Changes ...

[Terry Coombs]

Well , as they say , no battle survives contact with the enemy intact ... I was pricing block vs poured concrete today , with the mistaken expression that block would be cheaper - what a surprise , concrete is half the cost for materials only . Well , actually less than half . because I'm getting the floor too for just over half . Anyway , and this would come up with block too , I want to apply a waterproofing to the portions of the poured walls that will be below grade . I'm seeing crystalline type sealers , and know nothing of the technology . Any of y'all have experience with this stuff ? Is it cost effective ? I was ready to apply a coat of asphalt emulsion/felt/emulsion , not knowing about this other stuff .

[rbowman]

Are you figuring in the forms? I worked on a volunteer project where the guy in charge tried to cheap out and build forms out of scrap laying around the site. He got a floor too when the forms let go. We weren't prepared to strike it off, so it set up lumpy.

[Ed Pawlowski]

I'd use ICFs (Insulating Concrete Forms) and have a poured foundation already well insulated. Something like

[Terry Coombs]

I'm researching using some 7/16 OSB , then reusing it for exterior sheathing or maybe on the roof . Question there is what to use as a release agent . Diesel has been suggested but not sure if the odor will be a problem later . Floor will be poured first as a monolithic (?) slab with the footings integrated into the slab . I also plan to use a poly vapor barrier under the slab , thickness is yet to be decided .

[Terry Coombs]

I'm not sure that's cost-effective here . It just doesn't get that cold for that long . Exterior walls will be native stone with 1" foam behind it . Not sure if I was clear , this cellar will be 10 x 16 under a 24 x 24 kitchen . There will be a pretty big crawl space which I might just use to grow mushrooms ...

[gfretwell]

Florida is the land of the monoslab. Be sure to leave the footer part of the slab free of the visqueen so you can use it as a Ufer electrode and tie this into the ground electrode system. If you are using a contractor to pour the walls, they will have the forms. They usually use a commercial product for the release agent, designed for the form material they use.

[Terry Coombs]

I've done a bit more research , found that the walls will cost about the same either way . I was thinking of going with 4" walls , found that 6" is the minimum recommended . That makes the cost so close that it's actually going to be easier to do the block . Also , doing block means I don't have to do a marathon mix-n-pour . I'm probably being too anal about controlling costs , have to keep reminding myself that a dollar spent now will probably save 3 later .

[gfretwell]

There is no way you can "mix and pour" that much concrete cheaper than just getting a chain of redi mix trucks and a pump. This won't even be a long day. It will be about 54 sq/ft of wall per yard at 6". You usually get 10 yards on a truck.

[Terry Coombs]

The problem is that this is a small community and the local redimix doesn't HAVE a pumper . Due to the location , no way to get a truck close enough and I'm sure as hell not going to move 6 1/2 yards on concrete in a wheelbarrow . Turns out that total cost for materials is pretty much a push either way , and blocks will be easier for me in this case . As Oren suggested , there will be some of the spaces filled with concrete and reinforced with rebar . Moisture intrusion shouldn't be a problem as long as the landscaping profile directs runoff away from the house . I plan on waterproofing of some type for that portion that will be below grade , about half the total wall area .

[gfretwell]

Most of the pumps we see here are towed behind a pickup truck. It is more price competitive to separate the pump from the truck., The pump and the truck stay near the street and they just drag a hose to the work. They do have some big snorkel trucks nut you usually see them on commercial jobs. I have pumped well over 100 yards of concrete here at the house and my wife pumped thousands when she was building houses.

[Ed Pawlowski]

Mushroom growing is different from a habitable space. The ICFs are often used in the south to save on AC costs. In the north, basement insulation can save a bundle. I'd have two inches of foam under the slab here.

[Harry K]

Block is a very flexible method but remember to add in the time and cost to lay it. I've BTDT and would hire it laid next time. It also is not as "sturdy" as poured. Very easy to pull a wall down once any top weight is removed.

Harry K

[Harry K]

I did my three season porch (enclosed a patio). Rsulted in a 3' back wall against a slope. Waterproofed with some of the paint-on fiber containing w aterproofing. Haven't had a problem with moisture. Basement used to be wet but not after I laid a drain pipe below that knee wall footing.

[Terry Coombs]

It's going to be hard to remove the weight of half a house sitting on top ... this cellar won't be entirely underground , bury depth will vary from about 5 1/2 feet to just under 3 . There will be rebar every 4 feet and if I can figure out how I might add some horizontal rebar about 2/3 up the wall . I was talking to a neighbor and he's used that asphalt type waterproofing and liked it . Water intrusion is not my biggest worry but why not take steps now . As far as time , the only thing I have more of than time is ... time .

[gfretwell]

Block is a perfectly good building material but if you are a one man band, it is slow. As long as that is OK for you, go for it.

[gfretwell]

When you do this you use "hooks", rebar with a 90 degree bend at the top so you have a foot or so to tie to the tie beam rebar at the top and the footer rebar at the bottom. The hook from the top laps the hook from the bottom and you knock a hole in the wall to tie them together. You put a scrap of plywood over the hole when you pour the doweled cells solid.

The other option is top form up the top 16" and pour a solid tie beam.

[gfretwell]

These days it is "hard nails" in a nail gun. I haven't seen a cut nail used in a couple decades.