Cinder Block Interior Wall Insulation Question

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sgwilliams

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I'm new to these forums and would like to say hi to everyone before I get started.

My wife and I just purchased an old home built in 1948. It was built by the little old couple who lived in it til 3-4 years ago as the man passed away and the wife was put in a home. They had been sick for a few years and neglected the home very much because they was not able to do anything due to their age and health. One of they're grand kids lived in it for a few years and nearly destroyed what was left. They lost the house to the bank which gave me the opportunity to step in and purchase it. The house is in zone 5 about 1-2 miles east of Lake Michigan. The winters are harsh and the summers are usually humid and warm. I'm doing all the remodeling myself as my accounts are tapped due to paying cash for the house.

The original home is a cinder block home with slab cement foundation and four exterior cinder block walls. In 1974 the couple added a large living room and two bedrooms on a 4 foot crawlspace and stick built walls on the east side of the house. This portion of the home is livable and was easily remodeled. They also added a two stall garage on the west side of the home. Which leaves the North and South exterior walls, the East and west are now interior.

My question is on the original cinder block section of the house. I currently have this portion off the home down to stud & Cinder block and have removed all the plumbing as it was all cracked and broken due to freezing. The plumbing & electrical is not a problem as I already have a plan and have enough experience to complete that myself. The cinder block exterior walls are bare (on the interior) and have had the drywall and furring strips removed, the ceilings are also down to stud. The exterior of the cinder blocks have wood paneling siding which is in good shape and just needs some paint.I peeled back the paneling and seen that it is just connected to the bare cinder block with furring strips.

I need to construct 2 x 4 walls on the interior of the North exterior block wall so I can run my new plumbing and electrical thru. I would like some advice on how to insulate this properly so there is very minimal moisture inside the wall.

I added a photo of how I was thinking of proceeding with this. Any help or advice on this would be greatly appreciated.

wall construction1.JPG
 
Your plan will work, but if you have a slab on grade it will not. You need to put the insulation down past the slab and break the continuity...otherwise, you end up with moisture issues at the bottom of the wall because of thermal bridging.

The best ways to insulate a Block house, is actually from the outside, they are just a tricky house to do properly.

If your ready, this is the Pro's answer to your question, and ony you are the one that can understand your home, and the way it lays out...
http://www.buildingscience.com/documents/digests/bsd-106-understanding-vapor-barriers

Good luck , and welcome aboard.:beer:
 
inspectorD, thank you for the great advice. The slab foundation has a perimeter wall that is 2-3 feet below grade then the slab was poured inside this perimeter. The slab is about 6 inches thick. I have already removed quite a bit of the slab to run a new sewer main and all the plumbing that goes in the home. Under where I installed the new plumbing was sand that I packed down, I then put a 6 mil plastic over the sand taped the seams and filled it with 6 inches of pea gravel. After I packed and leveled the pea gravel I put 3/4" thick pink Polystyrene insulation and taped the seams. Added rebar to the top of the insulation and then poured the concrete over this. I did not do this under where the new stick built walls will go except for where the sewer main goes outside.

I know from my research that it's a no-no to have wood contact the cinder block or any concrete. I was going to use a 1/4" thick polystyrene pink insulation strip under the bottom plate, which I planned on using interior friendly treated lumber for. I would also use the 1/2"-3/4" thick polystrene for the walls, I haven't quite decided yet. there would be a 1/4" gap between the 2x4 wall and the polystrene insulation. I would put a bead of spray foam insulation at the bottom plate to fill in the 1/4" gap between the 2x4 wall and the polystrene insulation. This will help keep the moisture out of the wall. We have been in the house for almost two years now and I have never seen any hint of moisture coming up from the concrete anywheres. The weeping that I have read about should not be a problem. What are your thoughts.
 
My thoughts??? :D

It sounds like you have a handle on the project, your sole goal is to keep any moisture from being trapped behind that wall. It needs to escape if it gets trapped by means of evaporation. However...if there is NO cellulose based material to get wet, you may be ok.
I would increase the r- value of the insulations, just to get away from any condensation or moisture build up issues.
Remember the block walls used to be the insulation, which means any dew point was probably being reached inside the hollow cavities, and drained down and dried out. Also, exterior of the Block has furring strips which basically make a rain screen wall which ventilates pretty well on hot sunny humid days. It creates a sort of convection behind the siding and wicks some moisture out the top of the wall.
This is why block walls are a tricky subject, and never easy.
Another trick, is to Also try to keep condensation to a minimum. A dehumidifier in the summer may help with that. I am guessing being East Of the lake, it may get a bit humid.
Block walls are now going to be on the outside of your climate controlled zone, which means we dont know what will happen at certain stages of weather, until you go through a cycle or two. So with that in mind, just pay attention to your upgrade, and see how it is being affected.

Not being there seeing what is missing in the entire envelope/project area, is where you have to make decisions based on what the article I gave you is advising.
I think you should give it a try, but just remember the more continuos your envelope, the better.
 
I appreciate all the input it has helped me greatly. I do also plan on using a product called Drylok Extreme on the interior and the exterior of the cinderblock to help keep the moisture from penetrating the wall. Just a little extra insurance. Beers are on me. Thanks :beer:
 
Should be using 2" foam against the foundation for it to have any effect.
That picture is missing a vapor barrier on the inside wall.
Moisture issues with foundations need to be addressed on the outside not the inside.
Rim joist need to be insulated.
 

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