Slab on grade, mins the slab...

TechShop · 12-22-20, 09:57 PM

I happened upon this is pretty interesting slab-less "slab on grade" video today (link below).

I'm intrigued, and if I build another home on my land, I'll probably consider this method. The only thing that comes to mind is, what are the moisture control implications of building this way.

https://www.youtube.com/watch?v=NbC-...ature=youtu.be

https://youtu.be/NbC-EfQ_u3E

Daox · 12-23-20, 10:33 AM

Very interesting idea. The elimination of such large use of concrete is definitely a cool idea.

nibs · 01-28-21, 05:01 PM

The foam will bridge any minor defects in the grade, the down sides that I can see, infloor heating would be a bit tricky if you wanted it. (We love our warm floor), and if you are bermed at all (we are) you would lose the horizontal slab holding the walls against the soil loading at the foot of the walls.
The other problem you might have would be with building inspectors going cross eyed,especially on the sani side of things.
I would only do it on very well drained soils in a relatively dry region.
You would also need to deal with termite control.

People criticize concrete as being "not green" in our house we used concrete extensively including for interior walls, We bought bags of cement, found a sand pit near by and brought our sand in by pickup truck, site mixed all the cement, using strong mixes with fiber, and water reducers and would do the same if we had to start over.
if you think of concrete as lasting for hundreds of years it suddenly moves way up the green scale.

TechShop · 01-28-21, 07:32 PM

Quote:

Originally Posted by nibs

The foam will bridge any minor defects in the grade, the down sides that I can see, infloor heating would be a bit tricky if you wanted it. (We love our warm floor), and if you are bermed at all (we are) you would lose the horizontal slab holding the walls against the soil loading at the foot of the walls.
The other problem you might have would be with building inspectors going cross eyed,especially on the sani side of things.
I would only do it on very well drained soils in a relatively dry region.
You would also need to deal with termite control.

People criticize concrete as being "not green" in our house we used concrete extensively including for interior walls, We bought bags of cement, found a sand pit near by and brought our sand in by pickup truck, site mixed all the cement, using strong mixes with fiber, and water reducers and would do the same if we had to start over.
if you think of concrete as lasting for hundreds of years it suddenly moves way up the green scale.

I pretty much agree with all of the above.
As a long term structure, it's hard to beat reinforced concrete.

I think in-floor heating wouldn't be too terrible if one of those grid-work style systems were to be used.

I have a 62x40 slab on grade 6" thick and I certainly appreciate my in-floor heat and the "flywheel" effect that the huge mass of concrete offers.

The difference in opening a garage door with a heated slab vs an unheated slab is amazing.

In a power outage at the coldest winter temps, I can get by without running my heat pump for almost 24 hours without feeling too cold.

All that said, this slabless concept is intriguing to me and I like to keep stuff like that on my radar.

12-23-20, 10:33 AM	#2
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	Very interesting idea. The elimination of such large use of concrete is definitely a cool idea. __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

01-28-21, 05:01 PM	#3
nibs Apprentice EcoRenovator Join Date: Jun 2010 Posts: 206 Thanks: 1 Thanked 18 Times in 17 Posts	The foam will bridge any minor defects in the grade, the down sides that I can see, infloor heating would be a bit tricky if you wanted it. (We love our warm floor), and if you are bermed at all (we are) you would lose the horizontal slab holding the walls against the soil loading at the foot of the walls. The other problem you might have would be with building inspectors going cross eyed,especially on the sani side of things. I would only do it on very well drained soils in a relatively dry region. You would also need to deal with termite control. People criticize concrete as being "not green" in our house we used concrete extensively including for interior walls, We bought bags of cement, found a sand pit near by and brought our sand in by pickup truck, site mixed all the cement, using strong mixes with fiber, and water reducers and would do the same if we had to start over. if you think of concrete as lasting for hundreds of years it suddenly moves way up the green scale.