[GreenMagic]

Rot replacement wood framing T111 cut out and use CMU block? 2.25" foundation + grade

Hi all!

Been wanting to join a home DIY forum for awhile and today's the day

I have a non load bearing side of house with a standard full basement with partial walk out bulkhead and half stick wall on one side only of house.

Rest of house and garage is fine.
The dumdums built this house (or modified it), with half high foundation wall that only cleared the grade but 2.25"!
Then they thought it was a good idea to simply lay T111 over the the edge of the foundation to grade / ground level. No flashing, no housewrap. They thought it might be nifty to submerge a 4x4" PT lumber right next to the wall and call it (well, maybe they may have put in pebble / rock stone there after that - hard to tell with soil and grass that's taken over.

MY QUESTION (and my thoughts):
At first I panicked when I pulled the rotted T111 and saw the sills are tunneled through with carpenter ants.
Then I thought "I'm gonna have to pour concrete to raise the wall at least 10-12" above grade"...
Then I thought 'Concrete block!!"

So that's what I've been thinking of doing:
chopping out the eaten up sill plates, and then cutting out the stud framing and install one row of 8" concrete block. Then pouring the holes in concrete and have maybe 4-6 5/8" J bolts to install the new PT sill plate on.
Basically: shorten the wood wall and try to in essence raise up the foundation height. Basically build a 'stem wall' (?) of CMU above the existing full foundation where they cut it too short.
I have to remove the sills anyway. We are talking 10' 3" of that run between full height foundation and the bulkhead door, and about 4' on the other side of the bulkhead door.

I also have to remove two small windows anyway. Then maybe chop 2" from the headers to make them about (2) 2x6" headers. The windows have (2) 2x8" headers on a NON load bearing side of one story home with short attic only above living space and full basement. This way I could fit in a 4" solid concrete block under those windows to at least raised there height to about 10" off the grade.

I've attached some pics.
Thank you for any advice!!!

 

[GreenMagic]

Re: Rot replacement wood framing T111 cut out and use CMU block? 2.25" foundation + g

click on first picture to enlarge to read text easier.

I DO have (3) screw jack style temporary lalley columns types of thing that can support 12,000 - 14,000 lbs each. And huge wood blocks etc...
So I could easily support whatever I have to if need be. Although this is the gable side and not sure I even really structurally need a header over those windows for example (I read the JLConline site too).

I am starting complete re-siding project of Certainteed vinyl.
That's why I removed the rotted T111 here, to rebuild it. Had planned to housewrap (Tyvek) the main house and vinyl the whole main floor and above (why you see Tyvek around those main windows there).
I had planned to strip to studs and then install 7/16" plywood and then Tyvek and Grace Vycor for re-installing those two lower windows and then siding that lower level only with HardiePanel 4x8' sheets cut to size. THEN I discovered the rotten sills and it's derailed any progress. But that's why you see Tyvek above it (old pic), and I've put in 6 new windows in the house and tyvek wrapped it.

EDIT: Should have mentioned this home is in NH with 50 psi snow load factor I believe.

 

[GreenMagic]

Re: Rot replacement wood framing T111 cut out and use CMU block? 2.25" foundation + g

BUMP.

CAN I use concrete block and is that better than rebuilding with wood??
Is it BETTER to use only wood and rebuild it like it was??

The existing foundation only clears the soil / grade by 2.5".

Will I have issues bonding new concrete block and mortar to an 1980 built full foundation??

Thank you for any clarifications.

 

[3onthetree]

Re: Rot replacement wood framing T111 cut out and use CMU block? 2.25" foundation + g

I realize you have to replace the wood anyway, but that's a lot of work. Why can't you just lower the grade and pipe your downspouts somewhere?

If you were to add height to the wall, keep the header as is and get a smaller window.

 

[Bondo]

Re: Rot replacement wood framing T111 cut out and use CMU block? 2.25" foundation + g

I realize you have to replace the wood anyway, but that's a lot of work. Why can't you just lower the grade and pipe your downspouts somewhere?

Ayuh,..... Ideally, you'd replace the wood with ground contact P/T,......

Lowerin' the grade, I would do, regardless,.....

 

[Nealtw]

Re: Rot replacement wood framing T111 cut out and use CMU block? 2.25" foundation + g

As it is an outside wall it is still considered a load bearing wall, it is supporting the walls above it.

If the floor joists are going in the same direction as the rim you can just double the rim above with one 4 inches wider than the window.

Or just cut the one out from the outside and double it up and put it back in.

 

[GreenMagic]

Re: Rot replacement wood framing T111 cut out and use CMU block? 2.25" foundation + g

These are interesting suggestions.
I don't have downspouts that come out this area as it's gable end. Gutters go elsewhere.
I was planning to use PT wood for the sill with barrier on the concrete.
The inside of that room (window on right) is finished with fully finished and taped walls and ceilings, making access to upper joists more involved.

The other window on the left is unfinished shop area where I can easily access that outside floor joist.
All the joists run left to right in the photo. They are supported by triple string large headers that run away from the viewer angle. They have multiple lalley columns supporting along the way.

 

[3onthetree]

Re: Rot replacement wood framing T111 cut out and use CMU block? 2.25" foundation + g

I don't have downspouts that come out this area as it's gable end. Gutters go elsewhere.

I certainly see the yard sloping down, and a gutter dumping into this area, surely on the other side too (not shown in pic).

Maybe I'm misunderstanding, but if you are talking about a membrane on the CMU face, like to prevent infiltration through the CMU to poured transition, or the CMU itself, I only see damproofing/waterproofing only up to grade. Grade should be lowered and sloped away regardless. If you are planning on a 6" deep pool of water against the house you've got other problems.

 

[GreenMagic]

Re: Rot replacement wood framing T111 cut out and use CMU block? 2.25" foundation + g

I will take a look more at that downspout and grading there.
I meant a membrane over the final top of the new installed CMU single layer, that would go between it and the PT lumber sill.
I'm going back to house tomorrow to work on siding and make more measurements of that back area.
thanks!