Scenario: concrete footer poured for single story room addition. Concrete dries overnight, but footer determined to be too shallow. Holes are drilled into dry concrete, filled with epoxy and additional rebar is inserted, a layer of a bonding substance is spread over top of dry concrete footer before additional 2 to 4 inches of wet concrete is poured on top in order to raise height of footer. Is the footer sound constructed in this way, will this meet code, will the inspector be able to tell two layers were poured?
-
Welcome to the new and improved Building Code Forum. We appreciate you being here and hope that you are getting the information that you need concerning all codes of the building trades. This is a free forum to the public due to the generosity of the Sawhorses, Corporate Supporters and Supporters who have upgraded their accounts. If you would like to have improved access to the forum please upgrade to Sawhorse by first logging in then clicking here: Upgrades
JCraver
Sawhorse
So, no different than pouring a wall on top of a footer?
I'm not sure I'm seeing the problem?
I'm not sure I'm seeing the problem?
Is the top layer too thin at only 2 to 4 inches and crumble over time from the weight of walls and roof? If water gets into horizontal seam of two layers will problems arise? Should a water barrier of some kind be needed? Thanks for your input!
JCraver
Sawhorse
Those are engineering questions, and I'm not an engineer - sorry.
Is it possible to set your wall forms on the too-low footing that you have, and then add the ~2" to the top of the wall? That would eliminate most of what I think you're asking about...
Is it possible to set your wall forms on the too-low footing that you have, and then add the ~2" to the top of the wall? That would eliminate most of what I think you're asking about...
fatboy
Administrator
I'm thinking that I would ask for an engineers report and fix.
Based on the lack of responses here, I would guess most others would not be comfortable with it as described.
Now, JCravers solution with adding to the wall would be fine. Or, is the footing thickness the problem?
And, yes, you should be able to tell the difference between the concrete placement on to separate days.
Based on the lack of responses here, I would guess most others would not be comfortable with it as described.
Now, JCravers solution with adding to the wall would be fine. Or, is the footing thickness the problem?
And, yes, you should be able to tell the difference between the concrete placement on to separate days.
tmurray
SAWHORSE
The inspector should be able to tell that two layers were poured. There should be a very clear construction joint. The only time that you would need to be concerned about water affecting the bond would be if it was subjected to freeze thaw cycles. You should be able to install a water barrier if it makes you feel more comfortable.
I feel like the measures they took should be acceptable, but will likely need reviewed by an engineer to confirm this.
I feel like the measures they took should be acceptable, but will likely need reviewed by an engineer to confirm this.
To CYA, have an engineer make the call. There is nothing in the code that we can prescriptively say this is ok.
I will say, if an engineer were to propose this fix, I would have no problem moving on with it as is. Make sure that the additional layer is at minimum 3 times the size of the nominal aggregate used in the concrete.
I will say, if an engineer were to propose this fix, I would have no problem moving on with it as is. Make sure that the additional layer is at minimum 3 times the size of the nominal aggregate used in the concrete.
Unless they want to remove the existing and pour it correctly this sort of a fix needs an engineers input. An engineer in some instances may be able to justify the existing while in other situations significant work may be needed in which case it may be cheaper and faster to remove and replace.
A thin layer such as 2 to 4 inches can raise questions about the effectiveness of the dowels. It may not be possible to provide required concrete cover on hooks on the doweled rebar.
Was the surface concrete removed to assure a good bond.?
If the epoxy is allowed to set up before the new concrete is poured then you have made things worse since you have eliminated any bond between the two layers of concrete.
The fact that this repair was undertaken without involving an engineer suggests an out of control contractor. In any case this repair would need to be approved by the building official before implementation. Was it?
Inspectors and building officials need to better understand the limits of their expertise.
A thin layer such as 2 to 4 inches can raise questions about the effectiveness of the dowels. It may not be possible to provide required concrete cover on hooks on the doweled rebar.
Was the surface concrete removed to assure a good bond.?
If the epoxy is allowed to set up before the new concrete is poured then you have made things worse since you have eliminated any bond between the two layers of concrete.
The fact that this repair was undertaken without involving an engineer suggests an out of control contractor. In any case this repair would need to be approved by the building official before implementation. Was it?
Inspectors and building officials need to better understand the limits of their expertise.
Paul Sweet
Sawhorse
I would have used the original footing as a mud mat and poured one the correct thickness on top of it.
conarb
Registered User
I don't get it, if a stem wall is going on the footing the additional 2 to 3" could just be part of the stem wall widened at the base, there should be steel sticking up anyway, if a slab is going on the footing just thicken the slab around the perimeter, again steel should be sticking up, if a mudsill is going on the footing just thicken the mudsill from 2x to 3x or 4x and grout under it. If this footing is part of an engineered design the engineer or a Special Inspector will be looking at it anyway and he will make the call, this seems like a non-problem to me.