How is the subfloor installed at the entry door area? 

If the floor joists are attached inside the wall, does the subfloor go out over the ICF wall opening at the entry door? 

Is the entry opening lowered to allow the joists to go even with the outside wall as in normal platform framing? 

Is it handled some other way? 

If anyone has pictures or drawings of this detail, I'd appreciate seeing them.

 

Thanks,

Bruce

Re: "If the floor joists are attached inside the wall, does the subfloor go out over the ICF wall opening at the entry door? "

You can run the subfloor on out over the ICF wall if you want to. This will require your opening to be slightly bigger of course but will allow you to place tile or whatever on a very flat surface.

Re: "Is the entry opening lowered to allow the joists to go even with the outside wall as in normal platform framing?" I wouldn't do this as this will somewhat significantly break your thermal envelope by replacing ICF with wood and foam at the floor."

Let me know if I didn't understand your question correctly. Regards.

Thank you TexasICF.  It sounds like you understood the question just fine.

 

Your answer gives me the impression that you do not run the subfloor through the opening.  I'd guess your install would have the subfloor even with the bottom of the door opening.  If that is the case, does the door threshold just get installed directly to the concrete core and insulation of the ICF?  If so, what fills the gap between the subfloor edge and the threshold.  It would seem that the gap would consist of the ICF insulation and some concrete core?

 

Your help is appreciated.

 

Bruce

Sorry to be a little vague - wasn't sure i had the picture. I've seen it done a number of ways. Subfloor extended out as well as concrete poured as part of the porch all the way to the subfloor inside with a step down. In both cases you have created a thermal bridge under the door that might make your floor a little colder, warmer etc. I've attached a couple of possible approaches for you. The one I like best is probably a "hybrid" showing the ICF cut to two different heights -- allowing a thermal break under the door. Also, the "nails" shown need to be longer to do their job properly and hold your buck material in place. Detail 1 is definately going to bridge temp to the floor while detail 2 will perform much better. Regards

Bruce, here's what I did. It's probably a little bit unconventional, but it worked. I used ADA (low profile) door sills, but that shouldn't change the approach. After thinking about several ways to do the doorways I opted to go with concrete sills. The sill extends to the outside about 2" and extends downward to lap over the top edge of the dimple membrane. They are sloped about 1/4" from inside edge to outside. I plan to eventually coat them with an epoxy sand concrete finishing product.

The subfloor was cut back at the door way to about halfway across the ledger board. I then put a strip of subfloor material, after the concrete was poured, to extend the subfloor surface about halfway or so across the inside foam of the ICF block. This created a thermal break between the concrete and the subfloor. The inside finished height of the concrete sill is about 1 1/4" above the subfloor. I put a wood spacer under the threshold to support the inside edge. There is about a 1" gap between this spacer and the sill that is filled with foam. The thresholds have thermal breaks built into them. All the exterior doors have tile coming up to them so the tile was sloped up to meet the threshold.

I hope the pictures give you a pretty good idea of how I did it. Sorry I don't have pics showing more details. Last pic is the next message.

You can kind of see the tile sloping up to the threshold in this pic.

TexasICF, thanks for the details.  That cleared things up for me.  Somehow I missed them on Nurdura's site.   Now I know where to find them.

 

Dmaceld, the pictures and description are excellent.  I like that your doors are flush inside so they can open fully.

 

Do you by chance have a picture you'd like to share of the door exterior to see how you handled the finish there?

Here's a couple. I made the frame with 2 2 x 6s over a 3/4" blue board. I did this to be able to use standard 6" wall pre hung doors and have a good thermal break around the door. The exterior is finished with 1 x 4 Truwood trim around the inset, Hardiplank in the inset, and standard brick mold on the door frame.

Dmaceld,

 

Nicely detailed.

 

Thank you,

Bruce

dmaceld,

I see that you used 3/4" Styrofoam (blueboard) insulation between the wood members at the door.  Do you see any problems if someone wants to use thicker blueboard?  What would be the limiting factors in using thicker blueboard insulation with your system?

Actually I used 1" blue board for a total thickness of 4". Add to that 1/2" drywall and it matches the jamb width of a door for a standard 2 x 4 wall, not 6" as I stated above. The only problem I would see with using thicker styrofoam is matching the jamb width of standard pre-built doors. If custom sizing a door jamb is not an issue than that's a non-concern.

As I see it the limiting factor as far as styrofoam thickness is assembling the sandwich beam, as I called it on my drawings, and keeping it square and straight and the 2 x 6s in line with each other. I prebuilt the beams. The biggest problem I encountered was working with twisted 2 x 6s. Some of the beams ended up with a pretty good twist which complicated the process of installing them in the bucks and hanging the doors square and level. I glued the wood and styro together so keeping the 2 x 6s lined up while screwing them together was a minor challenge as they all liked to slide around while the glue was wet.

As an aside, because of the restriction against untreated wood being in contact with concrete near grade level, and the propensity of wood around a door to rot at the bottom from getting wet from rain, I added a piece of Trex plank to the bottom of each of the vertical 2 x 6s.

dmaceld,

I can get away from the problem with the 2x6's twisting by using TimberStrand LSL 2x6 studs.