Timber frame owner builder in NJ

[tkappeler]

It sounds like we are only days from receiving approved building permits! I am very excited. I am trying to nail down an excavator and concrete contractor before the weekend, then we can start clearing trees as soon as the weather warms up!

Does anyone have input regarding basement insulation? I am planning on putting foam boards under the slab. I think I will use 2" EPS foam under the slab. I need to insulate the basement walls but do not plan on finishing the basement until a later date. I could glue rigid eps foam to the walls as insulation but it would need to be finished with drywall as a thermal barrier. But if I have to drywall it, thenI would need to plumb and run electric, or have to rip it out later to finish the basement. Another option is spray foam, but I think it has the same requirements... I would like to insulate it now, because we will finish it in the future, but it seems there isn't much allowance for this. Any ideas?

I know when we built, NJ code required R10 on the basement walls but there was a change coming to raise the requirement to R12.5 or something like that. I was told that the new requirements and other code changes were delayed in 2013 because of Sandy. Not sure if the new ones are in place now or not. The most common technique I have seen are the insulation blankets similar to these. If you decide to finish the basement, you can build a wall inside this one to keep the blanket in place and easy electrical and plumbing routing.

One other option is ICFs as shown here

 

[emanaresi]

OK, I know its only been a few minutes, but the town just called and said the permits are ready, so as soon as this cold snap stops, we are taking down trees!!

 

[emanaresi]

Thanks, tom. the insulation blankets are not an option in our basement, I don't think they should ever be installed below grade...

We did get quotes on ICFs early in the process and the price was very high! Also, ICFs actually need to be covered in a thermal barrier as well, if the inspector follows the code book, at least.

 

[jk96]

We framed the basement then sprayed 2" of closed cell. It gives about an R13.5 and leaves room for electrical later. The closed cell also has a fire retardent built in. You can't get it to burn with a lighter. It will self extinguish. You would have to verify it meets code for NJ.

 

[emanaresi]

The only quote I have gotten so far for spray foam is $1.10/sq ft/in for closed cell they also suggested a spray on ignition barrier ($.85/sq ft!). I am waiting for a call fromt he inspector to see what he will accept. I can buy rigid foam WAY cheaper and glue it to the walls myself... Just need to figure out the best route here.

 

[BitChin1]

OK, I know its only been a few minutes, but the town just called and said the permits are ready, so as soon as this cold snap stops, we are taking down trees!!

Wow - congrats:cool2:

As for basement foam look at foil faced polyiso - here they allow it to be exposed but EPS/XPS need covered -

Also does code there require all exterior walls to be insulated?
Last question is do you have the plan for the basement finalized? If so you could do rough-in work for the exterior walls now and actually finish later - in our case we did this for a couple of rooms and extra cost was very minimal and significantly less than having the subs come back later.

 

[Ranger Rick]

Maybe you could use the superior wall system. Then you would have a precast basement wall that comes insulated.
Superior Walls / Products
I have read other threads where others have used it.

 

[emanaresi]

We do have the basement plans pretty well nailed down. I don't think they need to be insulated except above grade they do. I am am going to look into the polyiso a little more. I think the spray foam is just too expensive...

I considered superior walls early in the process, they are neat, just don't fit my needs on this project.

 

[tkappeler]

We do have the basement plans pretty well nailed down. I don't think they need to be insulated except above grade they do. I am am going to look into the polyiso a little more. I think the spray foam is just too expensive...

I considered superior walls early in the process, they are neat, just don't fit my needs on this project.

I think the codes require you to insulate the entire basement walls. Most states have adopted some level of the International Energy Conservation Code. For NJ, new construction must meet 2006 standards. Did you have to run a ResCheck to verify conformance to the code? If so, you pretty much cannot pass without insulating the basement walls.

I ran the ResCheck and if I left just one basement wall uninsulated, I failed and I R26 in walls and R45 in ceilings, very high efficiency windows, etc.

Not to open a can of worms, but you may want to confirm this with the township. I would hate for you to get all rough ins complete and ready to button up and have the insulation inspection fail because it's not done and then it could be a pain to retrofit. Just my :2cents:

 

[emanaresi]

No worries there, I do plan to insulate the whole wall.