Hiding (and maybe insulating) the foundation

[BigMish]

I am building the 1 ½ story  20' Cottage and using a crawlspace foundation. I don't like the look of exposed concrete foundations and I'm considering insulating the crawlspace. Therefore, I'm considering two alternatives to the foundation illustrated in the plans.

Please take a look at the attached sections (not to scale) and following questions:

Do these look right?
How low can the wood siding go? Could it go below grade (and just be replaced every few years)?  Is this a potential code issue?
With regards to the foundation with insulation I got this section from a book but the sill sitting of the foundation wall like that looks sketchy to me; would it have any impact on the framing?

Also, I'm new here: would this post be better posted to the "General Forum" board?

Thanks, Mischa

[borgdog]

Well, I know that Glenn the underground house builder will probably weigh in, but I would not have the PT ply extend to the ground.  Great invitation for bugs, even with all the treatments.  I personally like a stucco like treatment, or stone faced.

[jraabe]

Yes, any non-treated wood must be at least 6" above grade. Also foam insulation is quite tender and must be protected from physical deterioration.

Here is a detail we did for the "Superinsulated Design and Construction" book:

[MountainDon]

...like a stucco like treatment...

Around here (desert USA) it seems the majority of stuccoed homes run the stucco right down to the ground. I've noticed a few of them have problems down low if the ground is kept too moist as in over watering your plants and shrubs right along the home wall. I've seen flaking off and efflorescence (white mineral crap on the surface from evaporation). Not nice. If it's not against code to have stucco go into the ground it ought to be. IMHO.  

What about Hardi-Plank siding? Will it wick moisture up if below grade?

[jraabe]

You could use cement mill board or hardiplank cement siding. Others have used metal (such as corrugated roofing) flat stock (such as anodized aluminum) and Dow makes a trowel on plastic cement coating designed for sticking to blueboard or pink board or any of the extruded polystyrene insulation materials (which is the material you want for direct embedment in soil).

You can also use PT plywood. Anything that will protect the insulation from abuse and UV radiation.

One of the most handsome treatments is to use a wide tapered drip stop at the bottom of the siding and then do flared rock work below. Very classy. Looks like the CCC shelters and forest service buildings built during the depression.

[glenn-k]

Nice construction details, John.  Similar to the bigger house I'm working on - but instead of insulation we are going to put the plastic thimble drain board with the geotextile fabric on it then french drains around the bottom.

[BigMish]

John, I goggled CCC shelters and that is a really nice look indeed.

I amde up a section of what I understand you to mean. A few questions:
Does the attached section look right?
Does the rock work sit on a ledge or just sit on the fill to that point?
I've got no masonry experience, would it be a regular mason whom I would use to lay the rock work?
Is that what you meant by a "drip stop" (just flashing, really), would that palcement be right?

Thanks all for all the responses. It's really encouraging to see how lively this board is.

.M

[jraabe]

There should be something supporting the rock work other than the soil. If it is planned from the start you can build a ledge into the footing wall a few inches below the finish grade and have that support the weight of the rock. If you are in a shallow frost area then you can just carry the rock down to the footer. Of course this is for real rock. You can do stick-on simulated rock without any support. It doesn't look too bad. You see it on $1,000,000 houses all the time.

The flashing should be from behind the siding out over the rock work. Usually the housewrap would go over the flashing so that any moisture getting through the siding goes down the housewrap and is carried out over the rock work by the flashing.

[Zero_Punch]

Although just in the planning stage and only yesterday ordered the 11/2 story cottage plan I have given considerable thought to exposed concrete foundation as we plan on a daylight basement or at least partial depending on ground slope. The wife loves the look of dry laid stone but I have no desire to learn and as she says I'm too cheap to hire it. So I have looked for alternatives and have found one that may be of interest http://www.flex-c-ment.com/wall-system.htm I have no idea of the cost but it appears to be more in line with what I'm familiar with as I've done a bit of stucco, plastering and other work with cement compounds. There is also another site that offers form liners if one is going with a poured foundation it's http://www.greenstreak.com/Div3/FormLiner/formliners.asp

John

[glenn-k]

Thanks for the links, John and welcome to the forum.  Looking forward to seeing your progress.

If interested in learning more on dry stone walling, here is a link to a good online book Bart posted a long time ago.  

http://handbooks.btcv.org.uk/handbooks/index/book/61

Be sure to click on the sub topic lines in the index at the left as it isn't real obvious that there is a ton more information in it as you open the topics.  Hope that makes sense.

[Sassy]

I viewed the gallery pics on Flex-C-cement - some really nice work!

[Amanda_931]

If you don't mind it going S..L..O..W..L..Y slipformed concrete will give you the stone look without learning to lay stone.

Infomercial from Thomas Elpel (not a bad source) for his books--he published a variant on the traditional, with insulation--someone else was later the first to try it. There are links at the link:

http://www.hollowtop.com/cls_html/do-it-yourself/stone_masonry.htm

A couple of books available new--

http://www.amazon.com/Stonebuilders-Primer-Step-Step-Owner-Builders/dp/product-description/1552092984

This is probably the most recent (there are others available more quickly)--read the reviews on this, a couple are pretty funny.

http://www.amazon.com/Building-Beautiful-Inexpensive-Stone-House/dp/159526020X/ref=sr_1_6/103-8113167-9527067?ie=UTF8&s=books&qid=1174271059&sr=1-6

Helen and Scott Nearing's house(s) was (were) made this way.  Karl and Sue Schwenke also made one, IIRC without insulation, and apparently loved theirs as well.  I know people in this area who did these as well.  They may have learned from a now out-of-print by the Schwenkes, although I think the first one was in process about the publication date of this book:

http://www.amazon.com/Build-Your-Own-Stone-House/dp/B000LWVQGE/ref=sr_1_1/103-8113167-9527067?ie=UTF8&s=books&qid=1174272032&sr=1-1

[BigMish]

If I went with an externally  insulated crawlspace (but no insulation external the house stud walls) and thus hung the sill off the front of the foundation wall by the depth of the insulation, would there be any necessary structural changes as a consequence (other than that the foundation dimensions would decrease by the insulation depth)?

[John Raabe]

You can cantilever a 2x6 sill plate up to 2" to cover foam insulation and have the framing align with it above. (As you diagram in the right hand drawing of the first post.)