lewis, if you re-read my original post you will see the system I'm asking about (which is not the Building Sciences way, but which I saw on the DIY show) has the housewrap against the foundation wall surface, on the outside of the insulated stud wall. I guess the idea was that the house wrap is not a vapor barrier, so the only vapor barrier is on the warm side of insulated stud wall, and also as house wrap is a good air infiltration barrier, it would also provide a contact barrier between the wood studs and the concrete. Any ways, as I said before, I'm going with the Building Sciences system. However, i have decided to also incorporate the house wrap. Here's what I've done on the one wall already. I applied continuous house wrap on the wall and extended it well up to the top of the rim joist to the underside of the subfloor and sealed the edges with acoustic sealant. I installed 2" thick foam 8' x 4' boards horizontally on top of the house wrap, also taking it up into the rim joist (double thickness here) and sealing the edges with spray foam. Laps between the sheets were sealed with spray foam and Tuck Tape. The stud wall was installed against the foam boards, the sill plate sitting on foam isolation srips. I'll be installing the insulation batts and the wiring next, followed by the drywall and alkyd paint. No vapour barrier. For the cost of the house wrap, which I bought in bulk, I think it's a double protection against air filtration, along with the foam board barrier. I don't believe there is any conflict here with good practice. Ted

Two issues are being confused here that don't necessarily have the same answer: 1) Temporary protection of the wall over the winter, best achieved, I suggest with loose tarping or a synthetic non-perforated UV resistant housewrap, which may have to be repaired in the spring. 2) Composition of the finished wall. Without actually being topped with stucco, this will not effectively withstand repeated direct wetting over the winter. Even the #30 paper (which is really just what #15 was years ago) is not designed for direct exposure. As for the final composition of that wall, what you're missing is the air gap that can only be provided by a three-dimensional plastic drainage mat. Anything else means a high probability of failure and repeated failure when it's "repaired" by just repeating what was done the first time. See here Martin Holladay's extensive coverage of the best way to build a EIFS wall as determined by building scientists and specialists. (Why anyone bothers anymore with EIFS--as opposed to traditional hardcoat stucco--boggles my mind. But that's another matter.)

The 1.3 R value is HUGE on a floor. Imagine your concrete slab as a HUGE refrigerator. And imagine it is left with the door open and running full throttle 24/7 for DECADES. That's what a slab is. We call it a heat sink. Because heat SINKS into it (never to come back out). What you want to do is COMPARE the COST of the DriCore R and the TOTAL RENOVATION cost of the in-floor radiant heating. The 'extra' $1300 for the DriCore is ONLY what you pay for. Leave the heating in the home as it is. I'm not kidding. Us the DriCore to UPGRADE the insulation in the home. And continue using the heating system you have. Now compare the cost of the HYDRONIC heating system purchase and installation with the DriCore R. I'm going to guess there is a HUGE difference. If you do NOT install SOMETHING insulating over that slab, you are going to heat the refrigerator and the EARTH below it. You are going to make some worms VERY happy....nice and toasty. You must have some form of heat break. Gluing plywood to an old slab isn't going to get this done. And this is precisely why the cost of RETROFITTING a hydronic system over a slab is one of the MOST EXPENSIVE upgrades you can do. The cost to do this properly (which means removing an inch of concrete, adding an insulation barrier like cork and then adding the tubing and then pouring new concrete) is exceptionally expensive. Trying to figure out a DIY level hydronic heat retro-fit over concrete slab is very tough. You have already stated you will be adding 2" of flooring height. But where is the HEAT BREAK? The cost of heating a heat sink (your concrete) is VERY HIGH. You will not see any savings. It might even become more expensive. Who has 'sold you' on the retrofit hydronic heat over concrete slab??? I'm in Canada and have had people in Northern Saskatchewan (1 hour drive south of the Territories). They routinely reach -40 C (same as -40 F). The basement never reached 16 C (60 F) in the winter time. They added 6mm cork (1/4") over the basement slab then added 11mm cork flooring over that. The basement was the warmest space in their house. It sat at a comfortable 22 C (72 F) without any change in their lifestyle (setting on their thermostat sat at the same place all the time). I saved them $25,000 because they were going to do the hydronic heat (properly). Not bad for a day's work (talking on the phone with them = 4 hours). All they needed was a regular heat source and some INSULATION over the slab. The 6mm cork underlay = the same as the insulating foam in the DriCore R (1.3 increase). The 11mm cork floating floor = same again (another 1.3). A regular heat source PLUS insulation over cement = warm spaces PLUS reduced heating costs. Nothing else needs to be added. No expensive retro fit (which needs to have the concrete jacked out and the insulation added then the tubes sunk in cement). This is the POWER of insulating a HEAT SINK. It's like turning off the refrigerator AND throwing down some carpet. Remove the chilly iceberg and you will automatically save money. It's your call.

Tar paper is the underlayment of choices according to the various cedar shingle associations. Tyvec works well too. That said, that is not a good location to learn the cedar siding trade and is best left to a contractor (not a painter) http://www.cedarbureau.org/installation/sidewall-installation-manual/ Underlayment - The CSSB recommends No. 30 felt (ASTM D226 Type II or ASTM D4869 Type IV) underlayment material. Apply it horizontally, with a staple gun, starting at the base of the wall, with a 2" horizontal overlap with each succeeding course, and a 6" overlap vertically when starting a new roll. Wrap the felt underlayment 4" each way around both inside and outside corners