astm steel grade to support basement wall
astm steel grade to support basement wall
(OP)
The wall in my basement has cracked at the frost line and has started to bow approx 1/2". I have researched several systems to stabilize the wall and I am leaning towards a system that uses c channel anchored to footing and the ceiling rafters. The channel is pinned at the floor first then the top of the channel is pushed towards the wall via a bracket mounted between the floor rafters actually bending it to conform to the bow in the wall. This is supposed to keep pressure on the wall and eliminate any further bowing. I have a couple of estimates and given the materials and labor involved the price is way out of line, $4000.00 to install 7 pieces. Given the pricing and labor involved I am planning on doing this project myself. I have been in manufacturing / fabrication for the last 12 years and know I can install all 7 units in under 8 hours. I have been told to use carbonized steel for the c channel because of strength. My problem is there are several types of carbonized steel and I know some of it can be brittle. Can someone please suggest a ASTM # for the proper grade of carbonized steel to use for such a project. I am also curios what everyone here thinks about the actual process of stabilizing the wall.
Thank, you in advance for your suggestions and comments
Pat
Thank, you in advance for your suggestions and comments
Pat






RE: astm steel grade to support basement wall
Most standard steel channels in the US are ASTM A36.
This is carbon steel (don't know of and never heard of carbonized steel). It would be found at any local steel fabrication facility in your vicinity.
The steel has a minimum yield strength of 36,000 ksi (thus the A36).
Laying a channel flat to the wall with the two flanges perpendicular to the wall may help eliminate the potential for the wall to collapse inward. However, I would expect that the inward bowing would continue a bit due to the high lateral earth pressure on the wall. By laying the channel flat, you are only getting use of the weak axis bending of the channel.
We have stabilized basement walls in the past, but used wide flange shapes to do this as they incorporate theie strong axis bending and are thus stiffer.
One of the key things you should consider is minimizing the lateral pressure on the wall (in addition to any supplementary steel strengthening). Some possibilities are reducing any ground water that gets to the soil behind the wall. This can be accomplished by ensuring that all roof drains are sent away from the wall, that the ground above quickly drains water away from your house, and that your wall has some kind of working drain system behind it - where ground water can be captured and pumped or piped away.
RE: astm steel grade to support basement wall
If I can use the ASTM A36 then my material cost will only be $175.00 for the channel and I figure another $100 to $200 for miscellaneous materials, anchors, drill bits etc. This is a far cry from the $4000.00 I was quoted.
Thanks again for all of your help and comments, I really appreciate it.
Pat
RE: astm steel grade to support basement wall
Most structural-type steel has a similar modulus of elasticity (E) that is 29,000,000 psi. This is the materials stiffness (how much it stretches under load...so his shapes and the ones from a fabricator or other shop would depend on their shape only for the job at hand.
You are probably OK in doing the work yourself...the only issue is what shape, what connection to the slab/floor and what spacing to adequately resist either the load or some level of acceptable bowing....
Here I go being a salesman, too, but you might want to hire a local structural engineer just to help you out with the concept. You might find one who would take a couple of hours to simply check out your basement and do a few calcs to give you a better handle on the layout. He'd probably charge between $65 and $100 per hour - a couple of hundred bucks might well spent money.
RE: astm steel grade to support basement wall
Once again, thank you for your time
Pat
RE: astm steel grade to support basement wall
www.acec-mi.org
RE: astm steel grade to support basement wall
A.C.I. #530 the maximum spacing for external reinforcement of the masonry wall, is 4ft., with a 2.5 safety factor
Consider using composites http://www.fortressstabilization.com/whatsnew.html
Consider the problem of water intrusion too.
RE: astm steel grade to support basement wall
It's pretty simple; "deadman" plates are installed in postholes in the yard, threaded rod ties the vertical channels to the deadman.
There isn't anything special about the system, except for the profit margin. Two 40 ft walls at a total price around 5-6 thousand. I think the guy on the phone quoted seven beams per wall.
I don't mind their asking price. I assume the contractors have their dry spells, and a need to work with serious customers who truly value the effort.
I just think I can do it, myself.
Whatever the threaded rod is, or isn't, I assume it's coming from standard lengths. McMaster Carr shows all variety of threaded rod in 6 foot and 12 foot lengths. I will work with 6 foot length, 7/8" by 9 (N.C.). Will use zinc-plated, though 18-8 and other stainless is available. Can't imagine "threading the needle" over any longer distance.
Channel? Thinking of 6" channel. When I show up at the used steel yard, I would also seriously consider 5 by 5 angle.
And of course, my investigations brought me to eng-tips.com
RE: astm steel grade to support basement wall
http://www.jlconline.com/cgi-bin/jlconline.storefront/3f18c0eb0091e00c271a401e1d29063b/Product/View/9503prac
"Practical Engineering: When a Block Foundation Cracks"
Pay the three bucks to access the article, it's a bargain.
RE: astm steel grade to support basement wall