Concrete questions

[anderhill]

I am building a small home, 24 x 42, and was told I only need FPSF to go with the slab as my property is Gravel. Is there a reason why, when looking at cross sections of FPSF they kind of feather/slope into the slab? I am thinking about using something like Logix Blocks for the FPSF, will this work? Also they say 4" for the slab is all that is needed, however there will be a loft over approx half of the structure, do I need piers where the bearing wall will be for the loft? I know concrete is scarey stuff, if I had the budget to do it I would have someone do it for me, but.... Also should we cut in contraction joints

 

[Bondo]

Ayuh,.... What's FPSF,..??

Anywhere the buildin' will be addin' weight, needs to the thickened to a footer,...
The footer holds up the house,....
The rest of the slab is just nice to walk on,...

'n Yes,... Cut in joints to limit crackin' randomly,...

 

[willymakeit]

Are you talking about frost protected shallow footings?
I have no experience with these but HUD has a 56 page guideline with a PDF.
Where are you at?

 

[rburke65]

I'd go with TTRV unless you have any clay, then I'd do FPTY.

 

[anderhill]

Yes, Frost Protected Shallow footings, I've had a couple contractors tell me this is all I need in that area. Seriously I would almost call it a gravel pit... Brainerd, MN

 

[Radix2]

The reason you see the feather/slope in the insulation is so that it sheds water away from the building as it is absorbed into the ground around the perimeter.... if you are talking about the outside perimeter insulation?


Logix blocks are ICF forms which will let you pour an insulated foundation wall, they are a good choice, but would be for a normal deep foundation not an FPSF. Or are you considering pouring walls above the foundation?

 

[kbs2244]

The foundation is what everything else is built on.
It is not the place to cut corners.

Get a pro.

Your house will be sitting on it forever.

 

[Ggg]

Is there a link to this HUD PDF?

 

[Firebrick43]

I am building a small home, 24 x 42, and was told I only need FPSF to go with the slab as my property is Gravel. Is there a reason why, when looking at cross sections of FPSF they kind of feather/slope into the slab? I am thinking about using something like Logix Blocks for the FPSF, will this work? Also they say 4" for the slab is all that is needed, however there will be a loft over approx half of the structure, do I need piers where the bearing wall will be for the loft? I know concrete is scarey stuff, if I had the budget to do it I would have someone do it for me, but.... Also should we cut in contraction joints

You need footers were the post will be. The should be poured when the other footers are poured and covered with the vapor barrier. Don't pin them together just pour the slab over.

If you use icf it needs to be a standard frost wall and to the depth required in your local as radix2 mentioned. If it's a rectangular foundation with no funky kick outs and such it can be a DIY project. If you do icf make sure you have access to the specific vertical bracing ment for icf. Don't try to cobble together bracing, everyone I have talked to regretted it as the had bows and blow outs. The commercial bracing allows you to quickly straighten the wall before the concrete sets up.

The slab prep can be DIY but hire the placement/finishing out.

As for cutting the concrete? My 28x30 garage and 28x50 are both crack free. I have 12" of compacted crushed stone and it was unrestrained to the icf walls and post footers. So as it shrank a 1/4"+ gap as formed at the perimeter as formed because the slab could shrink. I also sprayed water for a week to keep the slab from curing.

On the other hand my composite steel slab is about the most restrained piece of concrete and it cracked predictably in 12'~ squares.