking at them much yet. I guess I thought all of them did that. good thing I got that bit of info. Any ideas on good brands/models?

[AC_Hacker]

Originally Posted by scottorious

good idea. I havent been looking at them much yet. I guess I thought all of them did that. good thing I got that bit of info. Any ideas on good brands/models?

I have a Bosch. My model is not the temp sensing, wish it was...

But it's been cranking right along for many years.

I hear good things about Rinnai.

They both make a temp sensing model.

There's a lot of really inexpensive ones on ebay. Getting parts could be an issue.

-AC_Hacker

[ThomSjay]

Hi!
I have a 1.5 story house as well. When I recently renovated one upstairs room, I put 1/2" thick by 1" wide spacers against the roof rafters for an air gap, and then filled the space with layers of 1 1/2" isoboard. That gave me R27 in the rafters. On the small ceiling portion I have about R52 of rock wool insulation. The knee walls in that room have R20 but the end wall ended up being only R14 (before I came to this site).

[scottorious]

that is also an interesting idea. I have thought about using the foam board up there. thats a very diy kind of project. what are the cons of layering foam board in the rafters? I have even thought about using great stuff to seal it off and have the same benefits of the spray foam without the expense.

[AC_Hacker]

Originally Posted by scottorious

...I have thought about using the foam board up there. thats a very diy kind of project. what are the cons of layering foam board in the rafters?...

scottorious,

This is an approach that I have a good bit of experience with.

I decided to go this route because I wanted to get the most R-value in the least space. I have the same house configuration that you have.

When you work on your walls/ceiling, you will want to be mindful of two things:

• Infiltration
• Insulation

My first efforts were to use fiberglass and put it in the wall and then sheet rock over it. That method was better than no insulation at all, but it didn't get at infiltration, and because of this, the insulation in the wall was not as effective as it could have been. Also, the insulation I put in at the time was rated to be R-13, not so high, and the flow of air through the wall degraded that R-value considerably.

My second effort was to fill the wall cavity recycled shipping peanuts, because it was free, and testing showed it to be on par with fiberglass. Subsequent testing on a plastic peanut/pearlite mix proved much better, because the pearlite filled in voids in the peanuts, and yielded an R-value that was higher than cellulose. I used this combined method on one side of the house and it worked well, but not as well as subsequent methods...

My third effort was to use recycled insulation board chunks in the wall, but I didn't seal between layers or pieces, so the efforts were little better than nothing.

My forth effort was to use new rigid foam board (expnaded ploy-styrene, AKA: EPS), carefully cut exactly to size and layered in the wall until the cavity was filled 100%. This worked so well that I was shocked at the difference between this method and all previous methods. The difference was that I had completely eliminated all air movement in the wall (infiltration), along with using an R-4 to 4.5 insulation. Using this method, I was actually getting minimum R16 in the walls, instead of using fiberglass reated at R-13 in an unsealed cavity and having that R-value degraded to some unknown value that was significantly less than R-13, by air flow through the wall.

I was so impressed with this method that I thickened the walls and roof an extra two inches to recieve another 2" layer of EPS, in the walls and ceiling.

I am continuing to work with this method, with the exception that instead of cutting exactly to fit, I now cut 1/4" all around and run a bead of canned foam in the 1/4" gap to seal it. This has proven to be easier than cutting exactly to shape, and makes a better seal at the edges. Care must be taken to not allow the canned foam to get behind the EPS, because it will expand and push the EPS out.

When I was selecting foam board to use, I had the following choices:
Expanded Polystrene (EPS) - (R-4 to 4.5 per inch)
Extruded Polystyrene Board (XPS) - (R- 5 per inch)
Polyisocyanurate Board - (R-6.5 per inch)

In making my selection, I tried to weigh cost vs. R-value and decided on EPS. Subsequently, I have read about the possibility of degraded R-value in Polyisocyanurate, due to the gradual absorption of moisture. Here is a link on that issue, you should do further research.

Also the cost of energy has gone up since I started the project, I might lean more towards XPS now, especially important in the ceiling.

Another issue for you to consider is that using this insulation method will radically reduce the infiltration of air into your house, and you will require mechanical ventilation in the winter, I would recommend some kind of heat exchange ventilator (AKA: HRV). The mechanical ventilation will be required both for humidity control and also for air quality.

Also, for this method to be completely effective, you need to concentrate on the junction where the roof-slope meets the wall, and make sure that this area is totally sealed. Same goes at the details around the foundatoin and the junction where floors meet walls.

This method is not easy or cheap, but given that you are working on an older house, it is amazingly effective.

Regards,

-AC_Hacker

[Daox]

There really isn't a drawback. Its just a fair amount of work, but as you can see the R-values are really nice.