Frost-Protected Shallow Foundations are pretty much standard here in Sweden. Between 250-350 mm (400mm for a passivehouse) of s80-100 eps insulation is used under floors and 100-200 mm s200-s500 under footings.

here is an example of a common type of slab used in sweden http://www.passivedesign.org/supergrund

It looks good, thanks. I am curious why they don't attach the floor slab to the footings, at least in cases where the soil has poor bearing capacity.

I assume that there are also wings of foam that extend outwards from the footings? Otherwise, frost can get under the footing.

Some questions:

1) What are the characteristics of "hardcore" and what are the compaction standards? Any plate compactor or a certain size required?
2) What are the characteristics of "sand binding" and what does it do? Provide a little friction over the radon barrier? Or a cushion?
3) How is the ringbeam fixed in position both during construction and after?
4) Why are stainless ties used to support the reinforcing bar?
5) What are the characteristics of the "fixing nails" and how far apart are they spaced?
6) What is the earthquake plan for these foundations? It looks like they would just slide on the sand binder......
7) How is the home attached to the slab and ringbeam?
8) What is the fabric visible in images #6 and #7?
And, finally, how many of these components are required by building code? For example, is the sand binding a requirement or just good practice?

wow... alot of questions im going to try to answer them ..but my english is not good ...

1) What are the characteristics of "hardcore" and what are the compaction standards? Any plate compactor or a certain size require

the "hardcore" under swedish slabs are usually 150-200m layer of washed 16/32 mm gravel that is compacted with a 100 kg plate compactor (rule of thumb in sweden 100kg compacts 100mm) . After that we used 30 mm finer graver (not compcted)l for easier assembly of the edge blocks

2) What are the characteristics of "sand binding" and what does it do? Provide a little friction over the radon barrier? Or a cushion?

Probably for easier assembly of edgeblocks ... those pictures are taken in ireland and they do it a bit different than we do..the radon barrier for example is laid between 1 st and 2 nd layer off insulation in sweden

3) How is the ringbeam fixed in position both during construction and after

heres a youtube video :http://www.youtube.com/watch?v=6bzviF1CW20&feature=related Before pooring concrete you have to backfil with l gravel against the edge blocks

4) Why are stainless ties used to support the reinforcing bar?

To tie together the ringbeam and floor slab

5) What are the characteristics of the "fixing nails" and how far apart are they spaced?
Fixing nails are made of plastic and just holds the insulation together. I use more nails around the ringbeams and less in the middle of the slab.

6) What is the earthquake plan for these foundations? It looks like they would just slide on the sand binder......

Good question... it is not a problem here in sweden.

7) How is the home attached to the slab and ringbeam?
Another youtube video http://www.youtube.com/watch?v=3KunI3KaiDA&feature=related this is not the only way but its quite common.

8) What is the fabric visible in images #6 and #7?

So that the concrete dont stick to the eps if u want a conctrete look like this http://www.passivedesign.org/images/supergrund/e1_opt%202.jpg or http://www.supergrund.se/files/document/byggbskrivning1.pdf

9) well the sand or fine gravel that we use are not requred but helps getting the block nice and level and thats important. You dont need to use fixing nails but they help alot. Its not required by code

Theres many types of edge blocks available in Sweden. Supergrund uses U blocks. Most common are I blocks, F blocks, L,LE blocks and u blocks.

heres a pdf from sunolitt its in swedish... but have alot of pictures http://www.sundolitt.se/upload_images/50232EBA1E9E4666BEBD9EDDA7BD6529.pdf

4) Why are stainless ties used to support the reinforcing bar?

I will guess they are stainless because a portion of them are not covered in concrete - so they could rust through.

I see that the Sundolitt PDF shows several designs where the slab and footing are connected with concrete. But all of the drawings look like they are susceptible to frost getting under the footings.

http://www.jackon.se/dav/7513158a61.pdf shows how to insulated against it

wow... alot of questions im going to try to answer them

Thank you for the time you spent on this.

I'm interested in this as a way to build large numbers of small well-insulated homes in a cost-effective manner. But, there seem to be some barriers to using it over here. What are your typical requirements for seismic and high wind resistance? This construction looks like it has very little protection against either. Spectacularly quick and simple and well-insulated, though.

For those casual readers who don't want to see the (Swedish) video, the stick walls are framed on the finished slab and squared into position with a non-treated single sill plate and a quality sill gasket, then set in place with expansion anchors drilled through the sill plate.
The .pdf looks like it is depicting standard insulation wings for shallow frost-protected foundations (in Sweden).

well ...  theres earthquakes in sweden but there only like 2.8 and once in awhile theres a 4.1 and the strongest tornados has barely been a f1 in sweden... so not a big problem here.


edit : Greg Lavadera and  Scott Hedges have researched swedish house construction for a couple years. check out gregs blog : http://blog.lamidesign.com/search/label/letters%20from%20Sweden

Any idea how types 100,200,300 EPS compares to the North American types in compressive strength an U value?

Yeah, the rating over there is in kPa, where 100 kPa is about 15 psi, 200 kPa is about 30 psi and so forth. EPS is about R4 per inch, but you need to check with the particular product for the last word on that.

http://www.sundolitt.se/upload_images/50232EBA1E9E4666BEBD9EDDA7BD6529.pdf

on page 6 you have short and logterm characteristic compressive property

F kk = karakteristisk tryckhållsfastighet = characteristic compressive property short term
F kl = longterm (50 years)

brottgräns =Ultimate strengthbreaking strength
bruksgräns =serviceability limit (1)

(1) Compressive stresses equal to 3% totaldeformation,  t, or 2% creep strain,  ct, after 50 years of loading time (to check for serviceability limit state),

This method looks interesting. It would be suitable only for light weight framing, e.g. wood framing, which I am not a fan of. Also I don't like the slab not being monolithic with the footing.

I like frost footings and foundations.

you can use L edgeblocks instead if u want a monolithic slab

Posted By ICFHybrid on 12 Aug 2012 12:06 PM
Yeah, the rating over there is in kPa, where 100 kPa is about 15 psi, 200 kPa is about 30 psi and so forth. EPS is about R4 per inch, but you need to check with the particular product for the last word on that.

So our type II is equal to their type 100, and type IV is equal to their 200. I guess one would use type IX for a replacement for their type 300 but what is the pricing on type IX?

I just used a small amount of Carlisle Type IX rated at "25-33 psi", according to the specsheet. The order was 320 board feet at $0.57/board foot.

300 kPa is more like 43 psi.

~2 years ago I purchased Foam Control Type IX EPS with Perform Guard termite treatment for under my basement slab. The cost was ~$0.35 per square foot for 1" thick EPS. I purchased ~2200 sq ft.

http://www.noarkrcontrol.com/downloads/brochure/Foam-Control-EPS-with-PerformGuard.pdf

Posted By MikeSolar on 12 Aug 2012 04:41 PM

Posted By ICFHybrid on 12 Aug 2012 12:06 PM
Yeah, the rating over there is in kPa, where 100 kPa is about 15 psi, 200 kPa is about 30 psi and so forth. EPS is about R4 per inch, but you need to check with the particular product for the last word on that.

So our type II is equal to their type 100, and type IV is equal to their 200. I guess one would use type IX for a replacement for their type 300 but what is the pricing on type IX?

It looks like our Type II EPS (nominal 1.5# density) is roughly equal to their Type 100, our Type IX (nominal 2# density) is roughly equal to their Type 200, and our Type XIV (nominal 2.5# density) is roughly equal to their Type 300.

http://www.epsindustry.org/sites/de...0Chart.pdf

prices in sweden for eps are bout:

60-65 skr ($ 9-10) m2 for 100 mm S80-S100 used under floors on slab 600x1200 mm or 1200x2100 mm for a single home .. cheaper if you buy for several homes same with S200-S300 mm eps
106-120skr ($16-18) S200-S300 100mmm used under footings and stem walls .

135-300 skr for edge blocks per meter depends what type and if they have a glued cement bord or are cement rendered. Inside and outside corners cost more.. cheaper if you buy for several homes

Here is youtube clip on how they make L edge blocks .. not that complicated imho http://www.youtube.com/watch?v=1iFLD3lIlyg&feature=player_embedded#t=152s

afaik no one makes theese in usa ... who is going to be the first ?

no one makes theese in usa ... who is going to be the first ?

We just don't have that many places with over 10,000 heating degree days. And then there are those seismic issues. What about Canada?