I know I have seen a discussion on this before but I cannot seem to find it. We are doing a 34x38 and will be doing a full basement. Just haven't decided on block or poured. I can tell you I will be having truss floor joists so I can an open floor in the basement. What is the benefits of each? Anything I have to worry about other than drainage around the back fill? Thoughts?
I can tell you I'm going with block, based on cost. 24 x 40 poured walls/footers = approx $9500.00 using local contractor
Block wall/footers = $5000 using local amish labor (well known for masonry skill)
I believe the single most important factor is drainage! I'm going to go overboard on drainage and waterproofing for sure.
I did two posts on each method about a year ago.
http://countryplans.com/smf/index.php?topic=10917.msg139223#msg139223
http://countryplans.com/smf/index.php?topic=10916.msg139408#msg139408
The difference in cost between the two methods would be a few hundred dollars for a DIY job.
If I could rent the forms, I would call a friend and pour. A few days of setup, one day of pour and you are done. With a good chute, site, and truck operator you should be able to have the truck dump the concrete right into the forms. Many concrete form manufactures have guides to how to add steel to put them together. You can read about them in the link I posted for poured foundations. I couldn't rent the forms and I was worried about being able to reuse the built forms for my build, so I went with block.
With walls tall enough for a basement, I believe you will probably want rebar. I did a guide to block wall sizing charts in the building code.
http://countryplans.com/smf/index.php?topic=12374.0
I don't know what amount of backfill you will want to place against the foundation. With 4 ft of backfill and 8ft walls, you have the option of not using rebar if you are not in a seismic area. Personally, I would still consider it and call around for quotes for a pumper truck for grout for every 48", or build with thicker blocks of 10" or 12".
Some notables of block wall construction are:
http://countryplans.com/smf/index.php?topic=5690.msg92874#msg92874
http://countryplans.com/smf/index.php?topic=10852.0
I have been looking at the SBC more closely. It is supposed to add strength, water proof, and not break down over time like tar. I would consider for any method.
My estimate is it would cost around $3,000-$3,500 in materials for the walls regardless of the method you use.
Thank you guys for the replies. And thank you squirl for the links. I will save the links as a reference. I know that either way I go, I am adding rebar to the walls of the basement.
Any thoughts on the polystyrene blocks that you fill with concrete? I have heard good things about them getting an R rating of about 54 or so. If cost is the #1 factor they may be eliminated quickly as I know they cost a bit more, but they are supposed to be very easy to set up and you just pour in the concrete straight from the chute.
I think you're talking about ICF, or Insulated Concrete Forms. That's what I'm building with. You end up with an 8" steel reinforced concrete wall, with 5+ inches of foam insulation. Very strong, tight, and cozy. They're not R-54, though; more like R-25 or so. There are wild claims made due to the thermal mass of the concrete, but they are not based in fact. They are not cheap, even DIY. I'm using Fox Blocks, and the forms run about $3.25 per square foot of wall area, plus you have the concrete and re-bar. It's also a lot more complicated than stack and pour; there has to be a complete bracing system installed to align the walls and keep them straight during the pour, and the pouring itself requires skill to fully consolidate the concrete and care must be taken not to fill too fast or you can blow out the forms. I am working with an experienced ICF contractor who is advising me, and I hired him to actually pour the walls. Great system if it fits the budget.
Quote from: jbos333 on August 24, 2012, 05:39:39 AM
I can tell you I'm going with block, based on cost. 24 x 40 poured walls/footers = approx $9500.00 using local contractor
Block wall/footers = $5000 using local amish labor (well known for masonry skill)
I believe the single most important factor is drainage! I'm going to go overboard on drainage and waterproofing for sure.
jbos: Let me know how the Amish work out. Since you're the next town over perhaps I will contact them when I finally get going. That sounds like a good price. Does that include the footers too? What about excavation?
That's walls and footers, no excavation or flatwork.