ICF basement walls

skyking · 01-09-22, 12:27 PM

My upcoming build is a daylight basement, and i have been dreading the form plywood. I am not a spring chicken and my back does not like that stuff much.
Now I am kicking around ICF as an alternative. You get instant R23, and a piece of form that weighs 7 pounds each.
I am thinking I can dig and prep, put in edge forms and bar, and then hire a finish crew to pour the slab with thickened edges for footing bearing.
Then I could stack the ICF myself and get a crew back on pour day.

Xringer · 02-28-22, 08:54 PM

Wow, I never even heard of this before.. (Or I did and forgot about it).
I've never seen it used around here. Maybe town code forbids it?
This old video is pretty nice.. https://youtu.be/MRipzKkeQik

nibs · 02-28-22, 09:34 PM

Version II the damn computer ate V I.
ICF is great, materials cost when we did ours was about the same as single use plywood forms.
You may need a moisture barrier and insect proofing depending on area.
Pour your walls before you strip the footings you can use the form as a nailer for a sleeper to position the forms against, very fast and keeps things straight.
As you put the leggo blocks together, you place your rebar and conduit as needed.
If your ICF foam is thicker on one side place the thin side to the interior, gives your build the max advantage of thermal mass, When you make your bucks leave a permanent pc of 2X full width of the form with nails sticking into the concrete, and leave the wood behind when you strip out the bucks, it gives you a nailer for the windows. The building inspector may not like it, but wood cast into wet cement will not rot, the cementaceous liquids rot proof the wood. We site mixed our walls but am advised that if you pump with an overhead boom the walls do not need vibrating. Wet stab the anchor bolts. And put on the roof. Yes don't stop at ground level, go all the way to the roof line.
Yes concrete is not the greenest, but if you do it right you are building walls that will last 500 years or more so may save many trees.
Have many years working with cement, forming, placing, and managing.
The house I am sitting in is largely concrete and has really good thermal characteristics.
Do put pex loops into the floor, heating the floor is so fine.
Good luck.
If you PM me I will give my email address and am happy to look over your shoulder from afar.

skyking · 03-14-22, 09:37 PM

I'll stop at the foundation on this build, as I prefer lightweight framing methods and have more experience. Darling Wife ( DW) does not want concrete floors so we will have traditional joists and subfloors.
Things have changed with the design and it may not be a daylight basement, just a deluxe tall crawlspace with a rat slab.

nibs · 03-14-22, 10:33 PM

My favorite wife loves the warmth of the tile on concrete floor with the hydronic going. minus 28 one morning here and we were both barefoot having morning tea.
Come in from the cold and snow, and take off our booties and socks to warm our feet.

01-09-22, 12:27 PM	#1
skyking Helper EcoRenovator Join Date: May 2011 Location: Western Washington Posts: 91 Thanks: 47 Thanked 20 Times in 13 Posts	ICF basement walls My upcoming build is a daylight basement, and i have been dreading the form plywood. I am not a spring chicken and my back does not like that stuff much. Now I am kicking around ICF as an alternative. You get instant R23, and a piece of form that weighs 7 pounds each. I am thinking I can dig and prep, put in edge forms and bar, and then hire a finish crew to pour the slab with thickened edges for footing bearing. Then I could stack the ICF myself and get a crew back on pour day.

02-28-22, 08:54 PM	#2
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	Amazing! Wow, I never even heard of this before.. (Or I did and forgot about it). I've never seen it used around here. Maybe town code forbids it? This old video is pretty nice.. https://youtu.be/MRipzKkeQik __________________ My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less..

02-28-22, 09:34 PM	#3
nibs Apprentice EcoRenovator Join Date: Jun 2010 Posts: 206 Thanks: 1 Thanked 18 Times in 17 Posts	Version II the damn computer ate V I. ICF is great, materials cost when we did ours was about the same as single use plywood forms. You may need a moisture barrier and insect proofing depending on area. Pour your walls before you strip the footings you can use the form as a nailer for a sleeper to position the forms against, very fast and keeps things straight. As you put the leggo blocks together, you place your rebar and conduit as needed. If your ICF foam is thicker on one side place the thin side to the interior, gives your build the max advantage of thermal mass, When you make your bucks leave a permanent pc of 2X full width of the form with nails sticking into the concrete, and leave the wood behind when you strip out the bucks, it gives you a nailer for the windows. The building inspector may not like it, but wood cast into wet cement will not rot, the cementaceous liquids rot proof the wood. We site mixed our walls but am advised that if you pump with an overhead boom the walls do not need vibrating. Wet stab the anchor bolts. And put on the roof. Yes don't stop at ground level, go all the way to the roof line. Yes concrete is not the greenest, but if you do it right you are building walls that will last 500 years or more so may save many trees. Have many years working with cement, forming, placing, and managing. The house I am sitting in is largely concrete and has really good thermal characteristics. Do put pex loops into the floor, heating the floor is so fine. Good luck. If you PM me I will give my email address and am happy to look over your shoulder from afar. Last edited by nibs; 02-28-22 at 09:44 PM.. Reason: Add a footnote

03-14-22, 09:37 PM	#4
skyking Helper EcoRenovator Join Date: May 2011 Location: Western Washington Posts: 91 Thanks: 47 Thanked 20 Times in 13 Posts	I'll stop at the foundation on this build, as I prefer lightweight framing methods and have more experience. Darling Wife ( DW) does not want concrete floors so we will have traditional joists and subfloors. Things have changed with the design and it may not be a daylight basement, just a deluxe tall crawlspace with a rat slab.

03-14-22, 10:33 PM	#5
nibs Apprentice EcoRenovator Join Date: Jun 2010 Posts: 206 Thanks: 1 Thanked 18 Times in 17 Posts	My favorite wife loves the warmth of the tile on concrete floor with the hydronic going. minus 28 one morning here and we were both barefoot having morning tea. Come in from the cold and snow, and take off our booties and socks to warm our feet.