Basement walls

[jeepinmatt]

Getting ready to build a new house, and trying to decided between regular poured concrete basement walls vs insulated concrete forms. Poured walls are gonna be about $36k. ICFs about $51k, however, that comes with insulation and inside and outside already firred out. My engineer gut says ICFs are the way to go, and that at least 1/3 of the $15k difference is offset by the savings later in the project. Also, I considered doing the first floor with ICFs, but the quote was $24k for just the 1st floor exterior walls. I think from a livability standpoint (insulation and sound damping), it's probably a better value since that's where we'll spend all our time, but I imagine $24k is about $20k more than 1500sqft of studwall and insulation.

 

[braxton357]

What happened to just adding on to current house? Seems pretty pricey for some basement walls

 

[RatLabGuy]

So just to be clear, aside from the in-wall insulation, the 15k difference (in the basement) also means having the interior walls completely finished?
Or just studded? As opposed to having to go back later yourself and put up a layer of XPS (or whatever) and wall in front of it?
XPS is not cheap, I know typically its advocated to do 2" thick to get a good enough R and operate as a vapor retarder, the cost of materials to do that + firring is a couple thousand in materials alone. Then its a question of whether you want to save $$ by doing that part yourself later.
At this point in my life I'd probably just pony up the xtra $$ to be done with it AND have it done the better way.

 

[broncosbybart]

How many linear feet of wall? Just curious as 15k is a lot of coin.

I don't see ICF construction on any plans we do. It's all poured concrete with 2x4 furring on the inside for insulation. My vote is for this and invest your money in other stuff that will really make a difference like the windows, roofing, and high quality exterior trim and boxing. People will never see the basement and the value added there. You will resell the house.

Use spray foam in the attic if you really are concerned about heat transfer. That is where it happens. 2x4 vs 2x6 exterior wall construction is a never ending debate. You can go either way there.

Oh- and what do you plan on for heating and cooling?

 

[paradisePWoffrd]

I can't speak to the difference but Superior walls could be another option. I've heard good things about them, if you can handle their timelines.

 

[RatLabGuy]

I guess 2 important questions here are (1) what is your intended use of the basement - will it be immediately finished off and used as living space, or just usual basement junk storage etc and (2) is it all completely subterrain, are you expecting any issues with moisture etc

 

[XJsavage]

Just curious as to the expected lifespan of an ICF.
I also used to work for a company that open/close foam shot basement walls all the time and I got good enough at it that I could shoot a consistent 1.5" of closed cell between firs in a 2500 sqft basement, full perimeter 8' ceilings, blah blah blah, pretty quickly.
However, if you have any rodents get in, they love to chew holes in it and build nests.

 

[jeepinmatt]

What happened to just adding on to current house? Seems pretty pricey for some basement walls

Adding on was going to cost more than just building separately because of the extra square footage due to how we wanted it oriented. That price includes digging basement and footings, and all concrete for walls and 1500sqft of slab.

So just to be clear, aside from the in-wall insulation, the 15k difference (in the basement) also means having the interior walls completely finished?
Or just studded?

Insulated and studded, inside and out.

How many linear feet of wall? Just curious as 15k is a lot of coin.

My memory says 192ft but I don't have the plans in front of me.

I guess 2 important questions here are (1) what is your intended use of the basement - will it be immediately finished off and used as living space, or just usual basement junk storage etc and (2) is it all completely subterrain, are you expecting any issues with moisture etc

1. Unfinished for now, may eventually finish it.
2. Front is completely subterranean. Both sides will be 50% subterranean. Rear will be walkout.

 

[palmetto zuk]

Let me know what you decide and I’ll come up, drink all your beer and draw a dick on the basement wall.

 

[josh m]

Let me know what you decide and I’ll come up, drink all your beer and draw a dick on the basement wall.

Now with friends like that^^^^............

 

[shawn]

What's the apples to apples cost? Add XPS or EPS and furring to the CIP wall, then go with whatever is cheaper. Sprayed polyurethane would also be acceptable.

 

[rabb11d]

I can't speak to the difference but Superior walls could be another option. I've heard good things about them, if you can handle their timelines.

We have superior walls, they are great. Would absolutely use them again. I have no hvac in basement and have no moisture problems. Temp stays 2 deg cooler year round. Let me know if you have any questions. Lifetime warranty I think.

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[shawn]

I have no hvac in basement and have no moisture problems. Temp stays 2 deg cooler year round.

2 degrees cooler than what? What's the RH? Is it static year-round, or does it fluctuate with the seasons?

 

[rabb11d]

2 degrees cooler than what? What's the RH? Is it static year-round, or does it fluctuate with the seasons?

Cooler than upstairs set temp. I'm not sure what RH is? Pretty much all these acronyms where over my head.

No insulation between basement and upper floors, house is spray foamed.

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[RatLabGuy]

Cooler than upstairs set temp. I'm not sure what RH is? Pretty much all these acronyms where over my head.

No insulation between basement and upper floors, house is spray foamed.

Sent from my SM-G950U using Tapatalk

Relative humidity.
Basements are always more humid than the rest of the house, especially in the summer when the air is naturally more moist.

 

[shawn]

Basements are always more humid than the rest of the house, especially in the summer when the air is naturally more moist.

Basement RH will spike in Spring and Fall, because the HVAC in the house runs less frequently. AC in the summer keeps the interior humidity down. With no insulation or air barrier between the house and the basement, the basement basically tracks what's going on upstairs.