Digging the Footings

The time has arrived to actually start digging the footers or footings as people interchangeably call them. The footings are poured to form the perimeter of the house upon which the stem walls are placed, which in turn support the regular exterior walls of the house, which in turn supports the roof. So basically, the entire weight of the structure rests on the footings.

It feels like it took a long time to get to this point in the project, the time when I can finally see ground-work being done and the first sense of genuine construction. There were so many things that had to be done before getting to this point. Getting plans drafted, approved, and paid for. Learning that the property didn’t have existing taps for sewer and water and having to install them in that order (sewer always goes before water) and repaving the asphalt that was removed to access both lines. Removing the old fencing that separated my lot from the neighbor’s lot plus several trees and palm trees. Grading the land and putting in a certified pad.

The footings themselves have also been a sore spot, a financial sore spot to be accurate. Because of the crappy soil on the lot, the footings have to be 3 feet in depth. Normally, footings are 12 inches or 18 inches in depth. Thus, this project requires two to three times as much excavation and concrete and rebar as a normal project would. What’s doubly frustrating is that when you look around the neighborhood, the houses are all built on normal foundations and while it is conceivable my lot is uniquely porous, I honestly doubt it. And those other houses seem to have lasted at least 80 years without issue, so I have no idea why the code is so demanding.

We also had to build a “certified pad” before digging and pouring the footings. This meant dirt had to be removed from the surface of the lot and then the soil compacted with some sort of steamroller-thing and then additional dirt brought onto the site and further compacted so that the house, including the footings, stem wall, and slab-on-grade would all rest on stable soil. One purported benefit of the certified pad was that we could use the depth of the pad itself as part of the total depth of the footings. For whatever reason, however, the depth of the pad ended up being just 6 inches deep above grade, so we still had to dig 30 inches below the regular lay of the land for the footings. I guess I had thought the certified pad would be at least 12 inches tall and thus we would only have to dig 24 inches into the soil, but that is not the case.

Just digging the footings was the starting but not the ending point. I had to call the City’s Planning and Zoning Department to schedule an inspector from the city to come and approve the footings. The inspections are segmented. The first inspection is after the footings have been dug and the rebar has been placed and tied. The inspector will check to make sure the footings are at the right depth, the rebar is tied properly, and it all has to be in the right place in terms of distance from setbacks and property lines. Planning and Zoning doesn’t give you the telephone number for the inspector they intend to send, so you just give the Planning and Zoning your telephone number and on the day of inspection, they call an hour beforehand and go to inspect. My concrete guy says he usually isn’t there during inspection, the inspector either leaves a green tag–presumptively “good”–or you can access some electronic system to read comments when the inspection turns up things that need correction.

Another thing to think about is penetrations to the structure–for things like the sewer line– that have to go past or better put through the footings, as you want to “block out” those areas of penetration before pouring the concrete. We have not placed those blockings in yet, but from what I understand, we will put a piece of styrofoam (or something like that) where we want the penetration(s) and the wet concrete just ends up surrounding the block during the pour. After you remove the styrofoam, it leaves a cavity. Dumb as it sounds, I’m curious if the foam blocking is simply some sort of styrofoam tube or an actual rectangular shaped block, as pipes are circular so I suspect the styrofoam should also be circular.

Additionally, we will have to put a “ground wire” to attach to the rebar, which is also called a “ufer” (the name of the guy who invented the process was a Mr. Ufer). My concrete guy said the ufer is about 20 feet long below ground and needs to be tied to the rebar, and then another 10 feet of wire needs to be above ground to connect to the electrical box. The ufer takes the energy from an electrical surge and distributes it through the rebar and into the surrounding concrete and then into the surrounding soil. The concrete is continually absorbing moisture from the surrounding soil and thus becomes relatively conductive, so electricity goes from the ufer to the rebar to the concrete and finally into the soil. My GC said that there were ways of tying the rebar to act as a ufer and avoid having to pay for 30 feet of copper per unit, but my concrete guy is unfamiliar with this. The timing of the ufer installation is important; people will steal copper and we want to place the ufer just before the inspector comes and pour concrete immediately thereafter so that the ufer isn’t visible for theft.

There are more minor details that were done or have to be done. We had to put a hose bib on the water line for access to water and put a key on it, because otherwise people will open the water valve and…take a shower or who knows. The rebar end points need to have little plastic caps put on to prevent someone from hurting themselves if they were to fall into the trenching. Just, lots of little details, but at the end of the day, I’m hoping to have a very strong foundation that is completely up to code. The foundation is truly the foundation of the project; a bad foundation means a bad structure, which means a sad project.