Has anyone used foam board or other insulation on concrete foundation (basement) walls?  

 

How to you attach and what do you do to prevent moisture -> mold?

 

Is it really that effective?

No personal experience, but, some of the concrete houses use closed cell foam for the forms. They aren't wreck after the pour cures, but are left in place as added insulation. I have seen/read information that they can be used for in-ground applications (basements). So, armed with that, I would say that it can be use.

 

However, I would sure like to seal an in-ground application against water migration/infiltration. As for the mold you need moisture and air for mold to grow. If there is no condensation (i.e. basement) and it is kept dry, mold shouldn't be a problem. Outside shouldn't be an issue

2 hours ago, kmealy said:

Has anyone used foam board or other insulation on concrete foundation (basement) walls?  

 

yes.. often.. use extruded polystyrene..

 

2 hours ago, kmealy said:

How to you attach and what do you do to prevent moisture -> mold?

 

start the lay up w/ a "J" or a "U" channel at the floor.. put them in horizontally (channel and styrene)... spot glue the panels and add a "Z" metal at each 2' seam as a clip to hold the styrene and to function as a furring strip... continue up the wall... I like to hang rock vertical .. no butt joints and a lot less waste..

or go vertical...

seal the masonry...
fasten the metal to the wall w/ tapcons...

Z-Furring Channel | ClarkDietrich Building Systems

 

if this is a shop application sheath the walls w/ OSB before the rock.. nailers everywhere...

and since code/insurance/building departments see this as a shop..
Drywall  the sheathing...
hang it vertically as long as the seams for the DW and sheathing don't lay up on each other...
fire tape it...
paint...
here we are required to use "5/8 type X" DW...
the sheathing gives you any time/place nailers... you want something to hang right there.. go for it.. it'll be all cake and pie...
the styrene is about the most "R" value you can pack into the wall in less space...
Fire rock is self explanatory...
It will take a while for you to comprehend how comfortable your shop has become and how much less HVAC it will take to to get there...

Suggest you surface mount your electric in conduit...
you get to have what you want/need exactly where it needs to be and changes are cake and pie to do...
 

 

With this type of construction you can start in any corner and begin your sheathing/DW'ing head on down the wall... The drop for that wall then can be carried around to the next wall and carried on... Try not to match up sheathing and DW vertical seams...

the order is "U" channel (at the floor), styrene, "Z" channel, (continue sequence to the ceiling) and finish with a "U" channel at the ceiling.... vertically "U" channel the corners and also around the windows and doors...

 

I use 22/24GA channel.. anything less will compromise strength come "hang it on wall" time..
install the channels and "Z's" to the concrete/block wall w/ tapcons - often.. 12"OC is highly recommended and forget using a Ramset or Hilti... "blow outs" and poor "sets" will screw w/ the overall mission....
besides, tapcons are hold night and day better over shot in pins...

now hang, w/ screws, at least 1/2" sheathing on the wall, vertically... we use CDX ply over OSB because OSB won't hold fasteners nearly as well as real ply... this is the voice of experience here...
those that do use OSB use the true 1/2" plus and not the 7/16"... again, VOE...
w/ hanging vertically there is a lot less waste and seam placement is moot...

coming out of corner...
vertical "U" channel...
horizontal "Z's" and styrene...
vertical sheathing into the corner...
now install the other vertical "U" channel on the opposing wall.... continue on w/ that wall...
fit/finish/strength and ease of install is greatly improved... VOE...

 

 

 

2 hours ago, kmealy said:

Is it really that effective?

 

oh yes...

stops/nulls the heat sink action...

 

Note...
The rigid extruded polystyrene board (REP) is your new VB...
While you are at it... Cover any in ground foundation w/ polystyrene also... Hopefully the exterior of the foundation is already done... If not, do it when you can but just do it...... frost line here is 120''...
Ceiling, four feet of blown in would be nice... Thee will make a world of difference

Edited January 31, 20188 yr by Stick486

New construction....

We used to apply the rigid foam boards to the inside of foundation walls....IF there wasn't to be a basement.      Otherwise, BEFORE we'd back-fill the outside of the foundation walls, we'lay up a layer of the foam boards....often using the wall ties to attach the foam.   

 

Of course,,there was those "tilt-up walls" we made.....one layer of concrete ( with steel mesh and rebar) then as that layer was "placed"  we'd add a layer of foam boards, and "pin" them in place....along that to set up a day, as we'd add more rebar and other inserts.....and place the rest of the 12-14" of wall's concrete ( usually about 8" or so.  )Let sit for at least 2 weeks. then tilt up the wall panel and place it.    Stamping plant in Kalida, OH was one such building...The old Whirlpool plant down by Greenville, OH was another.....they used an epoxy foam "rope" to seal between the panels.   Then seal that with more epoxy.   Panels were usually bolted to a red/gray iron framework.     We'd cast the panels right on the concrete floor, to get a smooth outer face.

 

 

My daughter's neighbor (UP of MI where they get avg 250" snow a year) had a foundation poured with the insulated panes on both sides making the forms.   Found out one of the guys at church (who I knew was a concrete guy) does this a lot.  His company won second place for this at last week's "World of Concrete" convention.    But my walls are 20 years old.

they are called ICF's...

https://www.amvicsystem.com/insulated-concrete-forms

 

 

 

https://energy.gov/sites/prod/files/2014/01/f6/1_1a_ba_innov_basementinsulationsystems_011713.pdf

 

https://www.basementsystems.com/basement-finishing/insulated-wall-panels.html

 

http://www.homeconstructionimprovement.com/insulating-basement-walls/

 

https://www.basementsystems.com/basement-waterproofing/basement-insulation.html

The way I did it was to first seal the block (in my case) with two coats of Drylok. This was to prevent water vapor from coming into the heated/cooled space. I used 2" polystyrene foam, the Dow blue stuff in my case. I used a pressure treated bottom 2x4 plate with a foam sill sealer under it. I attached of top plate to the bottom of the floor joists above or to spacer between the joists when the wall ran parallel to the joists. Then I attached the 4 X 8 foam board with construction adhesive meant for foam. For studs I used 2x4s laid on the wide side so the combination of foam and studs thickness was 3 1/2". The studs where secured with tapcons. Had to get the tapcons at Fastenal since I need them to be 5 inch long. For receptacles, I carved out a recess in the foam to allow for standard depth boxes. Wall sheathing was 1/2 plywood. Ceiling was insulated with Roxul to help with sound deadening. 

plese check out 

https://insofast.com/explore/project-prep-before-you-install-insofast/

You should solve all your water issues first.  Then depending where you live (I am in Zone 5=R10) then I would use 2.5" insofast insulation panels.

They come pre channeled for electrical and they glue to the wall creating a thermal break not a bridge.  They also have moisture channels.

It is important that you insulate the rim joist fully and create a fully insulated space.  That will keep the moisture in the house from collecting on the cold block.

Drylock Extreme is what they recommend before the insulation the the glue they recommend is cerfitifed with Drylock Extreme.

You do need to cover any foam on the floor or wall wtih a 15 minute burn thru barrier (5/8" drywall).  But in the rim joist you do not need to cover it.

What I did was to get 2" foam and cut it 1/2" short all round to the space.  Then I put a dap of glue on the back and press it in place.

Then I take expanding foam and spray all around the permiter to seal the joists to the rim and the foam to the joists and rim.

It is very important to not use any metal in the cold concrete that is a thermal bridge and you will loose heat.

The 2" insofast foam is available at Lowes.