Re-Insulating the Kitchen...

[AC_Hacker]

I live in a small, 120 year old house. When I moved in there was no insulation at all. I started with R13 fiber glass in the cavities, with no knowledge of, or regard for movement of air in the wall cavity. As the project slowly progressed, my methods have also progressed. I have come to realize how serious the energy issue is and how important it is to insulate really well. So I am now at a point where I am removing insulation I previously used and updating it, using better materials and techniques.

I have settled on using EPS rigid foam board in the wall cavities, and increasing the wall cavity by 50% (to an actual 6 inches), and filling the cavity with EPS (three layers of 2" board), that is carefully cut, layered and sealed.

In the kitchen, three of the walls are exposed, and I have already insulated the ceiling, and two walls, leaving the third wall and underneath the floor to do now.

First job was to remove the sheet rock. Here is the 4" wall with the R15 fiber glass waiting to be replaced.

Here is the wall with the R15 removed. I put duplex outlets along the top of the walls, as well as the bottom for greater flexibility in lighting. The top outlet of the outlet is switched by the kitchen light switch, the lower outlet is always on... Note the caulking that I did from inside the wall... I was trying...

Because I will be making the wall 2" thicker, the electric outlets will need to be brought forward by that amount... In some cases, there is enough extra wire in the wall to allow for the outlet move, in other cases, I will need to re-wire.

Here the firring is going on. One of the last things I learned about is the importance of reducing thermal bridging, do I am using skip-spacers and filling the spaces between spacers with 1/2" foam strips. Not the very best way to prevent thermal bridging, but better than nothing.

-AC_Hacker

[Geo NR Gee]

Hey nice wood floors. Seems like thats a bonus when you purchase an older home.

Now if only I was that brave to take the sheetrock down, pull the old fiberglass down and do what you are doing...... What do you expect for R value once you have it complete?

I bet the other benefit of the rigid is the ablity to block drafts.

Great job AC

[S-F]

Nice!

How are you going to be sealing the EPS? Hopefully if you get a really good seal between each sheet of EPS and all the surrounding lumber the leakiness that board sheathing should be reduced to a minimum.

Go Go Go!

[Daox]

Very nice. An upgrade from a semi-leaky R15 that likely gets worse as it gets colder out to a nice solid R30 is quite the improvement!

[hamsterpower]

Good job. I am almost finished with a similar job on my kitchen. With all the different step for air sealing you are doing, why are you not just using a large spray foam kit? That is what I did.

[AC_Hacker]

Originally Posted by hamsterpower

Good job. I am almost finished with a similar job on my kitchen. With all the different step for air sealing you are doing, why are you not just using a large spray foam kit? That is what I did.

What was the cost per square foot?

I'm doing this on a pretty tight budget.

There is also another factor involved here, in that my son who is helping me at $10/hr, is not able to find other work, so this is sort of a mini WPA project, to help him through the tough times.

But all-in-all, if the cost is cheaper I could hire him to do this and also other projects... There is still the space under the floors to do... That's really gonna eat up a lot of foam.

-AC_Hacker

[hamsterpower]

Originally Posted by AC_Hacker

What was the cost per square foot?

I'm doing this on a pretty tight budget.

-AC_Hacker

600sf kit w/ shipping was $698. I sprayed ~3 inches over ~200sf. so 700/200 = $3.50 /sf. I also increased the thickness of the wall to 8 inches. I filled the rest of the cavities with blown in cellulose. I only needed a few bags after what I salvaged during demo. Anyway, I'd guess it was quicker and about the same cost/sf as your project.

[AC_Hacker]

Originally Posted by Geo NR Gee

What do you expect for R value once you have it complete?

That is the great question.

The older stufff I was buying was rated at 4 to 4.5/in., and this newer stuff I'm buying is rated at 7.8/2" or R-3.9/in. I don't know if they are using different process/materials, or if they were forced to get honest.

So, I'm expecting R-23.4 from the foam in the walls. There will be an extra R-1 for the wood, R0.5 from the sheet rock and maybe an R-1 for the air barriers at the surfaces of the wall, for a total of R-25.9 or so.

Then there is the thermal bridging thing, and with regular studs, I'll lose 18% for and honest R-21.2. My efforts at thermal bridging reduction should up that at least a bit.

It was suggested to me that a 1/2" foam layer on the inside, over the studs will go a long way to reduce thermal bridging. My grand plan is to do an outside wrap too... but that may be in the distant future. I have been purchasing duplex outlets that have screw-adjusters and that gives me the option to add the extra 1/2" foam wrap inside, if I want.

Originally Posted by S-F

Nice!
How are you going to be sealing the EPS?

Great Stuff at all edges... After the foam sets up, I trim it back flush, then I stagger the joints when I do the next layer, and foam and trim, etc.

Originally Posted by S-F

Hopefully if you get a really good seal between each sheet of EPS and all the surrounding lumber the leakiness that board sheathing should be reduced to a minimum.

That is what I am counting on... zero infiltration through the wall.

Doors and windows are a different matter.

Originally Posted by Daox

Very nice. An upgrade from a semi-leaky R15 that likely gets worse as it gets colder out to a nice solid R30 is quite the improvement!

I'm afraid R-30 might be a bit optimistic, but an honest R-21.2 will really help a lot, especially considering that I live in an area with 4,500 annual Heating Degree Days.

So far, even with just 2 walls and the ceiling done this way, the infiltration reduction is quite noticeable, and already, I completely recognize the requirement of a HRV in the project.

Originally Posted by hamsterpower

600sf kit w/ shipping was $698. I sprayed ~3 inches over ~200sf. so 700/200 = $3.50 /sf. I also increased the thickness of the wall to 8 inches. I filled the rest of the cavities with blown in cellulose. I only needed a few bags after what I salvaged during demo. Anyway, I'd guess it was quicker and about the same cost/sf as your project.

Wow! I'm totally impressed with your method. The economics works out pretty good, too.

This project is already underway, and pretty small, but I may use your method as I progress into other rooms.

Thanks for this info.


Thanks all, for the encouragement...

-AC_Hacker

[Daox]

What're you using thats only R3.9 per inch? The extruded polystyrene I see in the store is all rated at R5 per inch (owens corning).

[AC_Hacker]

Originally Posted by Daox

What're you using thats only R3.9 per inch? The extruded polystyrene I see in the store is all rated at R5 per inch (owens corning).

I will search it out.. Thanks.

-AC_Hacker