View Full Version : Retaining Wall Q
04-30-2003, 01:28 PM
How wide is the footing relative to the block you want to put on top of it? If you can, you can overhang the block slightly over the front by 1/2" inch and cover up most of the bow.
BTW: In making a retaining wall, there are a few things that will help it stay up:
Assuming yo are going to put a wet wall (with mortar)
* Deadman's tied into the hill perpendicual to the wall extending into the hill (depending on how high the wall is) will keep the wall from falling over again.
* Re-bar placed vertically inside the voids in the block and tied into the footing. Then fill the first three courses with concrete.
* Weep holes in the course just above the soil line, with wicks (ropes) to let the water drain out
* Adequate drainage on the backside of the wall (pea gravel and 4" corregated drain tile.)
* Metal block ties over 4th course
* Use type M or N mortar
* Utilize a cap on the top (solid block typically 2-3" tall)
:) Have fun!
04-30-2003, 02:23 PM
Thanks for the response Woodman!
I might try to straighten it out a little bit with your suggestion. Perhaps I will fill in under the slight (1/2") overhang with leftover mortar.
Good suggestion list at the end there. I'll return the cheapo generic mortar that I bought and get a better product such as you suggest.
I surfed around at lunch and found a source that advises that very slight curves to concrete block walls are acceptable provided that all joints are well buttered and that no joint is appreciably out of alignment. Hence, I think with your suggestion on the overhang, I'll have a wall that is acceptable.
A few more details on the plan:
24" wall (three courses of 8" block), 16' long.
I've dug a 12" wide trench behind and slightly below the level of the footer (not actually under the footer) and will fill it with gravel and drainage pvc (perforated) after building the wall. I plan to follow the typical plan for retaining wall drainage with plastic fabric cupping the wall and drainage trench.
Since I'd like to use the original footer, tying rebar into it will be a problem. As an alternative, I have thought of using chair rods in the joints.
As for the top, I had thought of using footlong, j-anchor bolts protruding vertically up from the top two courses to attach a 2'x6' pt sill to, so that I can build up from this wall.
Again, thanks for the advise.
04-30-2003, 09:56 PM
"Since I'd like to use the original footer, tying rebar into it will be a problem."
You could drill into the footer about 6", squirt in some epoxy, and put in your rebar. That's what we use around here when tying a new slab to an existing one. To make it stronger still, add a horizontal rebar between the 2nd and 3rd course, wire tie to vertical rods.
05-02-2003, 08:40 AM
Thanks for the advice.
Unfortunately, I had already built the wall! LOL.
I used the second of your suggestions, however, as I did plan ahead to include horizontal joint reinforcement and tied these together vertically. At the base I placed rod chairs at each joint, with the hope that this would provide some vertical stability.
In the end, I was able to lay a straight wall. We'll see how it holds up over the years. I think it will be a strong wall.
Thanks for the help.
06-02-2010, 09:18 AM
In the storage area under our house, a non-load bearing retaining wall showed signs of giving, so I helped it go (that was fun). Now I plan to put in a proper retaining wall of concrete block. The basic issue I have is that we were able to save the old footer and it could be used for a new wall, but the footer has a slight bow to it...see the attached drawing.
I would like to finish this job without pouring a new footer or augmenting the current one too much. Hence, I had thought that the problem with the current footer would not be a dramatic issue with a new retainig wall, as the bow might actually provide a bit of built in retaining stability. However, I'm concerned that with a 3/4" to 1" bow on a 16' span that the joints will lose a little bit of strength in the wall.
Am I a loony for thinking that it would be ok to go ahead and lay down this concave wall? Asthetics are not important in the least...hence, I'm using cheap concrete block.