Building a house, want a gasser, advice needed

[heaterman]

With 13 grandkids living within 3 miles of my home there is no shortage of extra curricular activities in which to participate.

You are correct in saying there are different strokes. If I had little else to do, cutting wood is a good wholesome past time and one I enjoyed when I did it.

I'm burning wood again but in a different form. I have a pellet boiler running my house that takes a grand total of about 3-5 minutes per week of my time.

 

[ihookem]

Four years ago I spent 7k on the best insulation job a guy could get on the same size house OP is building. I don't think it will cost him 15k. Not even close. I did have to pay cause I don't have a foam truck. Fiberglass insulation a guy can do himself but I wouldn't use batts unless they were free. For a bit more than batts in the wall a guy can blow in cellulose for a way better job. I did this on my first house and was good. I built the same house on the same foundation and can tell ya that foam is much better than blown in cellulose in the walls, and cellulose is much better than batt ins.

 

[pwschiller]

Four years ago I spent 7k on the best insulation job a guy could get on the same size house OP is building. I don't think it will cost him 15k. Not even close. I did have to pay cause I don't have a foam truck. Fiberglass insulation a guy can do himself but I wouldn't use batts unless they were free. For a bit more than batts in the wall a guy can blow in cellulose for a way better job. I did this on my first house and was good. I built the same house on the same foundation and can tell ya that foam is much better than blown in cellulose in the walls, and cellulose is much better than batt ins.

Below is what Noah described, again:

Hey Bret,
Here is where I coming from- Currently I am building a new house for my folks. 2200 sq ft, R15 below grade, R30+ above grade, R60 attic, R5 triple pane windows(high SHGC on south facing glass),
aiming for around 1 ACH/50pa, 5300 HDD climate. Annual calculated heat load of <20 million btus...

ihookem, you don't seem to go into much detail other than to say "... the best insulation job a guy could get..." Just so we are comparing apples to apples, is your house around 2200 sf of heated space?

How did you insulate your walls to an effective R30+? Are you saying that you had 2x6 walls spray foamed for that? You would either have to do that, stick frame with 2x10's and use batt insulation, use R32 SIPS, use ICFs (like Arxx), or build standard 2x6 walls with batts and then wrap them with another 3" of XPS foam sheathing. There may be other approaches, but none of them are cheap. And, you also have R60 in your attic, R15 foam below grade and R5 triple pane windows? You're saying that all of those upgrades over standard "to code" construction only cost you $7000.

I know that for my 1600 sf workshop, all of those upgrades would have cost me around $15K. That would have precluded me from using the twelve 3'0" x 5'6" double pane Pella windows that I got on closeout from Lowes, including screens, for only $143 each. The used full light Thermatru doors I got through Craigs List wouldn't meet that standard. The extra XPS sheathing to take my basement walls from R7.5 to R15 isn't cheap. I hate working with fiberglass and I dislike that it can be a great medium for growing mold, but I was on a fiberglass kind of budget. The walls have R19 with kraft paper and the attic has anywhere from R38 to R49 in it; all of that fiberglass cost me under $1100. Adding extra insulation to the attic is fairly cheap and easy. Upgrading walls to R30+ is not.

Also, is using cellulose in walls recommended for new construction? It's a great product for attics, but I have heard concerns about it settling in wall cavities, so you end up with no insulation at the tops of your walls.

Edit: There are some people who build a timberframe and then insulate it with straw bales covered with earthen plaster. You could build R30+ walls that way. It can be a great healthy, green building option, but requires lots of work on the part of the homeowner/builder and probably their friends. You don't see it much in the northeast because of all the precipitation we get; it's a better option in a dry climate.

Pete

 

[mark123]

When I built my house 6 years ago I wanted to make the whole wood things as easy as possible. I built it with a walk out basement with a garage door to the boiler /wood room and that room is as air tight as possible to eliminate the smoke, dirt etc.. from entering the house. I used exterior door with weather stripping from the boiler room to family room. I installed a woodgun E-180 with built in oil back-up and so far am happy with it. I heat 4000sf and all domestic water all year round with 8 cord of maple and 2-3 cord softwood for the off season.

Although a newbie,

I've done a little bit of reading and made a few unofficial decisions. I plan to build a 2200 square foot cape or squished cape with attached 2 car in Central Maine in the summer of 2014. I'm leaning towards Tarm Innova, but not set on it. I'm open to all referrals. I've decided to go with stacked 500 gallon propane tanks, I will build and stratofy them myself. For an expansion tank, I was thinking to use a separate 250 gallon tank with a water/nitrogen interface for expansion. Fill both 500 gallon tanks, and fill the 250 about 20%, use only one port for water entrance(the bottom of the tank). Draw a vacuum and add nitrogen to the top of the 250 for compression gas. I'm worried about getting suspended nitrogen in the system somehow. What do you guys think? Will this work?

Piggy backed with wall mount propane condensing boiler. Probably boiler-mate for DHW.

This is going to be the house I want to live in forever, so I don't want to skimp hard on things, especially those that my save me money in the long run.

Is this true that you get more use from your tanks with radiant flooring? I will occupy the house probably all but 2 weeks during the winter. Radiant in the basement, first floor, 2nd floor? Baseboard in the 2nd floor?? Should I heat the garage? This is probably going to be used for actual cars, so I don't really want to heat the hell out of it during the winter, but it might be nice from time to time. A larger offsite garage is in future plans and hope to tap into same system.

Thanks,
Woody

 

[ihookem]

PWSHILLER, yes my house is 2200 sq.ft/ 9ft walls. I insulated with 4" min. closed cell 1/2" osb and tyvek, with brick exterior. Remember, there is 1"-1 1/2" dead are space between the foam and drywall. The air can't excape. This adds R value. The 4" foam is 28 + R3 air space+ R 2 brick I don't count osb or drywall but that does count as another R 2. I believe I am @ R33. The windows are double pain with storms. I don't know what this makes it but it is very good. I have R10 foam(2") outside against the block wall and studs with R11 inside. This should be R22. The basement is very draft free and nice even @ 60-61 degrees ( note: good insulation will make 60 degrees feel several dgrees warmer) The basement joists are 3" foam. The 8" energy heel trusses are foamed 3" min. above walls and foamed 4' up the bottom of sheathing under shingles. I put in 22" minimum cellulose in the attic, foamed and taped around all the can lights. This cost me 7k four years ago. I don't think I could do much more.The basement insulation I did myself so it was not in the 7 k price.I put the garage on the north side of the house to shelter our horrendous wind. This makes a lot of my northern outside walls against the garage. I might even insulate the garage too. Most my windows are south or west facing for sunshine. Also, yes cellulose is a good idea. I had it in my first house walls ( on the same lot) It is called dense pack . What is done is thick plastic is staples on inside of studs. Then a roof stapler is used to staple the plastic with string inside the plastic for strength about 1/2" -1" away from where the drywall is screwed on to. At this point the plastic is very tight. Then cut a hole about 6' up about 3" wide. The blower will blow it in like crazy. As it's blowing you hit the plastic between studs. This packs it in very well. There is no way for it to settle when this dense. I tore the house down when it was 4 years old due to a fire. I opened up several garage walls that were saved. The cellulose was packed solid after 4 years. I bagged them and put them in the new houses attic. Hope this helps. Again, the new house is much easier on the heat load and the only difference is the foam and an extra 6" in the attic. Everything else is the same. My old house calc was 64k @-10 and that seemed high . My new house was not rated for foam cause I changed my mind while building so I don't know the difference. I figure I am at 25k btu @ -10F. or 11 btu's per Sq. ft. @ -10F. Not bad.

 

[Floydian]

Heaterman, Pete and Ihookem- I think you all make some good points here.

Some things that stand out to me-

Unfortunately a 2x6 wall with 2 lb CC SPF is not going perform as an R33 wall. The thermal bridging of a 20% framing factor is going to bring the whole wall R value down significantly. And a 25% framing factor is more likely. The biggest advantage of foaming between studs is the air sealing and that is some expensive air sealing. Here is a much better explanation than I can give:
http://www.greenbuildingadvisor.com...o-help/26996/maximum-insulation-thinnest-wall (post #5 in particular)
Now, a few inches of continuous insulation outside of the sheathing, with lower cost cavity insulation (cellulose is ideal for its cost and moisture buffering capacity) can give a much better bang for the buck and achieve a whole wall R value of 30+ depending on the material selected. On my folks house I have used reclaimed commercial roofing insulation(polyiso) from insulationdepot.com. This material cost us .65 $/ft for 2.5"(R15) delivered.

Now lets look at some numbers. Ihookem figures 25k btus at a design temp of -10. Using the degree day method for estimating annual heating energy shows he would need about 33MM btus/yr+ DHW(I'll guess 10MM btus for DHW) so 43MM btus/yr and he is burning 3.5 to 4 cords a year. I've got to think his EKO 25 is getting more than 11 to 12MM btus out of a cord of wood, even without storage, but it all depends. I'd guess his heat load is more like 40k btus at design temp and this would mean he would need about 50MM btus/yr+10MM btus for DHW. Seems more realistic given the 3.5 to 4 cords he is burning. Not bad numbers at all though he mentions in his sig that the $9400 he has into his EKO install is "still too much$" and I tend to agree. For my folks house I am putting that kind of "extra" money into the enclosure to get the heat load as low as reasonably possible so they can heat the house with a wood stove and a cord or so of mixed hardwood.

Every situation is different. And I understand heating multiple buildings gets tricky, and gassers+storage and low temp emitters are a great but expensive way to do the job. Another option is to build super insulated, reasonably air tight houses with quality windows that don't need the kind of heat distribution systems to achieve comfort that "to code" houses need. And the bonus is minimal effort/expense to be comfy.

With new construction, you basically get to pick how much energy you want to use for many years to come, as well as future generations. That is why I recommended an energy consultant to the OP.
Eliminate the guess work or just wing it, either way we all get to live with our decisions, as it should be.

Noah

 

[BoilerMan]

The numbers people throw around here are all over the place. Bret, you get free insulation from work, when I built my house I bought a retailer's entire stock of Dow Tuff-R (thremax, celotex) 1.5" for $13.50 a sheet. Needless to say, in my opinion as Noah said spray foam has it's place but is not the be all end all for home construction as it fail to address the thermal bridging through the SPF studs. One can either build a double wall and avoid the direct stud contact, or use a sheet good on the inside to stop the thermal bridging, this was what I did. If I had not landed the deal I did and had the capital to do so, I'd have gone the double wall and used Roxul, or cellulose.

To the OP,
Consider all things, a cool house in the summer w/o A.C., and less wood to cut in the winter, if you want a gasser, which is much more efficient, why not build a house that goes with the efficient appliance you are going to spend some coin on. My wife and I just had our first baby, and I'm glad I don't have to spend nearly as much time with the wood as I did before the Gasser, and the cool house in the summer is a bonus.

Bottom line it's your choice in the end, and there are some things that you can only do once in the construction of your house, trust me I know, it's now or never witht he design and insulation part, applinaces and the like can be changed, the building envelope is what it is, and is very costly to upgrade after all the drywall is up and finished, as others on here with old houses have said. EVERYONE, and i mean EVERYONE told me that I was going way overboard when I built my house, and now I can afford to heat it, and it's comfortable year round for about $5K extra up front and alot of time during the detailing, but in the big picture, it's only once, and my family and I will, Lord willing, have a lifetime to enjoy that extra 5K and about a week all said and done in the beginning.

TS

 

[Bret Chase]

when I built my house I bought a retailer's entire stock of Dow Tuff-R (thremax, celotex) 1.5" for $13.50 a sheet.
TS

1.5" tuff-R for $13.50????? that is the steal of the century!

Spray foam is all well and good for brand new construction... but it is still stupidly expensive in my area. In the past 24 years of doing commercial construction... I have only come across it barely a handful of times, all in refrigerated buildings. Foam in place makes any future work on the building a nightmare. You also end up either running all wiring in conduit... or just end up plain screwed if you want to change anything... ever.

In our industrial projects... there's been a big increase in SIP's... with the exception of the ones who have to shed a lot of process heat... With wood structured commercial... there's been an up tick in densepack cellulose. Most currently are going with the fiberglass/Low-E approach in the walls.

As I have said before, the code we've had to build under since '11 requires R50 in the ceiling, R23 in the walls and a blower door test. *Not* being "tight" really isn't an option for us...

 

[BoilerMan]

I've worked in the onstruction feild as well on and off in the past few years, and I know what you mean by foam and then there are no options for anything. Thats why I'm advocating sheet good foam, spray foam has it's place like rim joist areas or stone foundations. It is really expensive and makes a huge mess when things have to be taken apart.

TS

 

[BoilerMan]

1.5" tuff-R for $13.50????? that is the steal of the century!

Spray foam is all well and good for brand new construction... but it is still stupidly expensive in my area. In the past 24 years of doing commercial construction... I have only come across it barely a handful of times, all in refrigerated buildings. Foam in place makes any future work on the building a nightmare. You also end up either running all wiring in conduit... or just end up plain screwed if you want to change anything... ever.

In our industrial projects... there's been a big increase in SIP's... with the exception of the ones who have to shed a lot of process heat... With wood structured commercial... there's been an up tick in densepack cellulose. Most currently are going with the fiberglass/Low-E approach in the walls.

As I have said before, the code we've had to build under since '11 requires R50 in the ceiling, R23 in the walls and a blower door test. *Not* being "tight" really isn't an option for us...

It was from MPG (Maine Potato Growers CoOp) when they were getting out of the building materials part of their business. I split the inventory with my FIL who has many apartments and the like so he wanted the thinner stuff. I bought 2" for the north wall at $25 per sheet.

TS